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Oil and gas industry continues to the increasing demand of more cost-effective well design and operations. Thus, team successfully eliminated intermediate casing string from the design thereby achieving not only a 33% reduction in dry hole cost/meter, but also delivering wells and producing oil 25% faster than before. Removing an intermediate casing string resulted in a longer open hole (more than 2000 mMD) which by default created new challenges which had to be dealt with and solved without compromising the targeted cost saving. The challenges can be summarized as follow: • Combining loss of circulation zone with unstable shale formations in one section. • PPFG uncertainties. • Bit selection and design optimization. • BHA selection and drive optimization. • Running wireline logging through a long open hole. • Running casing and having good quality cement. • Hole cleaning and displacement efficiency when changing mud systems. • Proper contingencies in place to meet the required completion strategy. Risk assessment, feasibility studies, workshops, and co-operation among all involved personnel has been conducted to ensure that this design optimization would result in positive outcome. Since the first implementation in 2019, more than 17 wells have been successfully delivered and completed in Best in Class performance based on latest update of Rushmore data tracking. The longest open hole section of 2790 m measured depth (MD) with total depth (TD) of 3910 mMD has been achieved generating above 800 Kusd saving per well, thus setting new benchmarks for the field and opening up new opportunities for the future. All this ensure Process Safety and compliance with Well Delivery process. This paper not only describes how two string design was successfully engineered and executed but also serves as a guide for selecting proper candidates for this design and an operational guide for two section wells design to ensure that these challenging long open hole will be successfully drilled while minimizing risks.

In sand casting, Fused Deposition Modeling (FDM) printing by using Poly Lactic Acid (PLA) filament is one of the innovative foundry technologies being adopted to substitute traditional pattern making. Several literatures have reported the influence of process parameters such as raster angle and print speed on some mechanical properties of FDM-printed, PLA-prototypes used in other applications. This study investigated the effects of interior fill, top solid layer, and layer height on the compressive strength of rapid patterns for sand casting application. Different values of the process parameters were used to print the pre-defined samples of the PLA-specimens and a compression test was performed on them. The coupled effects of the process parameters on compressive strength were investigated and the optimum values were determined. Interior fill of 36%, layer height of 0.21 mm and top solid layer of 4 were found to produce a FDM-printed, PLApattern that sustained a compaction pressure of 0.61 MPa. A simulation analysis with ANSYS® to compare failure modes of both experiment and model shows a similarity of buckling failure that occurred close to the base of each specimen.

In order to satisfy the machining requirements of aero-engine casing in modern aviation industry, this paper investigates three main issues during the design and development process of a five-axis machine tool with high accuracy, stiffness and efficiency, including whole structure design, key components design, and supporting stiffness design. First, an appropriate structure of five-axis machine tool is determined considering the processing characteristics of aero-engine casing. Then, a dual drive swing head and a compact motorized spindle are designed with enough drive capability and stiffness, and related structure, assembly method, cooling technology, and performance simulation are given in detail. Next, a design method of supporting stiffness of guide is proposed through the deformation prediction of the spindle end. Based on above work, a prototype of machine tool is developed, and some experiments are carried out, including performance tests of swing head and motorized spindle, and machining of a simulated workpiece of aero-engine casing. All experimental results show that the machine tool has satisfactory accuracy, stiffness and efficiency, which meets the machining requirements of aero-engine casing. The main work can be used as references for engineers and technicians, which are meaningful in practice.

Slip is one of the most critical components for the frac plug, which would lodge into the casing and lock the frac plug in place during the setting and anchoring process. However, fracture failure of slip significantly affects the hydraulic fracturing effects and has attracted tremendous attention. In this paper, a three-dimensional contact model is applied to explore the setting process of slip. The effects of key structural parameters such as apex angle, inclination angle, and wedge angle on the contact characteristics of slip are systematically investigated. Numerical results indicate that the maximum contact stress appears at the contact area between slip tooth and the casing's inner wall. Besides, the maximum contact stress generally increases with the increase of apex angle and inclination angle, while decrease linearly with the rise in the wedge angle. Experimental results show that the slip teeth get blunt and appear severe plastic deformation, which arises from stress concentration. Comparison of biting area indicates that the experimental results are about 21.3% larger, which still have a reasonable agreement with the numerical results. These obtained results can guide the parametric selection of plug slip and other similar components.

Hearing disability is commonly observed in old age person. It is observed that for the age limit 55 to 80 years around 40% of individuals are facing age related hearing loss. Light weight hearing aid made of composites are being used very frequently. There are two types of hearing aids canal: In-the-ear (ITE), Behind-the-ear (BTE); out of which BTE is commonly preferred. Around 38% of BTE aids fail in their operation due to the impact generated by mishandling. Drop test measures the impact and fragility of the component. It particularly determines how the component performs under external the impact of the load. In the present study, drop impact numerical analysis has been carried out using ANSYS workbench explicit dynamic module for hearing aid casing. Three different polymer materials namely Acrylonitrile butadiene styrene (ABS), Polylactic Acid (PLA) and Thermoplastic Polyurethane (TPU) have been used. The main purpose of the analysis is to determine the maximum deformation and critical area when it falls on the ground. Load conditions like impact velocity and height have been considered as per the IS standard IS: 11052–1984 for the flat and side drop test. It is observed that maximum deformations were observed in TPU as compared to PLA and ABS irrespective of velocity. In addition, contact force was observed maximum in PLA and minimum in ABS irrespective of velocity which leads to minimum internal energy for PLA. TPU and ABS could be the second choice of material after PLA for the hearing aid casing.

Sustainable and renewable energy is the need of the hour. Scientists and Engineers around the world are pushing for electric vehicles and electrically run machines to save the environment from pollution and global warming, to create a sustainable planet for us humans to live. The aim of the present research work is to understand the heat transfer characteristics of an electric motor casing made of Aluminium Metal Matrix Composites (AMMCs) so as to implement such casings on a larger scale. As aluminium composites are light in weight, this would improve the performance and efficiency of the electric motor in the long run, and when thought about at the global level considering the new upcoming age of electric vehicles, the slightest of improvements could produce a major impact in the upcoming years. The CAD model of the casing is designed using Solidworks software. This model is used to conduct Finite Element Steady State Heat Transfer analysis in Ansys software to study the heat transfer characteristics. Five AMMCs are chosen for analysis. A comparative study is made based on the weight of the casing and the heat transfer characteristics for each material. Al/Graphite composite is found to produce promising results in the heat transfer domain.

A significant part of an automobile is the gear box (tractor) casing. The primary objective of using the Gearbox casing is to embrace and allow the transmission of the Gearbox. The Gearbox is a mechanism that regulates speed or torque between the flywheel and the differential. The main shaft and lay shaft with gears equipped embraces the gear box. This paper deals with the modeling and study as an alternative material of the gear box casing for a tractor with E-Glass. Through the development of the simulation software platform ANSYS, it is analyzed statically with different design parameters such as web thickness, gear box housing depth and gear box housing thickness. In order to determine the stress produced and deformation degree, the gear box with traditional Grey cast iron is analyzed; it is then compared with the housing of the E-Glass Gear box. The outcome will be studied and evaluated after study, various combinations of design parameters were used to achieve the design that minimum output in failure at higher load s has better deformation characteristics. Finally, in order to design the gear box housing, an optimized design parameter is obtained.[1]

Controlled-source electromagnetic (CSEM) measurements are complementary data for magnetotelluric (MT) characterization although its methodology on land is not sufficiently developed and tested as in marine environments. Acquiring expertise in CSEM is crucial for surveys in places where MT cannot be performed due to high levels of cultural noise. To acquire that expertise, we perform CSEM experiments in the Vallès fault [Northeast (NE), Spain], where MT results have been satisfactory and allow us to verify the CSEM results. The Vallès basin is relevant for potential heat generation because of the presence of several geothermal anomalies and its nearby location in urban areas. In this article, we present the experimental setup for that region, a 2-D joint MT+CSEM inverse model, several 3-D CSEM simulations in the presence of metallic casing, and its comparison with real data measurements. We employ a parallel and high-order vector finite element algorithm to discretize the governing equations. By using an adapted meshing strategy, different scenarios are simulated to study the influence of the source position/direction and the conductivity model in a metallic casing presence. An excellent agreement between the simulated data and analytical/real field data demonstrates the feasibility of study metallic structures in realistic configurations. Our numerical results confirm that metallic casing strongly influences electromagnetic (EM) responses, making surface measurements more sensitive to resistivity variations near the metallic structure. It could be beneficial getting higher signal-to-noise ratios and sensitivity to deep targets. However, such a casing effect depends on the input model (e.g., conductivity contrasts, frequency, and geometry). This work was been developed in the frame of GEOURBAN project (PCI2018-092943 and PCI2018-093186). This work has received also partial funding from the European Union's Horizon 2020 programme under the Marie Sklodowska-Curie grant agreement N777778. Also, the research leading to these results has received funding from the European Union's Horizon 2020 programme, grant agreement N828947, and from the Mexican Department of Energy, CONACYT-SENER Hidrocarburos grant agreement N B-S-69926. Furthermore, this project has been 65% cofinanced by the European Regional Development Fund (ERDF) through the Interreg V-A Spain-France-Andorra program (POCTEFA2014-2020). POCTEFA aims to reinforce the economic and social integration of the French-Spanish-Andorran border. Its support is focused on developing economic, social and environmental cross-border activities through joint strategies favouring sustainable territorial development. The authors would like to thank the Editors-in-Chief and to both reviewers for their valuable comments and suggestions that helped to improve the manuscript’s quality. This work benefitted from the valuable suggestions, comments, and proofreading of Dr. Josep de la Puente (BSC).

It is important to increase the production rate of oil and gas as the usage of them is increasing day by day. To increase the production rate of oil and gas, design of an efficient centrifugal pump impeller plays very important role. Due to the usual submergible pump, there might be the chances for failure and it is so complex when the pump is failed. So an alternative method such as artificial lift is necessary on behalf of submergible pumps for different flow rates. In the present study, 3D simulation of impeller and its stationary flow of centrifugal pump casing are analyzed using CFD. Pressure head and efficiency of the pump for different flow rates are analyzed as well as the data from pump manufacturers are taken and have good satisfactory agreement. Finally, the structural analysis of single impeller blade is carried out by changing different materials. These data are very useful to design the pumps in manufacturing industries.

Cementing is one of the important steps in well construction. This chapter shows how to calculate the amount of additives required for mixing the different types of cement slurries. These additives provide properties of fluid loss, setting time and rate (i.e., acceleration or retardation), and reducing the friction to prevent high pump pressures on deep high-density casing jobs. Calculations to provide the proper placement for support of the casing and to ensure that the casing is anchored to prevent casing shoe movement after the cement is pumped are detailed. Other important cementing operations include pumping and placing open hole plugs and balancing the pressures, so the plug will not “U-Tube” when the pipe is removed from the plug. Finally, it is important to determine if the casing will move up (called “hydraulicing”) the hole as the different density cement slurries are pumped in place.

In this paper, a failure evaluation criterion was proposed for the bolted casing-flange structure under impact loading. Subsequently, ballistic tests with eighteen bolted casing-flange structure specimens were conducted to validate the failure evaluation criterion. Parameter studies were then carried out using the validated FE models. Both the experimental and numerical results demonstrated the accuracy of the failure evaluation criterion. The failure evaluation criterion provided a quick and easy way to determine the failure mode of the casing connection area by using the materials and dimensions of the structure. Based on the failure evaluation criterion, designing the structural failure mode of the bolted casing-flange structure to be between flange failure and bolt failure can improve the impact resistance of the connection area of the aero-engine casings. This investigation revealed that the impact failure is not the unique criterion in evaluating the containment of the casing connection area, structural failure should also be involved in the evaluation criteria.

Submarine pressure hulls, fire-tube boilers, vacuum tanks, oil well casings, submersibles, underground pipelines, tunnels, rocket motor casing, etc., are some of the examples of thin cylindrical shell structures which collapse due to buckling under uniform pressure. To enhance the buckling strength of bare cylindrical shells, one of the best solutions is to stiffen them with ring stiffeners. In this work in order to predict the shell instability failure mode (SIFM) and general instability failure mode (GIFM) FE models are generated and analysed using buckling analysis of general-purpose FE software ANSYS. The numerical results obtained using FE analysis are compared with published analytical and experimental results. Hence in the present study efforts are taken to develop FE models to predict global and shell instability failure modes of externally ring stiffened cylindrical shells by using linear FE analysis. It is proposed to use full/half bare cylindrical shell FE models (L/R ratio upto 200) to determine SIFM and FE models with shell281- Beam189 (for stiffeners) can be used to determine GIFM. The developed FE models are validated by comparing numerical results with experimental results published by Seleim and Roorda [25] . By using both proposed FE models it is possible to predict the failure modes namely SIFM and GIFM, comparing their values of critical buckling pressures. The lower pressure value can indicate the possible failure mode.

Assembly quality of aero-engine casing plays a key role in the whole aero-engine, since it is directly related to the final function and dynamic performance. However, during the design phase, the tolerance analysis is usually conducted independently without any consideration of the effect on the dynamic characteristic. This paper aims to integrate manufacturing precision with dynamic performance instability together. First, the 3-D tolerance model of the aero-engine casing is constructed based on the Jacobian-Torsor theory. The target deviation from the tolerance model is defined as the input variable into the vibratory governing equation. Then, the effect of 3-D assembly deviation on the natural frequency is studied. The corresponding frequency distributions for different vibration modes are illustrated. Finally, the mapping relationship between assembly tolerance and fluctuation ratio of natural frequency is established through the 3-D fitted surface. Under the given constraint of performance stability, the optimized tolerance zone is obtained. This work provides a significant guidance for performance improvement and tolerance design in the aero-engine casing assembly.

A pump is a machine that imparts mechanical energy to a fluid flowing through it, to move it from one point to another. This paper reports the design, manufacture and testing of a centrifugal water pump having a circular casing. A single stage, end suction centrifugal pump designed and manufactured, using locally sourced materials. This pump finds application in homes, agriculture and industries. It consists of an impeller, shaft, suction and delivery pipes and an electric motor. Experiments performed with this pump shows that it can deliver 0.0045m3 of water per second with a pressure head of 34.7m. A 2.5kW electric motor running at a speed of 2900rpm was used to drive the pump.

Present study entitled was carried out in field irrigation lab, Department of Agricultural Engineering, Aditya Engineering College, Surampalem. In the present experiment locally available agricultural substrate paddy straw, sugarcane bagasse and cocopeat were tested with black soil and farm yard manner as casing materials. For parameters such as days required for spawn run, pinhead formation, harvest days, total yield and biological efficiency were determined. Significant results were obtained for all the experimental parameters and also for the stem length and cap diameter. Best substrate found was the paddy straw in the recent experiment with days required for spawn run (14 days), pin head formation (11.2 days), days for first harvest(50 days), stem length (8.07 cm), capdiameter (8.67 cm), first harvest (489.45 gm), second harvest (453.68 gm), total yield (925.24 gm), biological efficiency (94.31%). The next best in the order was coco peat followed by sugarcane bagasse. Hence this study confirms the suitability of paddy straw for cultivation to mushroom growers and farmyard manure with 15 cm casing thickness as substrate for its cultivation for achieving higher yield. The benefit cost ratio was estimated as 1.57.

Актуальность исследования обусловлена необходимостью предотвратить введение в прифильтровую зону объема породы с большей однородностью и большего размера по сравнению с крупной фракцией пластового песка - попытка добиться улучшения фильтрационных свойств прифильтровой зоны, т. е. снижения [zeta]2фк и [zeta]2n. Конструкция гравийной набивки одновременно должна исключать вынос частиц пласта в скважину. Решение этой проблемы позволит улучшить работу фильтрации пластовой жидкости из пласта в скважину и сократить затраты на дополнительное применение методов интенсификации притока пластовой жидкости к скважине. Цель: разработать методику, позволяющую при выборе конструкции фильтра, одновременно с возможностью обеспечения им надежной гидравлической связи в системе пласт-фильтр, предотвращать вынос песка в скважину. Объекты. Для предотвращения поступления песка из пласта и удержания гравия на забое скважины при создании гравийных набивок применяют щелевые, проволочные, кольцевые, титановые, металлокерамические и другие фильтры. Эти фильтры, установленные в интервале перфорации обсадной колонны без образования гравийной наружной кольцевой набивки (а именно таким образом в большинстве скважин устанавливаются фильтры на месторождениях России), очень часто забиваются пластовым песком, что приводит к снижению продуктивности скважин. Если для задержания песка используются щелевые фильтры, то эффективность их применения зависит от соответствия размера щелей гранулометрическому составу выносимого песка. Фильтры с ракушечной набивкой более эффективны, но также не всегда отвечают поставленной цели, поскольку прочность и качество ракушечника, закачиваемого в прискважинную часть пласта, довольно низкие. Кроме того, примененные на промыслах проволочные фильтры не имеют фиксации каждого витка, в результате чего при механическом повреждении одного из витков происходит срыв всей намотки. Методы. При применении предложенной методики полученные результаты экспериментальных работ по оценке способов снижения выноса песка из несцементированных неоднородных пластов показывают, что применение фильтров в обсаженном стволе требует создания гравийной набивки в кольцевом зазоре между фильтром и колонной, в перфорированном канале и за обсадной колонной. Причем размер гравия должен быть выбран таким, чтобы исключить перемешивание гравийной обсыпки с пластовым песком за счет миграции и интрузии песка, т. е. D/d=4-5. Снижения производительности скважин можно в этом случае избежать путем увеличения размера и количества перфорационных отверстий. Следует отметить, что предотвращение выноса песка означает, что при оптимальном установившемся режиме работы скважины фильтр удерживает частицы скелета пласта, но пропускает мелкодисперсные и глинистые частицы. В период запуска скважины картина несколько иная - пропускается и часть скелетообразующих частиц до того момента, пока на фильтрующей оболочке не образуется естественный фильтр из отсортированных крупных фракций. Результаты. Частицы, которые составляют структуру породы, не должны выносится из пласта за счет применения фильтра. Практически это означает, что фильтр должен не пропускать 75-85 % (по весу) более крупных фракций песка. Для сохранения общей устойчивости скелета пласта можно допустить вынос мелких частиц не более 15-25 % (во весу). The relevance of the study is caused by the need to prevent the introduction of a volume of rock with greater homogeneity and larger size into the near-filter zone compared to the coarse fraction of formation sand - an attempt to improve the filtration properties of the near-filter zone, i. e. decrease in [zeta]2фк and [zeta]2n. The design of the gravel pack should simultaneously exclude the removal of formation particles into the well. The solution to this problem will improve the work of filtration of formation fluid from the formation into the well and reduce the cost of additional application of methods for stimulating the inflow of formation fluid to the well. Purpose: to develop a methodology that allows, when choosing a filter design, simultaneously with the ability to provide them with a reliable hydraulic connection in the reservoir-filter system, preventing sand removal into the well. Objects. To prevent the flow of sand from the formation and retain gravel at the bottom of the well, when creating gravel packs, slot, wire, ring, titanium, cermet and other filters are used. These screens, installed in the casing perforation interval without the formation of gravel outer annular packing (and this is how screens are installed in most wells in Russian fields), are very often clogged with formation sand, which leads to a decrease in well productivity. If slot filters are used to retain sand, then the effectiveness of their application depends on the correspondence of the slot size to the granulometric composition of the sand being removed. Filters with shell packing are more effective, but they also do not always meet the set goal, since the strength and quality of shell rock pumped into the near-wellbore part of the formation are rather low. In addition, wire filters used in the fields do not have fixation of each turn, as a result of which, if one of the turns is mechanically damaged, the entire winding breaks down. Methods. When applying the proposed technique, the results of experimental work on evaluating ways to reduce sand production from unconsolidated heterogeneous formations show that the use of filters in a cased hole requires the creation of gravel packing in the annular gap between the filter and the string, in the perforated channel and behind the casing. Moreover, the size of the gravel should be chosen so as to exclude the mixing of the gravel packing with the formation sand due to the migration and intrusion of sand, i.e. D/d=4-5. A decrease in well productivity can in this case be avoided by increasing the size and number of perforations. It should be noted that sand avoidance means that under optimal steady state well operation, the filter retains formation backbone particles, but allows fines and clay particles to pass through. During the well start-up, the picture is somewhat different - part of the skeletal particles is also passed through until a natural filter of sorted coarse fractions is formed on the filtering casing. Results. The particles that make up the rock structure should not be carried out of the formation by applying a filter. In practice, this means that the filter should not pass 75-85 % (by weight) of the larger sand fractions. To maintain the overall stability of the formation skeleton, it is possible to allow the removal of small particles not more than 15-25 % (in weight).

In view of the geological characteristics of high pressure in salt-gypsum formation of deep wells in Tarim Piedmont structure, high-density oil-based drilling fluids are widely used, which makes it difficult for subsequent cementing work. In order to solve the technical difficulties of cementing high-density oil-based drilling fluid and salt-gypsum formation in KS well, which is a key exploration well in this area, through analysis of cementing technical problems, combined with salt-gypsum formation cementing and deep well ultra-deep well cementing technology, targeted measures before casing running, optimization of flushing aggravated isolating fluid and aggravating agent are carried out. In addition, relevant technical measures are put forward based on the optimization of cement slurry additives, the design of slurry formulation pipe string structure and the optimization of cementing technology. A set of flushing aggravating isolating fluid was prepared by introducing small particle size, concentrated superfine aggravating agent and hematite powder with relatively large particle size, and a set of high-density cement slurry with good comprehensive performance was obtained by optimizing cement slurry additives and introducing super high-density aggravating agent GM-1. In order to ensure the safety of cementing, the adaptability test of cement slurry formula was carried out, focusing on the adaptability test of cement slurry temperature and density: when the temperature changes + 5 °C the density increases + 0.03 g/cm3, the thickening time of the system changes less than 44 min, the system has good stability, and the anti-channeling performance of cement slurry SPN is less than 3, which has good anti-channeling function and meets the construction requirements, At the same time, the compatibility experiments of different proportions and different media and the simulated intermittent cementing experiments are added to meet the requirements. Field application of KS well shows that the technology can meet the cementing requirement of oil-based drilling fluid in Piedmont area.

Shear deformation often occurs during multistage fracturing of shale gas worldwide, increasing the operation cost of gas well completion and lowering the well’s productivity; strike-slip fault slippage is thought to be a crucial underlying factor. This paper presents a detailed analysis of the influence of strike-slip fault slippage on casing inner diameter and establishes a technique for predicting casing inner diameter after fault slippage. Numerical simulation models were developed to simulate the process of fault slippage and calculate changes in the inner diameters of the casing, considering different engineering and geological conditions. The influential factors, including the fault strike angle, slip distance, radius-thickness ratio, and mechanical properties of the formation, were analyzed in engineering practice; the simulation results were shown to be consistent. Four methods, including adjusting the wellbore trajectory of shale gas horizontal wells, avoiding perforation at the formation interface, decreasing the fracturing parameters including the fracturing pressure, discharge capacity, volume of injecting fracturing fluid, and prediction of casing inner diameter after casing shear deformation, were proposed and verified through engineering application and theoretical calculation, respectively.

Design of Radial Passive Magnetic Bearings with Active Dampers (Radial PMB-AD) and their application in a down-hole natural gas compressor (DHGC) are discussed. These compact and reliable bearings allowed non-contact suspension of a high-speed DHGC rotor spinning at 50kRPM in a highly adverse environment more than 3km (10,000 ft) below the ground with temperatures reaching 100 degrees C. The design was further complicated by the space limitations imposed by a well casing. The paper presents the design of PMB-AD modules, as well as their integration and testing as a part of a DHGC.

Short fillet welds used to fasten a large retainer ring to so-called dog bone seals failed in the turbine exhaust casing of a non-OEM heavy-duty gas turbine engine used for power generation. The subject fillet welds fractured due to high cycle fatigue loading. Neither weld imperfections nor any other material defects were found that could have contributed to the failure. It was concluded that an unfavorable design, specifying very short fillet welds for fastening the dog bone seal segments to the retainer ring, was the root cause of failure. In a purely static loading situation, this design would probably not have failed. However, in a dynamic loading scenario as is the case in any gas turbine engine exhaust, such a design is simply not sturdy enough.

Studies were conducted to evaluate leached sawdust as a casing substrate for the cultivation of Agaricus bisporus either alone or in combination with other substrates at College of Horticulture and Forestry, Neri, Hamirpur, Himachal Pradesh, India during the year 2018–2020. Out of seven casing media evaluated alone, coconut coir pith performed best in terms of all production parameters like time for spawn run (20.3 days) and pinning (15.7 days), sporocarps’ number (55.33), yield (0.679 kg 5 kg-1 compost) and biological efficiency (33.95%). The efficiency of sawdust- leached improved with the addition of other casing substrates. In commercial trial, combination of sawdust - leached with coconut coir pith, spent compost and farmyard manure (1:1v/v) performed better as compared to control (FYM+local soil), but a combination of sawdust- leached+coconut coir pith (1:1v/v) proved to be the best in terms of sporocarps’ number (88.00) and yield (1.271 kg 10 kg-1 compost) despite of the delay in time for spawn run (26 days) and pinning (24.3 days). Casing media also affected the biological efficiency of compost which varied from 10.50% in local soil to 34.05% in sawdust- leached+farmyard manure (1:1v/v) in different experiments. Cap diameter was recorded to be maximum (41.37 mm) in 2 years old spent compost and minimum (34. 27 mm) in sawdust- leached while, stipe length ranged from 14.17 mm in vermicompost-leached to 22.90 mm in sawdust- leached+farmyard manure (1:1v/v). However, fruit bodies harvested from all the casing treatments including standard check were found to be silky smooth and firm to compact.

One of the largest trap intrusion provinces, Siberian traps, is located in the East-Siberian Platform in Russia. A trap intrusion zone usually has abnormally low reservoir pressures and natural fractures. Consequently, trap drilling is associated with fluid losses that can be catastrophic. The section of trap intrusion is a part of a Ø 174 mm production casing section of the Srednebotuobinskoe field. The basic well design of this section also includes the Osinsky horizon, which features an abnormally high reservoir pressure zone. The latter creates incompatible with drilling conditions environment due to the presence of catastrophic loss zones in traps. Time spent on drilling a trap intrusion zone accounts for up to 30 % of the total well drilling time. The abovementioned geological issues in directional wells become the key topic in solving it. The method to resolve this issue is an integrated approach employing all the technologies and technical facilities aimed at finding a technological solution. First of all, in order to optimize the well construction cycles and reduce the complications, all the wells were classified in three categories as per the type of behavior in trap intrusion. This allowed to work out multi-level activities, that depended on severity of losses and non-operational time spent on drilling through this section. An alternative well design was developed and trialed on several wells, which showed positive results on decreasing non-productive timing. The main concept of this design was significantly different from the basic well design that was used in the past on the Srednebotuobinskoe field. The main difference was isolation of traps from the high pressure Osinsky horizon lower section with a Ø 245 mm casing string, which allowed safe splitting of two incompatible drilling zones. The economic effect of this solution allowed saving of up to 10.4 days or 15 % of the construction time in the wells of first category. These results were reviewed at the Technical Committee of the Company and agreed to implement the alternative well design on first category wells on the Srednebotuobinskoe field. In addition, for the rest of well categories the Drilling Team has produced and successfully implemented the preventative measures that allowed drilling through traps with lost circulation material. It is worth to mention that this method assumed a by-passing mud-cleaning system on the rig to allow building up a solid phase thus stemming the losses while drilling. For all the categories of the wells the Drilling team has selected and trialed different types and designs of drilling bits that would allow drilling hard rock such as dolerite section in traps with minimal number of runs. For the last five years the Drilling team together with the bit producing companies have designed a new type of PDC cutters that would allow to enhance durability as well as improve drilling speed both in dolerite formations and in overlying formations in the Production casing section. The Drilling team has also managed to reduce the number of trips associated with early bit wear decreasing them from five to two runs and create an experimental basis for drilling the entire section of the production casing in one run. From 2019 team continue looking for further solutions that would allow to improve bottomhole assembly elements balancing between durability and drilling rate in different types of formations above and below traps. A range of proposed technological solutions significantly reduced the impact on the well construction performance by preventing and reducing the downhole losses events in the section of trap intrusion on the Srednebotuobinskoe field.

The perforating technique is one of the well completion methods and a final stage that helps connect reservoir formation to wellbore during hydrocarbon production. The present work aimed to determine the effect of the perforated casing completion on the pressure gradient and perforation skin factor in the vertical near-wellbore region. This work presented a novel experimental approach for studying the effect of perforation parameters on hydrocarbon production by creating a prototype representing the near-wellbore region. The study conducted extensive laboratory testing to create two prototype artificial samples for a cylindrical near-wellbore region, open hole, and perforated casing sample. An experimental test was carried out using a geotechnical radial flow setup to measure the differential pressure in the two samples; the single-phase (water) was radially injected into the core sample within the same flow boundary conditions. Numerical simulation and statistical analysis were used to expand the investigation of the effect of the dimensions and distribution of perforations on the perforation skin factor and the pressure gradient in the cylindrical near-wellbore region. The results showed a clear view of the effect of the perforations’ parameters on the pressure gradient in the vertical near-wellbore region. In addition, two novel correlations were produced from statistical analysis that simplified the estimation of the perforation skin factor in the perforated casing completion. This study will help to clarify and understand the effect of perforation parameters on well productivity.

With the exploration of marine oil fields in deep and ultra-deepwater regions, the need for studying different methods of well construction has increased. Nowadays, the technique of laying conductive casing by jetting is the most widely used for the starting phase of a well in such conditions. In this scenario, in early layers, where the marine soil is in contact with seawater, this material can present itself as a fine mud, characterizing a cohesive non-drained soil, with low shear strength, being considered a material with viscoplastic behavior. Thus, as such, using fluid rheology to analyze it may represent a valid option; being possible to classify it as a Herschel-Bulkley fluid. The use of computational modeling and numerical simulation represent an alternative to understand the behavior of soil during jetting. In this context, this work focuses on developing a computational modeling of the jetting of marine soil, based on the soil fluid dynamics approach, using computational fluid dynamics (CFD - Computational Fluid Dynamics) software SIMULIA XFLOW, version 2020. This work aims to investigate the deformation in the seabed in response to an incident vertical jet using different drilling fluids, also modeled as viscoplastic materials. Drilling fluids suitable for jetting and a fluid with a higher specific mass were considered. For the proposed modeling of the soil and drilling fluids considered, the main parameters used were the yield point, consistency index, behavior index, and the boundary viscosity. The latter was necessary to implement the modified Herschel-Bulkley model used by the software. Results show that the excavated cavity presented a similar behavior for the drilling fluids suitable for jetting, indicating that the rheology of the drilling fluid does not interfere with the deformation of the soil. However, a significant influence on the profile of the excavated cavity was observed when implementing the drilling fluid of higher specific mass in the jetting, which deformed the soil at greater depths.

This paper aims to build a smart lighting system with applications such as remote for controlling power supply and optimizing heat management in the metal body of the semiconductor diode and with a printed circuit board for agriculture. The semiconductor diode strips with multiple colors are lined up and configured as a LED lamp with proper casing and heat sink. It has a driver circuit with required power regulation that is able to control the intensity of light for photosynthesis and plant growth requirements. The system uses hydroponics to plant the water, thus decreasing the usage of fertilizers. The entire system is controlled remotely using necessary communication interface application.

To effectively extract the information of compound faults of inter-shaft bearing of an aero-engine based on casing vibration signals, the paper has introduced the concept of weighted Katz fractal dimension and proposed the method combining information fusion, wavelet transform (WT), singular value decomposition (SVD), and Katz fractal dimension, the cross-correlation function (CCF-WT-SVD-Katz algorithm). The method includes homologous information fusion achieved by the CCF of horizontal and vertical vibration signals of the rotor from the same section; signal separation and denoising of blended signals through WT and SVD; reinforcement of fault characteristics of signals according to weighted Katz fractal dimension; and extraction of characteristic frequencies of compound faults of inter-shaft bearing by frequency spectrum of weighted and reconstructed signals. The result indicates that the proposed CCF-WT-SVD-Katz algorithm is capable of effectively extracting compound fault characteristics of inter-shaft bearing and precisely identifying a fault type based on whole casing vibration signals and will be of very good application value in engineering.

A fan-blade out (FBO) event may cause complex vibrations in an aeroengine. A fusing structure protects the structural integrity of the whole aeroengine after an extreme accident, such as a blade-loss event. In this paper, we investigate not only the transient and steady responses of a simulated aeroengine model with a fusing structure after an FBO event but also the changes made to the model because of the fusing structure. Our simulated model of an aeroengine includes two rotors, bearings, and a casing. The results for the dynamic response of the simulated model show that the fusing structure can reduce the steady-state response and the impact load on the support bearings in the rotor system. The rubbing impact between the blades and casing was accounted for. A fast method for calculating the response of fused structures was developed, which may be useful when designing the stiffness of the fusing structure.

Generally, geothermal fields in Indonesia are situated in the mountains, forests, and remote area. The surface area, access, environment, license, and permit are limited, so that from a permitted well pad many wells are designed directionally to reach the reservoir. Directional drilling in geothermal wells is challenging due to hard volcanic rocks, the presence of vugs or cavern, and high temperatures leading to massive lost circulation, drilling break, and the difficulty to turn and control the direction stably during drilling. These cause a critical condition reducing the wellbore quality: high Dogleg Severity (DLS), tight hole, and stuck pipe occurrence. Besides, this leads to higher stress and strain experienced by the casing or liner and causes yield strength reduction and failure. Thus, it is essential that the directional drilling design and operation, particularly trajectory, be optimized. This research summarized methods to evaluate the actual drilling operation and wellbore condition of wells in Dieng Field. The result is useful to identify the critical conditions caused by drilling and formation problems setting the maximum load limitations of the design and subsequent operation. It is recommended that buckling analysis, full-scale testing, and several design and operation scenarios be conducted prior to the drilling operation.

With the rapid development of shale gas exploration and development in China, casing deformation in shale gas horizontal wells happens frequently, which directly impacts the development efficiency and benefits of shale gas. In order to explore casing deformation prediction, prevention and treatment methods, this paper analyzes the geological and engineering causes of casing deformation in shale-gas horizontal wells through laboratory work, such as the casing resistance to internal pressure alternating test, the ground simulation test and systematical casing deformation characteristic analysis of MIT24 caliper logging, and the large-scale physical simulation test and numerical simulation of casing deformation. Then, combined with the generalized shear activity criterion, a new method for evaluating casing deformation risk points and some technical measures for preventing casing deformation were formulated. And the following research results were obtained. First, the deformation characteristics of 119 casing deformation points in 23 wells interpreted by MIT24 caliper logging are consistent with the mechanical behaviors of shear compression deformation test. Second, the large-scale physical simulation test shows that natural fault-fractures slip obviously under the state of strike-slip stress. Third, numerical simulation shows that the compression stress on casing increases with the increase of fault-fracture slip. When the fault-fracture slip is between 7.5 mm and 9.0 mm, the casing reaches the critical yield strength and begins to undergo plastic deformation. The “temporary fracture plugging + long segment and multi-cluster” and other technologies are field tested in 28 wells in Weiyuan area of southern Sichuan Basin. The casing deformation rate decreases from 54% (before this research) to 14.3%, and the segment loss rate decreases from 7.8% to 0, which reveals remarkable achievements in casing deformation treatment. In conclusion, the shear slip of fault and macro fractures (referred to as fault-fracture) is the main cause of casing deformation in shale gas horizontal wells, and some measures (e.g. “temporary fracture plugging + long segment and multi-cluster”, reducing fracturing scale and releasing wellbore pressure properly) shall be taken in advance to reduce the fault-fracture activity before the risk point of casing deformation is fractured, so as to reach the goal of casing deformation prevention.

Hydraulic fracturing has been widely used in the petroleum industry for exploiting tight and ultra-tight formations. Although conventional hydraulic fracturing techniques have advanced significantly over time, it is still challenging to achieve separate intervals within multilayered formations, target the right layers and accurately fracture in succession. Hydra-jet-assisted fracturing, which involves boosting pressure in the cavity behind the casing to enable successful fracture initiation, is a technique often practiced to overcome this. However, there exists limited research regarding the pressure field within the cavity; therefore, this study aims to establish a mathematical model for predicting boosting pressure in the cavity under various reservoir conditions. In this paper, the authors present a numerical model to investigate the effects of nozzle differential pressure ratio of nozzle diameter to cavity diameter, annulus pressure and cavity length on boosting pressure. It is observed that the boosting pressure increases linearly with nozzle differential pressure and diameter ratio, respectively, while retaining other parameters as constant. However, simulations also indicate that annulus pressure and cavity length have minimal effect on the boosting pressure. In addition, the relationship between the boosting pressure coefficient and dimensionless standoff distance is also developed for specific diameter ratios, along with an insightful sensitivity analyses. A mathematical model is established to predict the final boosting pressure at different diameter ratios. As a result, this advances understanding of the design of treatment parameters in hydra-jet-assisted fracturing. Furthermore, this investigation is another step forward toward the global application of hydra-jet fracturing technology in developing deeper and layered tight gas sands.

The autocorrelation function is combined with wavelet transform and cyclostationary theory (WT-AF-CT) in place of threshold denoising, and meanwhile the mean power ratio (MPR) is calculated by the proposed method. Furthermore, extracted characteristic as well as calculated MPR is used to identify compound faults of rolling bearings in aero-engine based on casing vibration acceleration signal-including the ones of common rolling bearing (inner race rotates and outer race is constant) and intershaft bearing (co-rotates with outer and inner race). A comparative analysis was carried out between conventional researches (cyclostationary theory (CT) or wavelet transform combined with threshold value denoising (WT-TD)) and proposed WT-AF-CT method. Additionally, the effect of sensors installation direction for feature separation and extraction of compound faults is considered. The results indicate that the proposed WT-AF-CT method can separate and extract characteristics of compound faults exactly and identify fault types of bearings precisely, no matter sensors are installed horizontally or vertically, while CT or WT cannot.

The analysis of works on identification of causes of deformation of casing production strings of wells is carried out. The main reason for the deformation of the strings is the technogenic deformation of the rocks of the layers of drained deposits. The need to take into account technogenic processes for the design of used wells at the design stage of oil and gas field development is shown.

In the modern turbo-machinery, reducing the clearance between the blade tip and casing inner face is an effective method to improve the power performance, but the clearance reduction leads to increased risk of blade-casing rubbing. In this paper, a blade-coating rubbing force model which considered the abradable coating scraping is developed to simulate the rotor system dynamic characteristics at blade-casing rubbing faults with abradable coating. An experimental tester is established to simulate the rotor system blade-casing rubbing faults; the AlSi-ployphenyl ester abradable coating is prepared and introduced into the blade-casing experiment to verify the model. After the vibration and force analysis in simulation and experiment, the dynamic characteristics and the influence factors of blade-casing rubbing rotor system are studied.

In the petroleum industry, packers refer to the components/products which are used to isolate one section in a formation from others, or to isolate the outer section of a production tubing from the inner section, which may be a casing or a liner or the wellbore itself. Mechanical packers are installed through some form of tubing movement. Permanent packers are low in cost and provide better seal. Retrievable packers have lower sealing capability but are re-usable after repair, and therefore expensive. More innovative packers made of swellable elastomers are rather new. These elastomers swell when they come in contact with different types of fluids (mostly water and oil). Like a casing, these new packers are lowered to the desired depth and allowed to swell before production or injection operations begin. Various studies have been published about the swelling and mechanical response of these elastomers. However, many questions remain about the sealing performance of swell packers, and their effectiveness in actual wellbores of rough and random profiles. This paper describes the design and development of an experimental unit for performance testing of a mix of inert and swelling elastomer seals under realistic well conditions. Actual swell packers and petroleum tubulars are housed in a concrete block that replicates open-hole and cased-hole wells through layers of varying roughness. This is a one-of-its-kind unit providing full-scale demonstration about the working of swell packers against outer casing or rock formation in a wellbore. It is also a complete testing apparatus to investigate the behavior of swell packers made of fast-swell and medium-swell elastomers, and how they seal off irregular boreholes. This work can provide basic understanding and visual corroboration to petroleum engineers and students, swelling elastomer application developers, and academic and research personnel.

With the rapid development of aero-engine manufacturing technology, the dual-rotor system has been employed in part of turbofan engine in order to improve the working performance of aircraft more efficiently. In this study, taking the counter-rotation dual-rotor as the research object, the dynamic model of dual rotor-casing coupling system is established by the aid of MATLAB. The dynamic frequency curves are in good agreement with the results in references and calculated by FEM method, that shows the validity and feasibility of the model. The local rub-impact dynamic model of dual rotor-casing coupling system is established, and rubbing analysis is carried out using Newmark- β method. The effects of rotating speed and speed ratio on local rub-impact response are deeply discussed. The results show that with the increase of rotating speed, combined frequencies and frequency multiplication components are more significant. In addition, speed ratio has a great influence on the periodic motion of the system. With the increase of the absolute value of the speed ratio, the whirl radius of the outer rotor and the normal rubbing force increase dramatically.

Multistage fracturing is the main means of shale gas development, and casing deformation frequently occurs during fracturing of shale gas horizontal wells. Fracturing fluid entering the formation will change in situ stress nearby the wellbore. The changes of in situ stress are mainly reflected in the following two aspects: one is the increase of in situ stress and the other is the nonuniformity of in situ stress along the wellbore. And it is for this reason that the production casing is more likely to collapse under the nonuniform in situ stress load. According to the service conditions of production casing in shale gas reservoir, this paper studied the casing deformation and the collapsing strength subjected to the nonuniform loading by the experimental and numerical simulation method. The results show that under the condition of nonuniform loading, (1) the diameter variation rate of the casing reduces with the increase in the ratio of sample to tooling length. When the ratio is less than 3, the casing collapse strength will be significantly reduced. And when the ratio is greater than 6, the impact of sample length on casing collapse strength can be ignored. (2) The increase in the applied loading angle will decrease the diameter variation rate. When the loading angle increases from 0° to 90°, the critical load value increases from 1600 kN to 4000 kN. (3) The increase in load unevenness coefficient will rapidly decrease the casing collapse strength. When the load unevenness coefficient n is 0.8, the casing collapse strength reduces to 60%, and when the load unevenness coefficient n is 0, the casing collapse strength reduces to 28%. The findings of this study can help for better understanding of casing damage mechanism in volume fracturing of shale gas horizontal well and guide the selection of multistage fracturing casing type and fracturing interval design.

Losses induced by tip clearance limit decisive improvements in the system efficiency and aerodynamic operational stability of aero-engine axial compressors. The tendency towards even lower blade heights to compensate for higher fluid densities aggravates their influence. Generally, it is emphasised that the tip clearance should be minimised but remain large enough to prevent collisions between the blade tip and the casing throughout the entire mission. The present work concentrates on the development of a preliminary aero-engine axial compressor casing design methodology involving meta-modelling techniques. Previous research work at the Institute for Turbomachinery and Flight Propulsion resulted in a Two-Dimensional (2D) axisymmetric finite element model for a generic multi-stage high-pressure axial compressor casing. Subsequent sensitivity studies led to the identification of significant parameters that are important for fine-tuning the tip clearance via specific flange design. This work is devoted to an exploration of the potential of surrogate modelling in preliminary compressor casing design with respect to rapid tip clearance assessments and its corresponding precision in comparison with finite element results. Reputed as data-driven mathematical approximation models and conceived for inexpensive numerical simulation result reproduction, surrogate models show even greater capacity when linked with extensive design space exploration and optimisation algorithms.Compared with high-fidelity finite element simulations, the reductions obtained in computational time when using surrogate models amount to 99.9%. Validated via statistical methods and dependent on the size of the training database, the precision of surrogate models can reach down to the range of manufacturing tolerances. Subsequent inclusion of such surrogate models in a parametric optimisation process for tip clearance minimisation rapidly returned adaptions of the geometric design variables.

This paper considers effects of Rotating Inlet Distortion (RID) on a two-stage axial compressor and the stabilization effects of a casing treatment subjected to the considered RID. In multi-spool engines, the downstream compressor suffers a RID when the upstream fan/compressor is in rotating stall. A controlled rotating sectional screen upstream of the compressor was adopted to generate the RID in different intensities, and co- or counter spinning direction compared with the rotor. The response of the compressor to inlet distortion was interpreted as the changes of stall margin. Results show that there are two peaks for the stall margin degradation where the distortion screen rotates near 20% and 70% of the rotor’s rotational frequency, respectively. Based on the measurements taken during the pre-stall process, it is suggested that the two frequencies are associated with the eigen frequencies of the compressor. Specifically, the first is associated with a stall precursor that is suspected as an initial disturbance existing in compressor and the second is related to a spike-type stall precursor. At last, a kind of Stall Precursor-Suppressed (SPS) casing treatment was applied to enhance the compressor stability in RID conditions. The result indicates that the stall margin is improved by 6% at an average level and there is nearly no efficiency loss caused by the application of such casing treatment.

The detonation of an energetic material (EM) is manifested in the form of blast wave, fragmentation of casing material, and thermal effects. These effects are very destructive and cause injuries-being fatal-and structural damage as well. The attenuation of these effects is a prime focus. C4 explosive weighing 104 g was tested as surface burst. Peak overpressures of 1362 kPa and fireball radius of 0.65 m were measured. A multi-layer container comprised steel liner, Kevlar woven fabric, and laminated glass fiber reinforced polymer (GFRP) was developed and investigated to counter the combined blast, fragmentation, and thermal effects of EM detonation. Commercially available shaving foam was characterized and used as filling material inside the container. The foam bubbles have shown a good stability with time. The shaving foam quenched the fireball and afterburning reactions owing to rapid heat and momentum transfer mechanism. The containment system provided more than 80% overpressure reduction with respect to an equivalent open-air detonation and also restricted any escape to lateral directions. Coupled Euler-ALE (Arbitrary Lagrangian-Eulerian) approach was employed to numerically simulate the blast wave parameters. A good agreement is obtained between the simulation and experimental results.

Modern low-pressure turbine engines are equipped with casings impingement cooling systems. Those systems (called Active Clearance Control) are composed of an array of air nozzles, which are directed to strike turbine casing to absorb generated heat. As a result, the casing starts to shrink, reducing the radial gap between the sealing and rotating tip of the blade. Cooling air is delivered to the nozzles through distribution channels and collector boxes, which are connected to the main air supply duct. The application of low-pressure turbine cooling systems increases its efficiency and reduces engine fuel consumption.

This work is performed to improve or strengthen the soil in the permafrost region under building foundations or engineering structures in the conditions of the Far North. Freezing in winter and partial thawing in summer of the surface layer of permafrost are analyzed. According to the surveys on soil temperature, thawing of permafrost soils is predicted. Promising solutions are considered for the permafrost soil stabilization. The latest design solutions and developments are presented for the creation of many systems and devices for thermal stabilization of permafrost soils. A schematic diagram is suggested for the experimental installation for recording changes in ambient air temperatures and permafrost. The equipment is selected for studying the automated control system for the cooling process of casing pipe of the foundation pile and near-pile permafrost soil. An experimental installation is proposed to study the effectiveness of the automated control system. The model and simulation of this system is imple- mented in the SimInTech program. The automatic control system provides control for thermoelectric modules in automatic mode in order provide their best orientation in the ambient air temperature, depending on the soil temperature in the near-pile space of the foundation. A device is patented for stabilizing the frozen ground of a pile foundation with casing pipes containing a system for automated control for cooling process of the near-pile foundation.

In empty well killing, in order to save the time and cost of killing the well, the dynamic replacement method is often used to kill the well. The main problem of the dynamic replacement method for killing wells is how to avoid terrible working conditions caused by flooding, such as gas carrying fluid, killing fluid being brought to the wellhead. Based on the principle of flooding formation and the basic tenets of flooding correlation experiment and dynamic replacement method, this paper incorporates the kill fluid viscosity, surface tension, droplet diameter, inclination angle, drill pipe joint outer diameter, and drill pipe eccentricity into the calculation range and establishes a new mathematical model suitable for dynamic replacement kill. Based on the calculation results, the influencing factors of flooding are analyzed, and the following conclusions are drawn: the increase of dynamic viscosity, gas density in the well, casing pressure, well angle, the outside diameter of drill pipe, the outer diameter of drill pipe joint, and eccentricity of drill pipe can promote the occurrence of flooding; The increase of surface tension, well-killing fluid density, and casing inner diameter have an obstacle to flooding.

The first stage of GE-E3 turbine is employed to investigate effect of casing purge flow upstream rotor blade tip. Three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations and standard k-ω model are solved to obtain tip heat transfer simulations. The results reveal that: heat transfer coefficient of blade tip surface can be significantly reduced when casing purge flow is set. Tip averaged heat transfer coefficient of cases with and without swirly velocity casing purge flow decrease 3.5% and 3.4% compared with the case without casing purge flow. Compared with case which blowing ratio equals to 0.5, it can be found that averaged tip heat transfer coefficient of cases which blowing ratio equals to 1.0 and 1.5 decrease 2.3% and 1.8%, respectively. Setting blowing ratio as 1.0 can best cool tip surface without wasting cold air resources. Increasing rotating speed can induce cold air entering tip trailing region and improve local cooling effect. Flow structure inside the tip clearance are also revealed and discussed.