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This paper develops a simulation-based model to derive critical maintenance parameters towards optimizing a deep drilling rig availability and maintenance costs. Full factorial analysis is performed to derive the effects and interactions of the derived parameters, based on which ones with a significant effect on the availability and maintenance cost are selected. The case study based model incorporates maintenance, spares and workforce strategies for a geothermal drilling rig. The results offer essential maintenance decision support to both the management and maintenance team of the company and have the potential of further offering insights that eventually reduce the cost of drilling.

The deeply eroded Acraman structure in the Mesoproterozoic Gawler Range Volcanics, Gawler Craton, South Australia, ranks among the world’s largest known impact structures, with a transient crater ∼...

The main task of the research was to analyze of the hydrocarbons carboniferous objects of the axial and southern slope zones of the DDD with the aim of predicting further geological prospecting works. Based on the results of the research, promising objects have been identified that determine further areas of prospecting and exploration in the perspective deposits of the Lower and Upper Carboniferous in the study area of the region.It was revealed that among the Paleozoic productive and promising complexes in the axial and southern slope zones of the DDD, on number of identified and prepared objects and their resource base, a priority complex is Carboniferous. The primary objects in that complex are Borzakovska, Brusivska, Uspenovska, Osterska and Rozdolevska structures. We are associate the priority direction of prospecting works in combined traps with anticlinal and non-anticlinal complicated structures in the Lower Carboniferous deposits with those structures. Author is proposing to carry out priority detailed seismic exploration work on the Gersenvanovskaya and Topoleva identified structures to prepare them for prospecting drilling.It has been established that the second place (after the Lower Carboniferous complex) in terms of priority and prospectively is Medium Carboniferous deposits, in which within the study area on primary importance on the searching for hydrocarbon deposits are prepared Dovgopolivska, Svyatogirska, Stepnovska, Eastern-Shebelinska and other structures. In addition, Krasnoglazovsky and Western-Ukrainian promising objects are recommended for preparation by seismic exploration for drilling.It has been proven that in the Upper Carboniferous - Lower Permian deposits, where more than half of the proven gas reserves are located. The further prospects should be associated only with the zones and blocks near salt bunch. Most perspective for hydrocarbon searching in sediments C3+P1 is Yuzhnorozpashnovsky and Severnozhkovsky objects. Western-Ukrainian object, Verkhnelannovsky northern and southern blocks and Onezshska structure are required seismic survey preparation for drilling.Due to reason, that priority structures for further exploration are located, in most, in the axial zone of the region, the main concentration of prospecting works should be carry out within that zone, not taking into account the existing depths of objects. Within the southern slope zone at shallower depths, Brusivskaya, Ostersky and Uspensky structures are prepared for drilling. The implementation of prospecting and geophysical work on the recommended objects of the studied territory of the DDD will be allow to identify new hydrocarbon deposits and replenish the fund of promising objects, that prepared for deep drilling.

In order to enhance the understanding of the planet's geological evolution and determine whether there exists liquid water, solid ice or any other life evidence, plenty of extraterrestrial explorations have been attempted over the past decades. For future planetary drilling missions, especially unmanned drilling tasks, the autonomous drilling activity should be first verified. In order to replicate the geological formations encountered in the lunar drilling process, large amounts of lunar soil simulant are required. This simulant must be prepared at controlled densities in order to mimic the true mechanical behavior of real lunar soils. Herein, a tamping based dense soil simulant preparation method is proposed. Taking hammer's rebounding, soil's plastic-elastic deformation, and simulant's effective dense height into consideration, a novel theoretical tamping model has been established to predict the preparation parameters. Verification tests showed that the theoretical model correctly predicts the experimentally observed trend in the tamping force with the number of cycles and the optimized relative density of simulant over 180 mm depth from the top is close to that of the real deep lunar soil.

This article presents a new practical approach to gain a better insight into the machinability enhancements of ultrasonic-assisted drilling (UAD) of aluminum alloys where the depth ratio is...

Deep drilling operations are primarily used to produce oil, gas, and geothermal heat from reservoirs in the earth’s crust. A drill string built of thread-connected components is used to transfer mechanical energy from a drill rig on the surface to a drill bit at the bottom end. The lowest part of a drill string, which is called bottom-hole assembly (BHA), contains sophisticated sub-assemblies for process and trajectory control, formation evaluation, surface communication, power generation, and system diagnostics. The BHA can experience critical vibrations without indication further up to the string. These vibrations need to be closely monitored for process control, fatigue management, and design feedback. However, the number of sensors is too small to provide reliable indication of loads on all critical components of the drill string. Adding sensors to each component is currently neither economically nor technically viable. This paper presents an application of existing Kalman Filters, merging information from available sensors and dynamic models to obtain state estimates for all components of the BHA. The expected accuracy and limitations are discussed. The results of load extrapolation are confirmed by comparison with measurements proving the concept under inaccurately defined interaction with a downhole environment.

Barite sag is a challenging phenomenon encountered in deep drilling with barite-weighted fluids and associated with fluid stability. It can take place in vertical and directional wells, whether in dynamic or static conditions. In this study, an anti-sagging urea-based additive was evaluated to enhance fluid stability and prevent solids sag in water-based fluids to be used in drilling, completion, and workover operations. A barite-weighted drilling fluid, with a density of 15 ppg, was used with the main drilling fluid additives. The ratio of the urea-based additive was varied in the range 0.25&ndash, 3.0 vol.% of the total base fluid. The impact of this anti-sagging agent on the sag tendency was evaluated at 250 &deg, F using vertical and inclined sag tests. The optimum concentration of the anti-sagging agent was determined for both vertical and inclined wells. The effect of the urea-additive on the drilling fluid rheology was investigated at low and high temperatures (80 &deg, F and 250 &deg, F). Furthermore, the impact of the urea-additive on the filtration performance of the drilling fluid was studied at 250 &deg, F. Adding the urea-additive to the drilling fluid improved the stability of the drilling fluid, as indicated by a reduction in the sag factor. The optimum concentration of this additive was found to be 0.5&ndash, 1.0 vol.% of the base fluid. This concentration was enough to prevent barite sag in both vertical and inclined conditions at 250 &deg, F, with a sag factor of around 0.5. For the optimum concentration, the yield point and gel strength (after 10 s) were improved by around 50% and 45%, respectively, while both the plastic viscosity and gel strength (after 10 min) were maintained at the desired levels. Moreover, the anti-sagging agent has no impact on drilling fluid density, pH, or filtration performance.

The most important raw materials for different industries are oil and natural gas. With increasing consumption, the demand for drilling and the quality of production increases. Therefore, the exploration and production of hydrocarbons requires not only first-class machinery and technological equipment, but also qualified personnel. Exploration and drilling, production of hydrocarbons, like any other industry, cannot avoid accidents, emergen-cies and catastrophes. The worst type of well accident is undoubtedly an open eruption of the extracted crude oil. Open eruption can lead to serious injuries to the rig personnel, damage and destruction of equipment, negative environmental impact and loss of crude oil. Exploratory drilling can cause the rise of pressure and its subsequent manifestations. During the first deep drill-ing, there may not be enough information about the drilled horizons. If the reservoir pressure in the production horizon is higher than the hydrostatic pressure of the fluid in the well (for example, drilling mud), the formation fluids flow into the well and move towards the surface, which causes open eruption. The rig personnel must be properly trained to be able to recognize the occurrence of rising pressure by various signs and to respond effectively to the situation. Some-times, under the influence of the human factor or equipment failure, open eruption still occurs. The article discusses the possibilities of eliminating open eruptions with drilling tools.

The important scientific questions that will form the basis of a full proposal to drill a deep well to the ductile–brittle transition zone (T>400 ∘C) at Newberry Volcano, central Oregon state, USA, were discussed during an International Continental Drilling Program (ICDP) sponsored workshop held at the Oregon State University-Cascades campus in Bend, Oregon, from 10 to 13 September 2017. Newberry Volcano is one of the largest geothermal heat reservoirs in the USA and has been extensively studied for the last 40 years. The Newberry Deep Drilling Project (NDDP) will be located at an idle geothermal exploration well, NWG 46-16, drilled in 2008, 3500 m deep and 340–374 ∘C at bottom, which will be deepened another 1000 to 1300 m to reach 500 ∘C. The workshop concluded by setting ambitious goals for the NDDP: (1) test the enhanced geothermal system (EGS) above the critical point of water, (2) collect samples of rocks within the brittle–ductile transition, (3) investigate volcanic hazards, (4) study magmatic geomechanics, (5) calibrate geophysical imaging techniques, and (6) test technology for drilling, well completion, and geophysical monitoring in a very high-temperature environment. Based on these recommendations, a full drilling proposal was submitted in January 2018 to the ICDP for deepening an existing well. The next steps will be to continue building a team with project, technology, and investment partners to make the NDDP a reality.

One of the key priority tasks for the international Antarctic community is drilling and studying old Antarctic ice with age exceeding 1 million years in order to investigate possible reasons for the Mid-Pleistocene Transition. During the 2017–2018 austral season at Vostok Station, we carried out microscopic study of geometrical properties of the crystalline inclusions of air hydrates in ice core samples from boreholes 5G‑3 (Vostok) and DC2 (EPICA DC) in depth intervals where the age of the ice exceeded 400,000 years. The obtained data confirmed the existence of a robust linear relationship between the mean radius of the hydrates and the age of the ice in the bottom part of the East Antarctic ice sheet, and will be useful for further development of the new dating technique based on the phenomena of hydrate growth in polar ice. Preliminary, the age of the atmospheric ice bedded at Vostok at a depth of3538 m, inferred from the data on the size of the hydrates, amounts to 1.3±0.17 million years. The existence of ice older than 1 million years in the vicinity of Vostok implies that in the area of Ridge B, where the ice flow line which passes through Vostok Station originates, even older ice, with undisturbed stratigraphy, may exist. It would be desirable therefore to carry out a glacio-geophysical traverse to Ridge B in order to implement a detailed study of Dome B area aimed at identifying the most suitable site for a new deep drilling of the Antarctic ice sheet.

Supercritical geothermal development method has been proposed to increase the use of geothermal resources; the associated challenges include high temperatures and pressures, as well as an acidic environment, which increase the corrosion rate of casing materials. Here, we estimated material corrosion rates assuming that the temperature and pressure in a developmental environment were 500 °C and 60 MPa, respectively. Wells WD-1a in the Kakkonda geothermal field, Japan, and Icelandic Deep Drilling Program-1 (IDDP-1) were used as model cases for the concentrations of volcanic gasses. Geochemical calculations were conducted to obtain distributions of pH values from room temperature to 500 °C at 60 MPa. Corrosion rate distributions for the metallic materials were derived for the temperature recovery period after drilling and production and post-production periods inside the well. Consequently, the pH remained approximately constant at temperatures ≤ 300 °C and increased as the temperature exceeded 300 °C. In the supercritical temperature and pressure region, the pH increased as the pressure decreased, and it maximized at a 0.35 g/cm3 fluid density. The IDDP-1 model exhibited lower pH values than the WD-1a model; the H2S/CO2 ratio and HCl gas also increased. Furthermore, from room temperature to 300 °C, the corrosion rates were found to increase with the temperature and maximized in the subcritical regions at 300–350 °C. The corrosion rates then decreased as the temperature increased in the supercritical temperature regions. In the possible developmental processes, the corrosion rates tended to be high at temperature of 300–350 °C (~2,000 m) during the temperature recovery period after drilling, whereas the corrosion rates tended to increase near the wellhead during fluid production. The corrosion rate maximized near the wellhead immediately after the production period ceased at a well depth of 1,000–1,500 m the following week.

To achieve safety, high quality, and efficiency in deep drilling, it is necessary to get formation drillability around the borehole during drilling-trajectory planning and intelligent drilling control. Since the drilling data have the characteristics of low value density and noise in the process of deep drilling, it is difficult to model formation drillability in deep drilling. In this paper, a new online modeling method for formation drillability based on online sequential nadaboost extreme learning machine (OS-Nadaboost-ELM) algorithm has been proposed. Firstly, the well logging parameters are chosen as the inputs of the model, whose output is formation drillability. Then, several ELM models are established and the outputs of these models are as weak learners. Then the weak learners are combined by Nadaboost algorithm in order to get a strong learner. Finally, the recursive least squares algorithm is used to adjust the model. The numerical test results show that, in both prediction accuracy and training efficiency aspects, the proposed method is better than other prediction methods such as multiple regression, gray method, back-propagation neural networks, Nadaboost extreme learning machine and online sequential extreme learning machine. Thus the prediction model serves as the online geological model to develop intelligent drilling systems.

Water properties change with confinement within nanofilms trapped between natural charged clay particles. We investigated nanofilm characteristics through high-stress laboratory compression tests in combination with analyses of expelled pore fluids. We utilized sediments obtained from deep drilling of the Nankai subduction zone at Site C0002 of the Integrated Ocean Drilling Program (IODP). We show that below 1–2 km, there should be widespread ultrafiltration of migrating fluids. Experiments to > ∼ 100 MPa normal compression collapse pores below a few ion monofilm thicknesses. A reduction towards a single condensing/dehydrating ion monofilm occurs as stresses rise >100–200 MPa and clay separations are reduced to

International audience; The aim of the Iceland Deep Drilling Project is to drill into supercritical geothermal systems and examine their economic potential. The exploratory well IDDP-2 was drilled in the Reykjanes geothermal field in SW Iceland, on the landward extension of the Mid-Atlantic Ridge. The Reykjanes geothermal field produces from a

Summary Acoustic Emission (AE) based systems have been under development and used at Fraunhofer IEG to monitor, evaluate, and control conventional and novel drilling processes and their pertinent equipment used in geothermal and drilling applications. Moreover, novel jetting and drilling operations in deep geothermal reservoirs do heavily rely on such new technologies in order to be able to control them properly and thus, to result in a viable technical and economical option. AE monitoring is based on the detection and conversion of elastic waves into electrical signals, which are associated with a rapid release of localized stress-energy propagating within a material. It is passive testing, logging, and analysis method to evaluate changes in the properties and behavior of machines and mineral type materials such as rocks. Such changes may be induced by drilling, jetting, or other drilling methods and being recorded, characterized, and evaluated via an AE system and will be used ultimately used for process performance prediction using machine learning methods. This is the core of the novel monitoring system development, the AE based, so-called Multi-Sensor acoustic parameter analysis as the primary control and monitoring mechanism during rock breaking, drilling, jetting, and stimulation.

This paper presents magnetic-field-assisted femtosecond laser drilling of bone with deep drilling depth, good surface quality and high removal rate. In this study, the feasibility of producing deep cavity under magnetic field condition is investigated. When magnetic field is introduced, the depth of drilling hole is increased from 236μm to 483μm, and the removal rate is increased from 3.04×10-3 mm3/s to 5.46×10-3 mm3/s. Moreover, no thermal damage including carbonization is observed during laser drilling process.

Summary This paper considers the effect of an antistall tool on the dynamics of deep drilling systems. Field results show that the antistall tool increased the rate of penetration (ROP) of drilling systems when compared with ROP in offset wells drilled without this tool. We developed a model–based approach to investigate the effect of this downhole tool on the ROP and on the mechanical specific energy. Toward this, a drillstring model including the antistall tool was constructed; it describes the coupled axial/torsional dynamics in the form of delay differential equations. Simulation results and a dynamic analysis based on averaging the obtained steady–state response show that an increased drilling efficiency was obtained using the antistall tool, resulting in a higher ROP.

Attempts to interpret the origin of seismic boundaries in the crystalline crust in the Fennoscandian Shield from deep drilling records and available geological and geophysical data were made by a number of authors. This article contains an overview of the most essential results reported so far. Deep drilling was conducted in several regions of the Fennoscandian Shield: Kola, Russia (SG-3), to a depth of 12,262 m (1970–1990); Gravberg (GR) and Stenberg-I, Central Sweden, to a depth of 6337 m (1986–1987); and 6529 m (1991–1992); Outokumpu (OU), SE Finland, to a depth of 2516 m (2004–2005); Pogranichnaya (P-1), Sredny Peninsula, Murmansk Region, Russia, to a depth of 5200 m (2004–2006); and Onega, Central Karelia, Russia (ON), to a depth of 3537 m (2007–2008). The results obtained were analyzed. They show considerable discrepancies between forecast seismic-geological models and the actual structure of the upper portion of the continental crust. Deep drilling has proved that heterogeneities in the upper portion of the crystalline crust, indicated by geophysical data, are due to changes in the composition and physical conditions of deep-seated rocks. Therefore, even approximate rock composition cannot be uniquely estimated from elastic wave velocities alone. Deep drilling showed the real pattern and origin of low-velocity zones in the upper portion of the crust and did not show that layers become more homogeneous with depth. The origin of intra-crustal seismic boundaries could be associated with various factors, such as variations in mineralogical composition, structural and textural differences between the rocks, and a thermodynamic setting.

Examples are presented to illustrate the high-speed drilling of small-diameter holes (up to 10 mm) by core flat drills: holes (diameter 7 mm) in a discharge valve; and the drilling two-part holes consisting of a cylindrical section (diameter 3.8 mm) and conical section (base diameter 10 mm) in a metal housing.

Round trip activity occurs discretely due to the abrasion of drill bit in the deep drilling project. Round trip has great impact on the drilling performance because it takes more time to change a drill bit as the depth goes deeper. Therefore, a reliable prediction technology of the round trip should be secured for feasibility analysis and effective management of the drilling project. Lee et al. (2013) developed the TOSA (round trip occurrence simulation algorithm) which can analyze the depth and timing of round trip occurrence at each abrasion state of bit. However, TOSA has weakness that it takes long time for simulation because the number of simulation increase exponentially as increasing the number of simulation section. This study developed the TOSA based round trip performance prediction module using genetic algorithm for simulating in a short time and verified simulation results.

We present here a brief description of the drilling operations in the deep 5G hole at the Russian Vostok Station with more detailed account of the final stage of this long-term project successfully ended on February 5, 2012 with the first Lake Vostok unsealing. Relevant information on the borehole design and the technical characteristics of the downhole and surface drilling equipment is given. The peculiarities of the drilling process are discussed in connection with changing properties of the penetrated ice. The data analysis allows defining the main factors that influence the efficiency of the electromechanical drill system at great depths. It is shown that the elevated temperature of ice and its coarse-crystalline texture are mainly responsible for the significant for the showing-down of ice coring in the bottom sections of ice sheets observed at Vostok and at other drilling sites in Antarctica and Greenland as well. Based on the large amount of experimental data obtained in the course of the deep drilling at Vostok, we discuss the processes which occur in the borehole during the ice drilling and unsealing the sub-ice water bodies. In particular, we investigate the conditions for occurrence of hydraulic fracturing in the hole and the possible effect of the hydrofrac on the height of the water column that have risen in hole 5G after the Lake Vostok unsealing. Finally we formulate the drill equipment requirements and process specifications that would ensure the best performance of an electromechanical drill and trouble-free drilling operations at different depths in a borehole up to the bottom of ice sheet.

Summary The modern geological model of the Kovykta gas condensate field is based on drilling more than 70 deep wells and 2D seismic surveys. In the course of carrying out high-density 3D seismic studies, transient electromagnetic soundings in the near field zone (TEM), deep drilling and geophysical well logging, the geological model undergoes adjustments. The paper shows the results of modern geophysical studies and drilling within the Kovykta gas condensate field, as well as their geological interpretation.

The article describes the details of a super deep drilling project developed in the USSR in the late s The program of work outlined the development of a model of the structure of the earth s crust as well as new methods for forecasting mineral deposits In total wells with a depth of km were drilled the deepest of which was the Kola well with a record depth of m

Worldwide, many research groups have been dealing with several innovative drilling technologies. Their common aim is to significantly decrease the overall price of the drilling process, particularly to keep the high constant speed, energy efficiency and shorter drilling time. The vision of geothermal energy, as the clean energy of the future, is currently one of the most driving challenge for development of new deep-drilling technologies. This paper presents one of such activities — development of novel technology based on electrical plasma for hard rock drilling. During this development, another application was identified as well — milling of steel casing and cement for well plug & abandonment operations.

In search for the root cause of stick–slip, a mode of torsional vibrations of a drilling assembly, a linear stability analysis of coupled axial–torsional vibrations has been carried out. It has been shown that in a rotary drilling system with axial and torsional degree of freedom two distinct modes of self-excited vibrations are present: axial and torsional. These axial (torsional) modes of vibrations are due to resonance between the cutting forces acting at the bit and the axial (torsional) natural modes of drillstring vibrations. It has been demonstrated that although axial and torsional modes of vibrations do affect each other the underlying mechanisms driving these modes of vibrations are completely different. In particular, the only driving mechanism of the axial vibrations is the regenerative effect, while there are two distinct mechanisms that drive the torsional vibrations: (i) the cutting action of the bit, and (ii) the wearflat/rock interaction. Moreover, in the case of the torsional vibrations the regenerative effect plays only a secondary role. The results of the present study indicate that the axial compliance can play a stabilizing role. In particular, the stabilizing role of the axial compliance increases as the ratio of the torsional to the axial natural frequency of the drillstring vibrations decreases.

Parameter identification of the mathematical model of spiral-drill wear in deep drilling is considered. Wear is simulated by piecewise-linear approximation of the growth of drag torque in drilling. The diagnostic index selected is the constant component of the drag torque after the onset of drilling. The significance of the diagnostic index in determining the wear is demonstrated.

According to the characteristics of wire-line coring drilling technology and combined the project of ZK3 borehole in salt exploration in Ye-wu sag in Henan province, the data of construction cost and efficiency for wire-line coring and roundtrip coring separately have been analyzed. In a certain evaluation period, the technical and economic evaluation for wire-line coring and simulation roundtrip coring in ZK3 borehole conducted by net present value (NPV) method, the result shows that, in ZK3 borehole, comparing with roundtrip coring, the drilling efficiency of wire-line coring method improved by 85%, the profit is 6.3 times than roundtrip coring, its technical economy is more obvious along with the depth increase. The sensibility analysis shows, the most sensitivity factors effecting on the borehole efficiency are construction price and construction period.

Particularly important is the use of drilling fluid in carrying out drilling works to great depths and especially in difficult geological conditions. Proper function of the drilling fluid is governed by the selection of their physico-chemical properties. Drilling works of hydrogeological survey require circulation of borehole with such rinses, which at a minimum pollute water-bearing horizons and their chemical composition meets hygiene requirements.

The aluminum alloy drill rod has light weight, high specific strength, more deep drilling depth and so on. The development and application of aluminum alloy drill rod has a great practical significance for improving geological drilling efficiency at where it is hard to enter and promoting scientific drilling technological progress and reducing the energy consumption. In this paper, the current situation and key technology of batch and serialization for aluminum alloy rod were introduced, and its application technology characteristics, trial production key technology, indoor experiment, and application situation had been analyzed. The research about aluminum alloy rod for high temperature was suggested after reviewing the foreign research results.

Preparation has begun for drilling the second deep IDDP well into the saline Reykjanes high-temperature field in SW-Iceland. The site selection for the IDDP-2 drillhole is under review and the prime candidate is essentially the same as the 1st priority site suggested for the Reykjanes field in 2003. More recent drillhole data and new MT surveys have amplified the justification for selecting that site. Deep drilling to 4–5 km depth is an important part of the HS Orka exploration strategy for enhanced power production, either by direct use of high energy steam, or by attempting to enhance the field performance by re-injecting geothermal fluid deep into very hot rocks. Pending on several decisions and development in Iceland, outside the control of the IDDP energy consortium, the IDDP-2 well might possibly be drilled to 4–5 km depth as early as 2014.

The introduction of low-temperature fluid into boreholes drilled in ice sheets helps to remove drilling cuttings and to prevent borehole closure through visco-plastic deformation. Only special fluids, or mixtures of fluids, can satisfy the very strict criteria for deep drilling in cold ice. The effects of drilling fluid on the natural environment are analyzed from the following points of view: (1) occupational safety and health; (2) ozone depletion and global warming; (3) chemical pollution; and (4) biological pollution. Traditional low-temperature drilling fluids (kerosene-based fluids with density additives, ethanol and n-butyl acetate) cannot be qualified as intelligent choices from the safety, environmental and technological standpoints. This paper introduces a new type of low-temperature drilling fluid composed of synthetic ESTISOLTM esters, which are non-hazardous substances. ESTISOLTM 140 mixtures with ESTISOLTM 165 or ESTISOLTM F2887 have an acceptable density and viscosity at low temperature. To avoid the potential for biological contamination of the subglacial environment, the borehole drilling fluid should be treated carefully on the surface.

Drum-shaped stone tongue that there are 3 ~ 5 m thick wedge silt on the bottom formed in the junction of silt and the stone embankment by reclamation silt with mountain stone during the course of backfill. In the paper, on the basis of drills, superficia drilling holes, deep drilling holes and vibrating stop plank model, boundary stone embankment shape and soft soil layer depth were obtained, cross section of stone embankment and stone embankment boundary were revealed during the course of artificial fill, study the stone tongue shape, soft soil around stone tongue, silt characters on stone tongue bottom and reinforcement treatments were studied to obtain treatment method which can satisfy the engineering requirement and can save the engineering cost and provide mature construction technology and method for the similar subgrade treatment of sea reclamation engineering.

Continuous development of science and technology, the human ability to conquer nature and continuously improve, but also rapid growth in social demands, significantly reduced the amount of available resources. Earth-shallow layer drying up of resources of our human life, forcing people to the underground exploration of the deeper substance to meet human needs. This requires adaptation of deep drilling tool for drilling needs good equipment, deep-hole wireline coring drilling equipment in adapting to constantly update and be perfect with this demand.

Because the hard strata and big angle of bedding, deep wells in Daqing Xujiaweizi area well deviate easily. Low efficiency and long drilling cycle are big problems of drilling engineering since small bit weight is used to avoid well deviation. To improve efficiency, Smooth drill collars with high bit weight WOB technology is used in the deep wells in Daqing Xujiaweizi area. Facts prove that penetration rate can be increased more than 20% , bit life can be extended more than 30% and well deviation can be corrected in Daqing Xujiaweizi deep drilling. This paper through analyzes the mechanism of smooth drill collars BHA ,then build kinematic model and dynamic mode,so bit side force's Solution formula is worked out,Get the principles and applicability of smooth drill collars with high bit weight WOB technology.

Rotary drilling rigs, general construction equipment, are widely used for deep drilling of ground for the foundations of public works. A new 250kN.m-type rotary drilling rig, most widely used in this field, is under development, and this study focuses on the operational safety of the mast subassembly on the basis of structure analysis of the mast subassembly using a finite element method with ANSYS. When using a drilling rig, an electric rotary drive supplies power for drilling. Here, the elevation of the rotary drive along the mast needs to be changed according to the geological construction environment. Through the analysis, the allowable torques at various elevations of the rotary drive are evaluated, also the safety of the drilling tool called the kelly bar subassembly is examined. Finally, the suitability of the mast subassembly design is examined from the analysis results.

Deep geothermal exploration in the UK in the 1980s resulted in only one operative borehole (in Southampton). In 2004, a 995 m deep borehole was drilled into the Weardale granite in County Durham. This project differed markedly from the earlier ‘hot dry rock’ investigations in the granites of Cornwall, in that it deliberately targeted possible high natural permeability derived from large fault zones. The new approach met with success, discovering what is believed to be the highest natural permeability ever found in granite anywhere in the world. Drilling of a second borehole at Eastgate in 2010 confirmed that high permeability is preferentially associated with major west–east geological faults. Further deep drilling is now targeting similar faults cutting nearby sedimentary sequences. Meanwhile, renewed interest is being shown in Cornish prospects, as well as in previously unexplored resources in Scotland and Northern Ireland. There is also significant interest in the possible geothermal exploitation of hot brines, which are co-produced with hydrocarbons in existing oilfields. Technological advances in directional drilling, reservoir stimulation and power generation using binary-cycle turbine plants are finally making deep geothermal energy a realistic target for full-scale development in the UK.

Over the past years, deep drilling technology developed quickly. New technologies better quality of drilling work and accelerated the drilling process. At present, 20-25% are new techniques while 75-80% drilling methods used worldwide are traditional. Slovakia is quite at the rear of this tendency: our utilization ration shows 95-98% traditional drilling methods, in comparison to only 2-5% new ones. Advancement of new deep well boring technologies causes the evolution of new types of drilling sets for deep drilling (depending on applied techniques). Techniques used have a mechanical and physical impact for drilling of rock. Several tests and analyses of disintegration and drilling methods were performed over the last years. The article focuses on a description of the working principle and utilization possibilities.

This paper presents a new approach to developing the torque model in deep hole drilling, both for conventional and ultrasonic assisted drilling processes. The model was proposed as a sum of three components: the cutting, the chip evacuation and the stick-slip torques. Parameters of the new model were carried out by applying the regression analysis technique, with the correlation values higher than 0.999. The data were collected from 36 experimental dry drilling tests, both in conventional and ultrasonic assisted cutting conditions, with the depth-to-diameter of the drilled holes of 7.5. The major advantage of the new model compared to previous models is that the new model of chip-evacuation torque has only one coefficient, thus making it easier to evaluate and compare different deep-drilling processes. The effectiveness of ultrasonic assistance in deep hole drilling was also highlighted using the proposed model. The new model is promising to predict critical depth and torque in deep hole drilling.

This paper presents an experimental study of the positive effects of vibration-assisted deep drilling of aluminum alloy Al-6061. The four most important evaluation criteria in drilling&mdash, machinability, workpiece temperature, torque, and material removal rate&mdash, were chosen to be investigated. Holes with a depth-to-diameter ratio of 13 were drilled by high speed steel (HSS) twist drill bits of 3 mm diameter, using both methods of conventional drilling (CD) and ultrasonic-assisted drilling (UAD). Three levels of axial force of 6 kgf, 9 kgf, and 12 kgf were kept constant for each pair of comparison experiments. It was found that workpiece temperature and torque not only changed from one drill to the other, but were also dependent on the hole depth being drilled. Comparisons were made in-pair between CD and UAD under the same axial force and at the same order of hole numbers. The result shows that the material removal rate with UAD was up to 3.5 times higher than that with CD and the average workpiece temperature and torque in UAD were reduced by 3.5 and 6 times, respectively. Moreover, tool life in UAD was observed to increase from 2.5 to 5 times, in terms of number of holes drilled, compared to that in CD.

The Swedish Deep Drilling Program (SDDP) has been initiated to study fundamental problems of the dynamic Earth system, its natural history and evolution. Many key scientific questions can be addressed through in situ investigations only, requiring deep continental drilling. Some are unique to Scandinavia, most are of international interest and significance. At present, five core projects (Fig. 1) with international teams are integrating scientific problems with societal and industrial applications. If SDDP succeeds to attract the funding required, Sweden will have a number of world-class boreholes at key locations by 2020.

This paper highlights the development of micro long flat drills with nominal diameter and flute length of 20 μm and 200 μm, respectively, by precision grinding. Furthermore, it also covers the evaluation of the developed micro long flat drill in micro deep drilling. Micro long flat drills were made of ultra-fine grained cemented carbide containing WC particles with an average particle diameter of 90 nm. First, the study focused on establishing the optimal web thickness of micro long flat drill showing the best performance in micro deep drilling. In drilling experiment, observation was conducted with the aim of finding the best conditions and method of micro deep drilling into both duralumin and stainless steel workpieces. This observation included the applications of ultrasonic vibration (USV) and step feeding method. The study proved that there was an optimum web thickness resulting in the best drilling performance. Furthermore, the application of USV during drilling could lead to a longer tool life significantly. However, there was no improvement of drilling performance in drilling with step feeding.

The Huangtuliang gold deposit is characterized by its wide and large ore belt, stable extension and closely spaced orebodies. Unfortunately, no orebody was found by deep drilling. As a result, ore prospecting in this region was once put into dilemma. Detailed analysis of ore-forming and ore-controlling structures in the mining district by the authors has revealed that the ore-forming and ore-controlling structure in this mining district is a steeply dipping (85°−110°/∠70°–85° N-NNE), spade-shaped ductile shear zone, and the ore-controlling structures are a series of nearly erected second-ordered faults which are developed in the upper part of the ductile shear zone, intersecting with the ductile shear zone. Deep cutting of the ductile shear zone made it possible the ascending of ore fluids from the mantle plume at depth and these ore fluids would migrate upwards along the ductile shear zone under certain temperature and pressure conditions. Along their ascending path, the ore fluids would extract ore-forming elements from the country rocks and the extracted ore-forming elements would be deposited as ores in the hanging-wall second-ordered faults. The reason why no orebody was found in early prospecting at depth is that northward-dipping drilling in the southern part of the shear zone extended so deeply as to be beneath the shear zone. Only shallow-level orebodies could be found by southward-dipping drilling practice in the northern part of the shear zone. The location where deep-seated orebodies occurred shifted northwards and the orebodies occurred at greater depth. Therefore, it is natural that no orebody could be found when drill core passed through the shear zone. After the ore-forming and ore-controlling structures were well understood, the focus of ore prospecting was placed on the deep-level, northward-penetrating veins. In this way a number of new blind orebodies of great thickness have been found. On the basis of research development in the mining district, a prospecting plan has been made for ore prospecting in the periphery of eastern mining district. Prospecting practice has shown that there occur generally continuous engineering orebodies at large intervals. So, the Huangtuliang gold deposit has turned at one stroke from a medium sized to a large-sized, even a super-large gold deposit between prospecting lines 30–98.

Deep hole machining accuracy plays a crucial role in product’s quality. The results of an investigation into the machining accuracy of deep drilling holes which highlights problems of bore diameter enlargement magnitude assessment are presented in this paper. Through the study of BTA deep drilling tool properties and mechanism, as well as the formation rule of deep hole surface, clarified the burnishing mechanism of guide pad in deep hole drilling, and obtained the directly relationship between surface formation rule and the guide pad. After drilling experimentrevealed the effect of guide pad on bore diameter enlargement magnitude.

Gundrill boring operations are sometimes used to obtain holes with high surface quality and accuracy requirements, impossible to fulfill using core drilling techniques. This article presents a feasibility study concerning the use of vibration drilling technique for gundrill boring operations, in order to ease the chip extraction by periodical breaking. Mathematical models defining a methodology used in order to compute and/or choose system parameters are presented. Rubbing effect is discussed and its influence is proved to be much smaller than for core drilling. Experimental results presented validated mathematical models and give hopes for a possible industrialisation.

Early development of marine electromagnetic methods, dating back about 80 years, was driven largely by defense/military applications, and use for these purposes continues to this day. Deepwater, frequency-domain, electric dipole-dipole, controlled-source electromagnetic (CSEM) methods arose from academic studies of the oceanic lithosphere in the 1980s, and although the hydrocarbon exploration industry was aware of this work, the shallow-water environments being explored at that time were not ideally suited for its use. Low oil prices and increasingly successful results from 3D seismic methods further discouraged investment in costly alternative geophysical data streams. These circumstances changed in the late 1990s, when both Statoil and ExxonMobil began modeling studies and fieldtrials of CSEM surveying in deep water (around [Formula: see text] or deeper), specifically for characterizing the resistivity of previously identified drilling targets. Trials offshore Angola in 2000–2002 by both these companies showed that CSEM data can successfully be used to evaluate reservoir resistivity for targets as deep as several thousand meters. Both companies leveraged instrumentation and expertise from the academic community to make swift progress. The resulting rapid growth in the use of marine EM methods for exploration has created a demand for trained personnel that is difficult to meet; nevertheless, at this time, CSEM data represent a commercial commodity within the exploration business, and acquisition services are offered by three companies. The ability to determine the resistivity of deep drilling targets from the seafloor may well make marine CSEM the most important geophysical technique to emerge since 3D reflection seismology.

Deep drilling into the ice sheet at Vostok station, Antarctica, was started by specialists of the Leningrad Mining Institute (since 1991, St Petersburg State Mining Institute) in 1970. Five deep holes were cored: hole No. 1 to 952 m; hole No. 2 to 450.4 m; hole No. 3G (3G-1, 3G-2) to 2201.7 m; hole No. 4G (4G-1, 4G-2) to 2546.4 m; and hole No. 5G (5G-1) to 3650.2 m depth. Drilling of hole 5G-1 is not yet complete. The deep drilling at Vostok station has had successes and problems. All the deep holes at Vostok have undergone at least one offset drilling operation because of problems with lost drills. These deviations were made successfully using a thermal drilling technique. Several drilling records have been achieved at Vostok station. The deepest dry hole, No. 1 (952 m), was made during Soviet Antarctic Expedition (SAE) 17 in 1972. The deepest fluid-filled hole, No. 5G-1, made by a thermal drill (TBZS-132), reached 2755 m during SAE 38 in 1993. The deepest fluid-filled hole in ice, No. 5G-1, was drilled with a KEMS-132 electromechanical drill and was stopped above Vostok Subglacial Lake at 3650.2 m depth during Russian Antarctic Expedition (RAE) 51 in 2006.

Finding a new safe and ecologically friendly borehole fluid is one of the most pressing problems for forthcoming ice-drilling projects. Not all recent borehole fluids qualify as intelligent choices from safety, environmental and other technological standpoints. We propose the use of silicone oils as the borehole fluid. The most suitable type of silicone oils for deep ice drilling are low-molecular (or volatile) dimethyl siloxane oils (DSOs). Low-molecular DSOs are clear, water-white, tasteless, odorless, neutral liquids. They are hydrophobic and inert substances that are stable to water, air, oxygen, metals, wood, paper, plastics, etc. Of the DSOs, class 2 grades of KF96-1.5cs and KF96-2.0cs most fully fit our criteria for choice as borehole fluids. The final conclusion as to the suitability of DSOs for ice deep drilling will be made after the experiments in a test borehole.