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Often there is no well drilling without problems. The solution lies in managing and evaluating these problems and developing strategies to manage and scale them. Non-productive time (NPT) is one of the main causes of delayed drilling operations. Many events or possibilities can lead to a halt in drilling operations or a marginal decrease in the advancement of drilling, this is called (NPT). Reducing NPT has an important impact on the total expenditure, time and cost are considered one of the most important success factors in the oil industry. In other words, steps must be taken to investigate and eliminate loss of time, that is, unproductive time in the drilling rig in order to save time and cost and reduce wasted time. The data of six oil wells were approved for the purpose of the study, where it was noted that there are many factors affecting the NPT, which differ from one well to another. Its impact was limited to drilling rig, mud pump and equipment failure. There is also a difference between the planned program and what is actually happening on the ground, due to several reasons, including human errors during the implementation of the drilling program and others due to technical errors, Misuse of equipment, in addition to human errors related to the failure to implement the drilling program. [ABSTRACT FROM AUTHOR]

Fouling and mud-pumping problems in ballasted track significantly degrade serviceability and jeopardize train operational safety. The phenomenological approaches for post hoc forensic investigation and remedies of mud pumps have relatively been well studied, but there still lacks studies on inherent mechanisms and ex ante approaches for early-age detection of mud pumps. This paper was aimed to exploring the feasibility of using particle acceleration responses to diagnose and identify early-age mud-pumping risks in real-world field applications. The innovative wireless sensors with 3D-printed shells resembling real shape of ballast particles were instrumented in the problematic railway section to monitor ballast particle movement prior to, during, and after maintenance operations, respectively. The real-time particle-scale acceleration data of ballast bed under both degraded and maintenance-restored clean conditions were recorded. The time histories, power spectra, and marginal spectra of 3D acceleration were comparatively analyzed. The results showed the 3D acceleration of ballast particles underneath rail-supporting tie plates displayed relatively clear periodicity of about 0.8 s with adjacent bogies regarded as a loading unit. The tamping operation was effective for compacting ballast bed laterally and improving the lateral interlocking of ballast particles, whereas the stabilizing operation was effective mainly in the lateral direction and for ballast particles underneath the sleepers. The mud pumps caused intensive particle-scale acceleration, and ballast particles underneath the sleepers were affected more severely than those in between adjacent sleepers. The ballast particles directly underneath tie plates exhibit dramatic acceleration variations due to maintenance operations as compared to those in other positions studied; hence, it seems promising to use particle-scale acceleration underneath tie plates as readily-implementable indicators for smart in-service track health monitoring. [ABSTRACT FROM AUTHOR]

Fouling and mud-pumping problems in ballasted track significantly degrade serviceability and jeopardize train operational safety. The phenomenological approaches for post hoc forensic investigation and remedies of mud pumps have relatively been well studied, but there still lacks studies on inherent mechanisms and ex ante approaches for early-age detection of mud pumps. This paper was aimed to exploring the feasibility of using particle acceleration responses to diagnose and identify early-age mud-pumping risks in real-world field applications. The innovative wireless sensors with 3D-printed shells resembling real shape of ballast particles were instrumented in the problematic railway section to monitor ballast particle movement prior to, during, and after maintenance operations, respectively. The real-time particle-scale acceleration data of ballast bed under both degraded and maintenance-restored clean conditions were recorded. The time histories, power spectra, and marginal spectra of 3D acceleration were comparatively analyzed. The results showed the 3D acceleration of ballast particles underneath rail-supporting tie plates displayed relatively clear periodicity of about 0.8 s with adjacent bogies regarded as a loading unit. The tamping operation was effective for compacting ballast bed laterally and improving the lateral interlocking of ballast particles, whereas the stabilizing operation was effective mainly in the lateral direction and for ballast particles underneath the sleepers. The mud pumps caused intensive particle-scale acceleration, and ballast particles underneath the sleepers were affected more severely than those in between adjacent sleepers. The ballast particles directly underneath tie plates exhibit dramatic acceleration variations due to maintenance operations as compared to those in other positions studied; hence, it seems promising to use particle-scale acceleration underneath tie plates as readily-implementable indicators for smart in-service track health monitoring.

Water-filled boreholes in cold ice refreeze in hours to days, and prior attempts to keep them open with antifreeze resulted in a plug of slush effectively freezing the hole even faster. Thus, antifreeze as a method to stabilize hot-water boreholes has largely been abandoned. In the hot-point drilling case, no external water is added to the hole during drilling, so earlier antifreeze injection is possible while the drill continues melting downward. Here, we use a cylindrical Stefan model to explore slush formation within the parameter space representative of hot-point drilling. We find that earlier injection timing creates an opportunity to avoid slush entirely by injecting sufficient antifreeze to dissolve the hole past the drilled radius. As in the case of hot-water drilling, the alternative is to force mixing in the hole after antifreeze injection to ensure that ice refreezes onto the borehole wall instead of within the solution as slush. [ABSTRACT FROM AUTHOR]

Underground directional drilling is an important technique to prevent and control water disasters in coalmines. However, the drilling efficiency is generally low in hard rocks, and the conventional hydraulic impactor is not applicable to underground directional drilling. To solve these problems, this paper designs a flexible impact positive displacement motor (PDM) control system, and specified the calculation methods for the relevant hydraulic parameters. Specifically, the hydraulic oscillator and conventional PDM were combined into a PDM with axial impact function. Then, the rolling-in method was introduced to determine the motion law of the disc valve, and compute the time variation of the flow area. The calculation methods were developed for the hydraulic parameters of flexible impact PDM, and adopted to compute the hydraulic parameters of Ф95mm PDM. During the calculation of the axial impact force, the fluctuating pressure difference was preset as per the pump capacity, and the multi-stage piston design was employed to produce a high axial impact force under a small pressure difference; the orifice parameters were calculated based on the fluctuating pressure difference; the impact frequency was derived from mud pump displacement, and the rotation speed and revolution-rotation speed ratio of the rotor. The results show that, when the displacement is 6.5L/s (the normal displacement underground the coalmines), the impact frequency is 12.5Hz, the fluctuating pressure difference is 1.54MPa, the impact force is 15.54kN, the inner diameter of the piston is 35mm, the outer diameter of the piston is 75mm, the offset distance of the disc valve is 4.5mm, and the orifice radius is 9.2m. The calculated results deviated from the prediction of backpropagation neural network (BPNN) by less than 5%, indicating that the structure of the proposed flexible impact PDM is feasible, and that the hydraulic parameters are calculated simply and accurately. To sum up, this research designs a PDM that can theoretically improve the rock-breaking efficiency in hard stratum, providing an important reference for similar research. [ABSTRACT FROM AUTHOR]

This paper investigates behavior and control of the ballastless track-subgrade vibration induced by high-speed trains under mud pumping occurring in the subgrade bed. The characteristics of mud pumping occurring in the subgrade bed under the ballastless track structure are analyzed by visual observation and nondestructive testing. Then, based on the injection of the low-viscosity epoxy resin (LVER), the repair procedures for the mud pumping are proposed. A variety of on-site tests are performed on the ballastless track-subgrade with and without mud pumping and also after mud pumping reinforcement to analyze the vibration of the ballastless track-subgrade under the high-speed trains. The test results show that mud pumping can significantly increase the vertical vibration acceleration and displacement of the ballastless track structure and slightly decrease the vibration of subgrade surface. After mud pumping reinforcement, the abnormal vibration of the ballastless track-subgrade can be effectively controlled to make the vibration close to normal. In addition, the vibration ratio of the subgrade surface to the concrete base is proposed as a way to evaluate the effectiveness of the reinforcement of the mud pumping using the LVER, based on the vibration attenuation feature of the ballastless track-subgrade. [ABSTRACT FROM AUTHOR]

Although mud pumps are vital components of a drilling rig, their failures are frequent. The identification of technical condition of these high-pressure piston pumps is difficult. There are no reliable criteria for the assessment of mud pump condition. In this paper, faults of the pump valve module are identified by means of acoustic emission (AE) signals. The characteristics of these signals are extracted by wavelet packet signal processing. This method has been verified by experiments conducted on a NOV (National Oilwell Varco) -made triplex 14-P-220 mud pump (mounted in the drillship). The results show that the wavelet packet signal processing method can effectively extract the frequency band energy eigenvalues of the signals. Besides, some operational problems associated with high pressure piston mud pumps are presented. A non-invasive method for diagnosing the technical condition of such pumps is being developed at the Maritime University of Szczecin.

The use of the finite element method for analyzing fluid flow models has become a common method of analysis, by developing of the advanced programs: Ansys, Caeplex, Comsol Multiphysics, Conself, Nastran, NX 8 CAE, Solidworks Flow Simulation. The use of these programs allows the real system modeling to capture the asymmetries of the construction and introduces a velocities distribution in agreement with them. Based on the materials defined for the elements used in the modeling and the calculation relationships entered into the program, the erosion value can be estimated over a certain time interval. It is also possible to study the flow of fluids in which abrasive particles (detritus in the case of mud pumps) of certain sizes or mixtures of particles of different sizes are introduced. The article presents the use of these possibilities in the design of the mud pump valve. [ABSTRACT FROM AUTHOR]

The possibility of extending the service life of the cylindrical liners of U8-6MA mud pumps is considered. It is suggested that cylindrical liners that have, to some extent, become worn out should be bored out and twin liners fabricated. The diametrical dimensions of the twin liners are given and the resulting forces that arise in the course of the shaft's travel are calculated. Alternative rebore options under which the condition T < P holds are given. [ABSTRACT FROM AUTHOR]

A mud pump is one of the three key components of a drilling site and its lifetime and reliability are related to safety and cost. The fluid end, which mainly comprises the pump valve and piston, is the most easily damaged part of the mud pump. To ensure normal operation, the fault modes of the fluid end need to be effectively identified. In this paper, the fault mode is identified using multi-sensor information fusion, which fuses the acoustic emission (AE) signal and the vibration acceleration signal. The features of these signals are extracted using wavelet packet signal processing; then, the faults are diagnosed using neural network algorithms. This method is verified by conducting experiments on a BW-250 triplex mud pump and the results show that the wavelet packet signal processing method can effectively extract the frequency band energy eigenvalues of the signals and that the fault diagnosis accuracy is improved by using multi-sensor information fusion. This research presents a practical diagnosis method that can effectively improve the fault diagnosis level for the fluid end of high-pressure reciprocating mud pumps. [ABSTRACT FROM AUTHOR]

The drilling process requires the transportation of the drilling fluid (mud) loaded with high abrasive materials like sand and rock cuttings. The drilling mud is transported through the close running clearance of the valve opening at high flow velocities, producing high abrasive wear within a short period of time. As the drilling process makes it impossible to operate the pump at lower speed in order to reduce the flow velocity through the valves, the valve protection against abrasive wear can be realized by the following actions: – designing the valve to control the flow stream, avoiding abrupt changes in flow direction, close clearances and turbulent flow; – using abrasive wear resisting materials by applying hardfacing technologies, such as case hardening, cladding by weld overlays and coating by thermal spray techniques. This article is based on a comparative investigation of these methods for protection of the valve seat's working surface, operating under abrasive wear conditions. The comparison is based on the analysis of microstructure and hardness obtained by applying different hardfacing technologies. [ABSTRACT FROM AUTHOR]

The railroad track is one of the few geosynthetic applications in which a geosynthetic is used for multiple functions, namely, reinforcement, separation, filtration and drainage. In the present study, static and cyclic tests were performed on full-panel railway track models laid on compacted soil subgrades. Tests were performed on model tracks with two different thicknesses of subballast layers and laid on two different subgrade soils, namely, Dhanaury clay and Delhi silt. Model tracks were adequately instrumented to record induced stresses and displacements in the track. Model tracks were reinforced with a geogrid or a geotextile or both at suitable interfaces. Track conditions after heavy rainfall were simulated. The model tracks reinforced with a geogrid at the ballast–subballast interface were more effective in reducing the tie displacements, ballast and subballast strains and subgrade displacements compared to the model tracks reinforced with a geotextile at the subballast–subgrade interface when Dhanaury clay was used as the subgrade soil. Conversely, the model tracks reinforced with a geotextile performed better with respect to reduced tie displacement, subgrade displacement and subballast strain compared to the model tracks reinforced with a geogrid when Delhi silt was used as the subgrade soil. [ABSTRACT FROM AUTHOR]

Laboratory tests were conducted on track materials to evaluate constitutive parameters for three different sets of constitutive relationships, namely, non-linear analysis, straight analysis and coupled analysis. The model test results of finite element analyses using various constitutive relationships are compared. The coupled analysis provided a better prediction of the measured results compared to the non-linear and straight analyses. A detailed parametric study of a prototype track was then performed using the coupled analysis to evaluate the effects of geosynthetics on track reinforcement and mud-pumping reduction. Geogrid reinforcement was found to significantly reduce tie displacement only at low subgrade modulus values and effective subgrade shear strength parameters. Geogrid reinforcement was equally effective at reducing tie displacement within the subballast thickness range of 450–1000 mm. High excess pore water pressure coupled with low effective cohesion gives rise to mud-pumping problems in silty soil subgrades. The provision of geotextiles at the subgrade surface facilitates quick in-plane drainage and dissipation of pore water pressure. Thus, excess pore water pressure was observed to be lower in a geotextile-stabilized track compared to that in an unreinforced track, indicating reduction in mud-pumping potential in the former. [ABSTRACT FROM AUTHOR]

This article examines the differences in the lifetime of mud pumps, which are part of the equipment on (ultra) deep-water drillships, depending on the strategy of maintenance. The authors conducted research on mud pumps to create an efficient diagnostic tool to help pumps operators on daily maintenance routines. We have created drilling process diagrams, one pertaining to the operation of mud pumps for which maintenance is carried out without technical supervision, the other including diagnostic maintenance. The diagrams show differences pump failure frequency. [ABSTRACT FROM AUTHOR]

Controlled mud-cap (CMD) drilling is an advanced deepwater drilling technology. When the surface pump is shut down, the CMD system causes unsteady flow that may create control problems. A new mathematical model has been developed to simulate unsteady flow in CMD systems. The model predicts the transient flow, the equilibrium time, and the change in bottomhole pressure during the unsteady flow. The simulation results show that the flow parameters change rapidly during the first 10 min and that unsteady flow leads to fluctuations in bottomhole pressure. In combination with measured data, the transient flow behavior computed by the model can be used for early detection of well kick after shutdown of the mud pump. [ABSTRACT FROM AUTHOR]

A procedure for calculating the pressure and power of a mud pump used in drilling an extendedreach well is described. A method is proposed for determining the hydraulic extension limit length in the drilling process depending on the rated pressure and power of the pump. An example is given of maximum well depth calculation with allowance for the limitations of a specific pump having fixed characteristics. [ABSTRACT FROM AUTHOR]

This paper presents the methodology used to evaluate the materials resistance to erosive wear, from the needed equipment to the steps to be followed during experiments. In order to choose the correct method for wear testing and to design the needed equipment, it is necessary to study the wear tests available on the market. The equipment and the methodology for erosive wear assessment, presented in the paper, have been designed and completed for mud pumps components and, after preliminary tests regarding the efficiency of the method, it can be applied for various hardened materials subjected to intense wear in operation. [ABSTRACT FROM AUTHOR]

Cylinder sleeves, a key component of drilling mud pump, often wear because of hydraulic friction, although they are made of SiAlON materials. In this paper, a cylinder sleeve of the drilling mud pump was developed under the high-temperature condition using SiAlON ceramic, which is made of Si, Al and SiC. The results show that the density of SiAlON ceramic decreases with an increasing content of SiC, while the porosity does not. Toughness of the SiAlON ceramic samples are ranged between 25 and 55 MPa. The minimum compressive strength is 266 MPa. The addition of SiC can increase the anti-erosive wear of the SiAlON. In terms of physical and mechanical properties, the SiC with z = 2.5 and 10% was finally optimized. [ABSTRACT FROM AUTHOR]

The results of study of the occurrence of the phenomenon of narrowing of holes in cylindrical bushings of U8-6MA2 mud pump after high-frequency induction hardening are cited. The study of the occurrence of narrowing of holes helps predict the magnitude of allowance for final grinding operation. The physical aspect of this phenomenon is explained. The obtained results are recommended for use while fabricating bushing type of parts. [ABSTRACT FROM AUTHOR]

Results are presented for metallographic and x-ray structural analyses of wear and damage features of a geological exploration pump type Gr16/40 valve pair, plate, and seat. [ABSTRACT FROM AUTHOR]

The article presents selected technical issues relating to drilling performed by a drillship, one type of drilling rigs. Basic problems encountered in the main function of such rigs - drilling a well - are failures of mud pumps. The authors investigate these pumps in operational conditions, aiming at development of a system for monitoring the technical condition of these pumps. Work on a diagnostic system is in progress that will permit to predict the condition of mud pump valves well in advance. [ABSTRACT FROM AUTHOR]

Computation model of crankshaft was built and the dynamic characteristics of crankshaft were studied. FEM was performed to obtain the maximum main stress, the minimum main stress and the Mises stress at three kinds of critical working conditions of crankshaft. Through movement analysis and computation for various components of reciprocating mud pump (RMP), the loads of crankshaft were obtained. The maximum stress of crankshaft at the three kinds of dangerous operating modes was obtained from the FEM stress analysis. It is located in the critical region and the location belongs to the dangerous position in most of the fracture crankshafts. The FEM stress analysis results are very valuable in guiding actual application development for intelligence optimization design of RMP. [ABSTRACT FROM AUTHOR]

This study presents a mud pumping equipment that can be attached to the excavator arm. This equipment can solve ecological issues in narrow spaces, in areas where access is limited as well as during floods. The technological constructive designing for this type of equipment may be considered by extension as diversity of equipments that can be attached to the excavator arm. [ABSTRACT FROM AUTHOR]

The promising methods of hardening rapidly wearing friction pairs of mud pumps are analysed, and the efficiency of using plasma powder surfacing for increasing the service life of sleeves of cylindrical and valve sections is indicated. The results of laboratory and industrial tests carried out to determine the possibility of application of plasma wear-resisting coatings for the rods of NB32-125 pumps are presented. [ABSTRACT FROM PUBLISHER]

Accurate estimation of the frictional pressure losses for non-Newtonian drilling fluids inside annulus is quite important to determine pump rates and select mud pump systems during drilling operations. The purpose of this study is to estimate frictional pressure loss and velocity profile of non-Newtonian drilling fluids in both concentric and eccentric annuli using an Eulerian-Eulerian computational fluid dynamics (CFD) model. An extensive experimental program was performed in METU-PETE Flow Loop using two non-Newtonian drilling fluids including different concentrations of xanthan biopolimer, starch, KCl and soda ash, weighted with barite for different flow rates and frictional pressure losses were recorded during each test. This study aims to simulate non-Newtonian fluids flow through both horizontal concentric and eccentric annulus and to predict frictional pressure losses using an Eulerian-Eulerian computational fluid dynamics (CFD) model. Computational fluid dynamic simulations were performed to compare with experimental data gathered at the METU-PETE flow loop and previous studies as well as slot flow approximation for the annulus. Results show that the computational fluid dynamic model simulations are capable of estimating frictional pressure drop with an error of less than 10% in most cases, more accurately than the slot equation. [ABSTRACT FROM AUTHOR]

The article mentions about the automation of mud-pump management system for drilling operations in North Sea. Automation of mud-pump management system was required because drilling in North Sea is very challenging, due to narrow geopressure windows in depleted reservoirs and occurrence of packoffs, thus leading to the formation of nonproductive time. Automatic control also helps in updating mud pumps under continuous changing conditions including depth, temperature and flow-rate.

This paper presents results of field studies on unpaved low volume roads constructed over weak subgrade using geosynthetic reinforcement. The relative advantages of placing different reinforcing materials like geotextile, biaxial or uniaxial geogrid, geocell layer and tire shreds at the interface of subgrade and base course are studied in terms of increase in load carrying capacity and reduction in rut depth. The rut depths measured in three different test sections when subjected to moving vehicle load simulated by the passage of a scooter on the road at uniform speed for a maximum of 250 passes are compared to understand the relative efficiency of each of these reinforcing materials in reducing the rut formation in unpaved roads. Traffic benefit ratios were also compared for different reinforced test sections. [ABSTRACT FROM AUTHOR]

Micro pumps are essential components of micro devices such as drug delivery systems. Large numbers of pumps have been proposed based on different actuating principles. Piezoelectric actuation offers advantages such as reliability and energy efficiency. Lead zirconate titanate (PZT) based piezoelectric actuation for micro pumps is predominantly explored despite its disadvantages such as brittle nature, low straining and difficulties in processing. Polymer piezoelectric materials like polyvinylidene fluoride (PVDF) could be promising replacements for PZT owing to their availability in form of films and good strain coefficients. Very limited literature on micro pump with PVDF as an actuator is available. In this paper, finite element analysis (FEA) model of a micro pump actuator using single and multilayer PVDF for actuation is developed in ANSYS . The model takes into account the influence of driving voltage and actuator geometry. The central deflection of the pump diaphragm which is instrumental in defining the pump performance is studied for driving voltages of 100-200 V. The deflection of the pump diaphragm for single layer and multilayer actuation are determined from the model. It could be inferred from the initial part of the study that pump performance depends on driving voltage and actuator film thickness. In order to reduce driving voltage requirement multilayer stacked actuator is tried with four different configurations of the layers. It is concluded that stacking configuration of parallel energized straight polarity PVDF layers yielded best central deflection. An attempt is made to compare the performance of multilayer actuator with an equivalent single thick layer actuator. It is noticed that the multilayer actuator performance was better by about 101% when number of layers is doubled. [ABSTRACT FROM AUTHOR]

The article presents a study on drilling fluids' pressure/volume/temperature (PVT) behavior. Emulsions and methane mixtures were analyzed to understand their PVT behavior and the results were compared with certain data. The study found that as the temperature increased, the mixture density decreased and formation volume factor increased. It concludes that mixture composition, temperature, and pressure affect gas/SBM interaction.

The objective of this study was to identify the descriptive tests for drilling stable holes through the problems of the selected formations. This study was performed on the shale samples taken from 10 wells in which hole instability was encountered to various extents during drilling the Germav formation. A total of 13 formation samples, characterizing the problematic intervals of the 10 wells under consideration, were evaluated. Descriptive tests were used to compare the samples and to determine the samples that should be used for drilling fluid selection tests. Based on the results of these tests it is possible to select the best drilling fluid for the formations studied. Descriptive tests include x-ray analysis, capillary suction time, hot rolling test, linear swelling test and cation exchange capacity test. [ABSTRACT FROM AUTHOR]

Technical data are presented for the following pumps: two-piston (double-acting), three-piston (single- and double-acting), and universal slush. New designs of the pumps are described. [ABSTRACT FROM AUTHOR]

Although mud pumps are vital components of a drilling rig, their failures are frequent. The identification of technical condition of these high-pressure piston pumps is difficult. There are no reliable criteria for the assessment of mud pump condition. In this paper, faults of the pump valve module are identified by means of acoustic emission (AE) signals. The characteristics of these signals are extracted by wavelet packet signal processing. This method has been verified by experiments conducted on a NOV (National Oilwell Varco) -made triplex 14-P-220 mud pump (mounted in the drillship). The results show that the wavelet packet signal processing method can effectively extract the frequency band energy eigenvalues of the signals. Besides, some operational problems associated with high pressure piston mud pumps are presented. A non-invasive method for diagnosing the technical condition of such pumps is being developed at the Maritime University of Szczecin. [ABSTRACT FROM AUTHOR]