Drilling Conditions Research Articles

Investigating the efficacy of novel organoclay as a rheological additive for enhancing the performance of oil-based drilling fluids

Oil-based drilling fluids (OBDFs) are extensively used in the drilling industry due to their superior performance in challenging drilling conditions. These fluids control wellbore stability, lubricate the drill bit, and transport drill cuttings to the surface. One important component of oil-based drilling fluids is the viscosifier, which provides rheological properties to enhance drilling operations. This study evaluates the effectiveness of Claytone-IMG 400, a novel rheological agent, in enhancing the performance of OBDFs under high-pressure and high-temperature (HPHT) conditions. A comparative analysis was conducted with a pre-existing organoclay (OC) to assess the improvements achieved by Claytone-IMG 400. The OCs were analyzed using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and particle size distribution (PSD) to identify their mineral and chemical compositions, morphologies, and particle sizes. The drilling fluid density, electrical stability, sagging tendency, rheological properties, viscoelastic properties, and filtration properties were studied to formulate a stable and high-performance drilling fluid. The results confirmed that the novel OC does not affect the drilling fluid density but enhances the emulsion stability with a 9% increment compared with the drilling fluid formulated with MC-TONE. The sagging experiments showed that Claytone-IMG 400 prevented the sagging issues in both static and dynamic conditions. Also, Claytone-IMG 400 improved the plastic viscosity (PV), yield point (YP), and apparent viscosity (AV). The PV, YP, and AV were improved by 30%, 38%, and 33% increments respectively compared with the drilling fluid formulated with MC-TONE. The YP/PV ratio increased with a 6% increment from 1.12 to 1.19. Moreover, the gel strength (GS) was significantly increased, and the filtration properties were enhanced. The filtration volume was reduced by 10% from 5.0 to 4.5 cm3, and the filter cake thickness had a 37.5% reduction from 2.60 to 1.89 mm. The novelty of this study is highlighted by the introduction and evaluation of Claytone-IMG 400 as a new rheological additive for safe, efficient, and cost-effective drilling operations. The results indicate that Claytone-IMG 400 significantly improves the stability and performance of OBDFs, thereby reducing wellbore instability and drilling-related problems.

Development of a system for controlling a diamond drilling mode in terms of rock fault resistance

Relevance. Resistance to rock-cutting elements in rock destruction largely determines the effectiveness of drilling results. Information about the drag coefficient allows you to correctly and timely adjust the intensity of a drilling tool impact on the bottom of the well. To control the force contact of the drilling tool cutters with the bottom of the well, it is necessary to have a methodological apparatus that allows determining the rock destruction mechanism, taking into account the resistance forces. The existing methods for selecting combinations of diamond drilling mode parameters according to the known RPI index or according to the criterion of energy intensity of rock destruction N/vm , where N is the bottomhole power to overcome the resistance during rock destruction at the bottom hole; vm – mechanical drilling speed, have a number of disadvantages. They consist, for example, in occurrence of tool wear or the need to obtain a bottomhole power value in the current time mode, which is difficult under modern drilling conditions. Therefore, the study of rock resistance to destruction by a diamond cutter, based on application of the full factorial experiment method with obtaining mathematical models of factors and their graphical interpretation in combination with process control systems using computer technology in the current time mode, is a relevant topic. The disclosure of this topic will determine the direction of increasing technical and economic indicators of drilling. Aim. To develop a methodological apparatus that allows determining the mechanism of rock destruction taking into account the resistance forces to ensure optimal control of diamond drilling. Objects. Mechanism of rock resistance to destruction by a diamond cutter. Methods. Analysis, analytical research, full factorial experiment. Results. The paper presents an analytical analysis of the possibility of controlling drilling modes in order to achieve the greatest effect from drilling by estimating the drag coefficient as a function of the intensity of destruction or deepening per one revolution. Based on the analytical studies and the mode of drilling control by a computer in the real time mode, the authors have proposed a method for selecting the parameters of the drilling mode according to a given optimal value of the resistance index during drilling, and a way for its automatic implementation.

Research on Wellbore Stability in Deepwater Hydrate-Bearing Formations during Drilling

Marine gas hydrate formations are characterized by considerable water depth, shallow subsea burial, loose strata, and low formation temperatures. Drilling in such formations is highly susceptible to hydrate dissociation, leading to gas invasion, wellbore instability, reservoir subsidence, and sand production, posing significant safety challenges. While previous studies have extensively explored multiphase flow dynamics between the formation and the wellbore during conventional oil and gas drilling, a clear understanding of wellbore stability under the unique conditions of gas hydrate formation drilling remains elusive. Considering the effect of gas hydrate decomposition on formation and reservoir frame deformation, a multi-field coupled mathematical model of seepage, heat transfer, phase transformation, and deformation of near-wellbore gas hydrate formation during drilling is established in this paper. Based on the well logging data of gas hydrate formation at SH2 station in the Shenhu Sea area, the finite element method is used to simulate the drilling conditions of 0.1 MPa differential pressure underbalance drilling with a borehole opening for 36 h. The study results demonstrate a significant tendency for wellbore instability during the drilling process in natural gas hydrate formations, largely due to the decomposition of hydrates. Failure along the minimum principal stress direction in the wellbore wall begins to manifest at around 24.55 h. This is accompanied by an increased displacement velocity of the wellbore wall towards the well axis in the maximum principal stress direction. By 28.07 h, plastic failure is observed around the entire circumference of the well, leading to wellbore collapse at 34.57 h. Throughout this process, the hydrate decomposition extends approximately 0.55 m, predominantly driven by temperature propagation. When hydrate decomposition is taken into account, the maximum equivalent plastic strain in the wellbore wall is found to increase by a factor of 2.1 compared to scenarios where it is not considered. These findings provide crucial insights for enhancing the safety of drilling operations in hydrate-bearing formations.

Construction of an acoustic information transmission system of a horizontal directional drilling device

Currently, the constant growth in the volume of the horizontal directional drilling procedure dictates the improvement of the drilling technology and the technical requirements. One of the important technical requirements for the horizontal directional drilling device is the transmission of information about drilling parameters to the operator (depth, rotation angle, inclination angle). The solution to this problem is possible with the help of measuring systems installed inside the drilling head. Traditionally, in real drilling conditions, three communication channels are distinguished: electrically conductive, hydraulic and electromagnetic, each of which has some advantages and disadvantages. The use of acoustic waves excited in the internal space of the drilling head and propagating in the material of the drilling column to the receiver allows to eliminate the disadvantages of the listed communication channels and ensure the highest quality horizontal directional drilling procedure. The paper investigates the acoustic method of information transmission in a horizontal directional drilling device. An acoustic system for positioning a drilling tool has been developed, which provides the transmission of information about the coordinates of the drilling head. The acoustic channel of information transmission has been studied in terms of constructing its structural components: the design of the probe-transmitter (electromechanical transducer) has been developed, as well as the hardware of the system. In order to determine the requirements for the modulator-demodulator of signals of an acoustic information transmission channel, the propagation of an information package was simulated taking into account the resonant properties of the converter using the Multisim circuit simulation program. Thus, the use of an acoustic system for monitoring and transmitting information about the positioning of the drilling head makes it possible to abandon expensive contact methods for determining the position of the drilling head, which give point information and require a lot of time. The proposed acoustic information transmission channel allows for tight acoustic contact between the protective container and the drilling column to eliminate power losses, increases the efficiency of the device and reduces the loss of a useful signal during its propagation and also simplifies the operation of the device. As a result, the developed acoustic system provides an opportunity to perform the highest-quality horizontal directional drilling procedure with the necessary requirements for the volume of transmitted information and stability of operation in complex noise-signal conditions, which eliminates the disadvantages of previously used methods.

Hole formation mechanisms in double-sided laser drilling of Ti6Al4V-C/SiC stacked materials

This is the first investigation on the potential of doubled-sided laser drilling for hole making in Ti6Al4V-C/SiC, a hard-to-machine stacked structure that holds critical significance in high-temperature structural applications. While previous literature reported laser drilling-induced microstructural change in Ti6Al4V and C/SiC single sheets respectively, a comprehensive understanding of the melt pool formation process and its influence on hole morphology/quality is still lacking. The complexity increases when Ti6Al4V is coupled with C/SiC in a stacked structure, highlighting a significant yet understudied knowledge gap in understanding the intricate material interactions at the interface. Here we present a multifaceted study combining novel computational fluid dynamics (CFD) modeling approach with ablation mechanism investigation through advanced microstructure analysis. A hybrid CFD modeling strategy integrating volume of fluid method and level set method has been developed to successfully simulate the evolution of hole shape, recast layer formation, and melt pool flow behaviour in Ti6Al4V-C/SiC. This model provides comprehensive insights into molten pool dynamics under various laser drilling conditions, fostering a fundamental understanding of the mechanism that drives recast layer formation and influencing surface quality. To validate our modeling outcomes, extensive experimental investigations were undertaken across a range of laser drilling conditions. Whenever possible, samples were analysed using advanced materials characterization techniques, including scanning electron microscopy, energy dispersive spectroscopy, and electron backscatter diffraction, to elucidate the microstructural evolution within the recast layer and the formation of the heat-affected zone. Whenever possible, the results were also compared with single side drilled Ti6Al4V-C/SiC stacks, Ti6Al4V or C/SiC single sheets (i.e., the benchmark references). Our experimental findings align well with the modeling results, systematically illustrating that doubled-sided laser drilling of the stacked structure outperforms the conventional single-sided laser drilling in terms of hole morphology, surface roughness, and reduced recast layer formation. Despite these promising results, the proposed technology is currently limited to laboratory scales and lacks capacity in manufacturing certain parts with complex geometry. Future outlook has therefore been proposed with potential solution to address these challenges and enable real world applications in future.

Integration of advanced technologies to improve the efficiency of gas condensate field development

In the context of constantly growing global energy demand and rapid changes in the energy sector, the study and implementation of advanced technologies in the development of gas condensate fields is of critical importance. The purpose of this study is to investigate methods to increase the efficiency of production and sustainable use of energy resources by optimising the development of gas condensate fields using advanced technologies. The methods used include analytical method, classification, functional method, statistical method, synthesis. Within the framework of this study, the technological aspects of using wells of the Altyguyi gas condensate field were investigated and extensive laboratory and field analyses were conducted aimed at the correct implementation of the double injection method for simultaneous extraction of gas from one reservoir and oil from another, with an emphasis on their contribution to the development of wells through this approach. The paper also considers aspects of operation and technology, including hydrodynamic and thermohydrodynamic studies, when analysing well designs considering compatibility intervals and mining and geological drilling conditions, based on predictive curves of reservoir pressure and rock fracture pressure. As a result of the analyses, studies and calculations, the implementation of the method of intensification of gas condensate field production using the oil and gas approach of dual injection in one well was substantiated. This approach is focused on reducing capital investments and accelerating the development process. The practical significance of this research lies in the development and implementation of innovative technologies to optimise the production processes of gas condensate fields, which contributes to improving the efficiency of hydrocarbon production and promotes the sustainable use of energy resources

The influence of drilling-induced damages and hole quality on hoop tensile and fatigue behavior of CFRP tubes

Filament winding and roll wrapping methods are widely used in the production of composite tubes. While the mechanical behavior of composites produced by different methods may be different, the effects of the damages that occurred while machining composite tubes on the mechanical behavior may also be different. In this study, the effects of drilling-induced damages and hole quality on the tensile and fatigue strength of the filament-wound and roll-wrapped composite tubes were experimentally investigated. Results showed that while the behavior of the filament-wound composite tube under hoop tensile load is better than the roll-wrapped composite tube, the roll-wrapped tube performs better than filament-wound tube under hoop fatigue load. It was also observed that different drilling conditions affect the mechanical behavior of filament-wound tube while it was found that drilling conditions do not have a significant effect on the mechanical behavior of roll-wrapped tube because manufacturing defects are more dominant.

Submerged pulsating water jet erosion of ductile material

This article deals with the manifestations of erosion of statically acting concentrated multiple droplet impingements on materials over different lengths of time in order to assess the erosion evolution when the materials are submerged, as compared with the action of droplets on the materials under atmospheric conditions. The study aims to determine the extent of the erosive effects of droplets in underwater conditions. Experiments were conducted in a plastic pool in which the water level was varied from h = 80 to h = 120 mm to identify the effect of hydrostatic pressure at p120 = 0.1025 MPa and p80 = 0.1021 MPa. The results were compared with that of a control group of samples obtained under atmospheric air conditions. To observe the erosive damage evolution, 15 (n = 5) sites on the ductile materials EN AW-Al 99.5 and CW004A were exposed to high-intensity droplet impingement at defined exposure times. The exposure time varied from 0.125 s to 1.875 s, with increments of 0.125 s. As a droplet generator, an ultrasonic pulsating water jet with a frequency f = 20 kHz, a pressure p = 30 MPa and a nozzle diameter d = 0.4 mm was used to achieve the theoretical subsonic speed of the droplets. The results exceeded the assumptions regarding the possible attenuation of water pulses. It was found that under the theoretical speed of the jet vw = 225 m/s, the submerged condition causes attenuation in its erosive action. The incident area in the case of submerged treatment was more symmetrical. The erosion shift in term of prolonging incubation erosion stage was found to be a result of the increasing hydrostatic pressure. The results suggest that this method can also be used under submerged conditions for treatment or material drilling.

Real-time automatic identification methods for downhole whirling based on mechanical specific energy model of drill bit

In the drilling exploitation of hot dry rock for geothermal energy, whirling is one of the main low-efficiency conditions that affect the efficiency of Polycrystalline Diamond Compact (PDC) bit in horizontal well drilling. Realizing automatic and real-time identification with whirling is of great significance to save non-productive time and ensure drilling safety and benefit. In this paper, we first constructed a real-time drilling mechanical specific energy (MSE) model combined with while-drilling testing to reflect the real-time drilling conditions. The MSE model is used to normalize multi-source parameters. Secondly, we constructed a Back Propagation (BP) artificial neural network (ANN), and then the normalization effect verification, optimization of network parameters, and identification effect verification of whirling were carried out. The final results show that the established MSE model has a favourable effect on data normalization, which could also reduce the complexity of the required network model, and shorten the training time by 20–30 s/step. The optimal algorithm is Trainscg, whose optimal number of hidden layer nodes is 5, and the optimal maximum number of iteration steps is 1000. The established ANN model can accurately identify whirling based on MSE, the accuracy is about 0.94, and the average relative error is 1.3%. The method established in this paper provides a reference for the automatic identification of various low-efficiency conditions based on MSE.

Drilling Performance of Aluminum Plates under Manual Drilling Conditions

Drilling Performance of Aluminum Plates under Manual Drilling Conditions

Main stages of multi-hole well completion technology in PJSC TATNEFT implementation and ways of their improvement

As the main document in the development of multilateral well completion technology, a business plan is adopted, where technical problems are considered, due to the characteristics of the development object and the level of technology perfection. As an element of the technology, the technology of multilateral completion of wells under the conditions of equilibrium drilling and drilling using a flexible tubing string (coiled tubing) is considered. Keywords: multilateral well completion; horizontal well; development object; technical and economic effect; production characteristics; knowledge map; multidisciplinary team.

Impact of Pressure and Temperature on Foam Behavior for Enhanced Underbalanced Drilling Operations.

Foam, a versatile underbalanced drilling fluid, shows potential for improving the drilling efficiency and reducing formation damage. However, the existing literature lacks insight into foam behavior under high-pH drilling conditions. This study introduces a novel approach using synthesized seawater, replacing the conventional use of freshwater on-site for the foaming system's liquid base. This approach is in line with sustainability objectives and offers novel perspectives on foam stability under high-pH conditions. Experiments, conducted with a high-pressure, high-temperature (HPHT) foam analyzer, investigate how pressure and temperature affect foam properties. The biodegradable foaming agent ammonium alcohol ether sulfate (AAES) is employed. Results demonstrate that the pressure significantly impacts foam stability. Increasing pressure enhances stability, reducing decay rates and promoting uniform bubble sizes, especially at lower temperatures. This highlights foam's capacity to withstand high-pressure conditions. Conversely, the temperature plays a substantial role in foam decay, particularly at elevated temperatures (75 and 90 °C). Decreased liquid viscosity accelerates the liquid drainage and foam decay. While pressure mainly influences the AAES foam stability at temperatures up to 50 °C, temperature becomes the dominant factor at higher temperatures. Temperature's impact on foamability is minimal under constant pressure, maintaining consistent gas volume for maximum foam height. However, foam stability is sensitive to temperature variations, with increasing temperature leading to a more significant bubble size increase gradient. These findings stress the importance of considering temperature effects in foam drilling, particularly in deep and high-temperature environments. AAES foam exhibits stability at lower temperatures, making it suitable for surface and intermediate drilling. Understanding temperature-induced changes in foam structure and bubble size is essential for optimizing performance in high-temperature and deep drilling scenarios.

Reducing delamination risk with response surface methodology-supported drilling analysis for Nomex® aramid fiber composites

This article presents a comprehensive experimental investigation into the drilling behavior of Nomex®, a type of aramid fiber. The study specifically examines the impact of various cutting parameters and drill bit types on drilling outcomes. While Nomex® offers many advantages, difficult chip evacuation during drilling of aramid fiber composites can lead to surface defects and delamination. The research aims to explore how drilling parameters—such as spindle speed, feed rate—and four distinct drill bit types affect drilling performance. The analysis encompasses factors such as thrust force, torque, and surface roughness, studied under different drilling conditions and with various drill bit types. Moreover, the research assesses peeling and push-out delamination factors to gain insights into drill bit and coating characteristics. An examination of burr and chipping further enhances the comprehension of drilling performance. To determine the most effective drilling conditions, the study employs multi-response optimization. The optimal drilling performance is achieved with a combination of a 0.1 mm/rev feed rate, 1402.82 r/min spindle speed, and HSS-TiN drill type. This configuration successfully integrates responses, resulting in a composite desirability value of 0.95.

КОНТРОЛЬ НАПРУГИ ЗАНУРЮВАНИХ ЕЛЕКТРОДВИГУНІВ

The methods and means of voltage control on the clamps of submersible electric motors of electric drills are considered. The peculiarities of the submersible electric motor as a consumer of electrical energy when it is powered by three-phase voltage via a cable line with asymmetric electrical resistances of the phases are revealed. The main downhole factors influencing the functioning of the submersible electric motor that rotates the drill bit during drilling of deep oil and gas wells are analyzed. The impact of the temperature of the drilling fluid on the value of the active resistance of the cable cores and the drill pipe in deep drilling conditions has been updated. The results of the analysis of known technical solutions and concepts regarding the possibility of voltage control on the clamps of submersible motors, which would implement its physical measurement in industrial conditions, are presented. A method of analytically calculating the phase voltages on the clamps of the submersible electric motor of the electric drill, which is powered by an electric cable with asymmetric electric resistances of the phases, is proposed. The possibility of practical implementation of a laboratory installation based on the proposed method of calculating phase voltages on the clamps of the submersible electric motor of an electric drill is shown. For the practical implementation of the method of analytical calculation of phase voltages on the clamps of a submersible electric motor, the feasibility of using digital processing of signals from current and voltage transmitters located on the surface during oil or gas well drilling is substantiated. The advantages of the proposed method of controlling the voltage on the clamps of the submersible electric motor of the electric drill are the consideration of the electrical parameters of specific power supply cables obtained as a result of auxiliary measurements, and the possibility of technical implementation on a modern element base. The development and implementation of a device for monitoring phase voltages on the clamps of the submersible electric motor of an electric drill will increase the operational reliability and efficiency of drilling wells with an electric drill, which will reduce their cost.

An efficient drilling conditions classification method utilizing encoder and improved Graph Attention Networks

Identification of drilling conditions is paramount for ensuring safety and efficiency in drilling operations. Traditional methods, often based on manual analysis of drilling parameters and patterns by experts using empirical formulas, typically lack speed and precision in modern drilling procedures. To address this shortcoming, we have developed a sophisticated classification methodology that combines Encoder layers with improved Graph Attention Networks (GAT), aiming to precisely discern seven prevalent drilling conditions. Using an advanced expert empirical decision tree, we achieved superior accuracy in our dataset annotations. The model’s architecture integrates the K-nearest neighbors (KNN) algorithm for seamless integration between the Encoder layer and GAT networks. Sensitivity analyses pinpoint optimal feature parameters, leading to significant enhancements in model accuracy. Experimental outcomes show our annotation approach surpasses traditional techniques by 15.24%, achieving an accuracy of 96.73%. Additionally, our model boasts a recall rate of 94.22%, indicating high reliability in correctly identifying true positive drilling conditions, which is crucial for operational safety and decision-making in drilling scenarios. Characterized by its real-time capabilities, precision, and scalability, our model demonstrates promising potential for applications in practical drilling scenarios.

Design and Experiment of a Reconfigurable Bypass Downlink Surface Equipment for Transmitting the Surface Information to Deep Well

Abstract: In order to achieve the transmission of the control information from the surface to the downhole in the deep well during drilling, a design method of a new downlink surface equipment for generating negative pulse signals is presented in this paper. The equipment uses adjustable throttle control valve and pressure drop module (PDM) to realize bypass flow control. The PDM uses multistage variable nozzles to reduce drilling fluid pressure and meet drilling requirements under different pressure and flow rates. Design theory of the downlink surface equipment is established, and a specific design instance is given according to actual drilling conditions. Both laboratory and field experimental results verify the correctness of the proposed design method. The research results show that the design equipment can meet the needs of the transmission of the surface information, and the downlink transmission rate can reach at least one-bit data per 8 sec. The maximum pressure drop is realized by the PDM and the pressure drop at the control valve will be reduced according to drilling demand, the fluid velocity in the equipment is reduced as much as possible, the erosion of the drilling fluid to the equipment is reduced, and the service life can be improved effectively.

Machine learning for carbonate formation drilling: Mud loss prediction using seismic attributes and mud loss records

Due to the complexity and variability of carbonate formation leakage zones, lost circulation prediction and control is one of the major challenges of carbonate drilling. It raises well-control risks and production expenses. This research utilizes the H oilfield as an example, employs seismic features to analyze mud loss prediction, and produces a complete set of pre-drilling mud loss prediction solutions. Firstly, 16 seismic attributes are calculated based on the post-stack seismic data, and the mud loss rate per unit footage is specified. The sample set is constructed by extracting each attribute from the seismic trace surrounding 15 typical wells, with a ratio of 8:2 between the training set and the test set. With the calibration results for mud loss rate per unit footage, the nonlinear mapping relationship between seismic attributes and mud loss rate per unit size is established using the mixed density network model. Then, the influence of the number of sub-Gausses and the uncertainty coefficient on the model's prediction is evaluated. Finally, the model is used in conjunction with downhole drilling conditions to assess the risk of mud loss in various layers and along the wellbore trajectory. The study demonstrates that the mean relative errors of the model for training data and test data are 6.9% and 7.5%, respectively, and that R2 is 90% and 88%, respectively, for training data and test data. The accuracy and efficacy of mud loss prediction may be greatly enhanced by combining 16 seismic attributes with the mud loss rate per unit footage and applying machine learning methods. The mud loss prediction model based on the MDN model can not only predict the mud loss rate but also objectively evaluate the prediction based on the quality of the data and the model.

SELECTION OF DRILLING MUD TO PENETRATE COMPLICATED HORIZON S2V WATER INJECTION WELL AT NODA PRODUCTION SITE

Drilling wells under conditions of production from the S2V reservoir in the territory is a difficult task, which is associated with various technical and geological difficulties. These complications include increased well construction time and the potential for wellbore loss. The drilling process can disrupt the equilibrium of the rocks forming the walls of the well, especially in the case of complex clay formations. For successful drilling and risk minimization, special attention must be paid to the choice of drilling fluid and mud formulations. Various types of drilling fluids have been considered, including High Inhibition Systems (HPWBM) and Triple Inhibition Flushing Fluids, which contribute to improving drilling conditions in difficult geological conditions. Particular attention is paid to the drilling interval from 1650 to 2220 meters, which is represented by complex rocks, including limestones, mudstones and dolomitic areas with a porous structure. Potential problems such as caving, collapses, loss of drilling fluid, and differential sticking have been considered and mud formulations have been proposed to effectively combat these problems. To assess the impact of the solutions on the rocks, a study of the change in permeability of core samples was carried out using the permeability recovery factor. The results of the primary studies make it possible to make a preliminary conclusion on the compliance of the solution of smalllinous lime-inhibited with the necessary characteristics. Overall, this study highlights the importance of selecting the right mud formulations to ensure safe and efficient drilling of wells in challenging geological conditions.

TRANSPORTATION OF CUTTINGS BY DRILLING MUD IN HORIZONTAL WELLS. PART 1. MODELING THE STRUCTURE OF DISPERSED CURRENTS

Link for citation: Kharlamov S.N., Mehran Janghorbani, Zaykovskiy V.V. Transportation of cuttings by drilling mud in horizontal wells. Part 1. Modeling the structure of dispersed currents. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 34-48. In Rus. The relevance of the research is associated with the development of technical solutions for drilling wells with horizontal endings, in which cleaning the annulus from particles of drilled cuttings in hydraulic transport conditions seems technologically and economically efficient compared to other, for example, mechanical methods. The purpose of the article is to develop a computational methodology/approach to a detailed forecast and deep understanding of the physical mechanism of the influence of hydraulic transport on the well cleaning intensity. Moreover, the strategy of such a study is focused on the choice of flow conditions/rheological parameters of the model, in which the obtained detailed theoretical information on the evolution of the dynamic flow structure should be used in the development of design methods and the formulation of recommendations to engineering personnel for emergency warnings. The object of this study is a new class of viscous currents of dispersed media induced by external and internal forces, characteristic of the functioning of special equipment that ensures the movement of drilling mud with complex rheology in the well through an eccentric annular annulus. Results. The given article is the first part of the study devoted to solving complex problems accompanying the hydraulic transfer of rheologically complex mixtures through wells with an extended horizontal section and their cleaning from drilling cuttings. The first part presents the data on reasonable modeling of hydrodynamics of viscous dispersed mixture within the framework of reference to full equations describing laws of mass conservation, impulse for detection of peculiarities, determination of flow regularities in eccentric area of annular annulus, as well as search for ways of intensification of cleaning under conditions of real drilling. It is assumed that the viscous-inertial-gravitational flow of a liquid of the Herschel–Bulkly type with solid particles (sand) is carried out in conditions of laminar-turbulent, straight-flow and twisted (by the method of a movable wall) flow developing in the space. It is noted that the formation of modes with active and conservative action of external and internal forces allows efficient cleaning of the annulus. System of defining equations of mathematical model of hydrodynamics and mass transfer is analyzed for possibility of taking into account changes in nonlinearity of thermophysical properties, resistance to disturbances at boundaries of flow area and phase separation. It is noted that the prediction of molar processes is carried out within the framework of modern statistical models of the RANS method and the Euler–Lagrangian approach to describing the movement of heterogeneous media implemented in the ANSYS CFD software. It was shown that at the real drilling conditions, the mathematical model is successful in determining the spectrum of local and integral parameters of hydrodynamics and mass transfer in a wide range of changes in drilling conditions, which make it possible to understand the effects of particle sedimentation on the lower wall, the dynamics of vortex separation and the transfer of particles to the low-Reynolds region with a suspended state of the mixture structure and the inertial zone of the flow core. It is noted that the intensity of hydraulic transport downstream is significantly influenced by the conditions of phase entry, rheological characteristics of the mud. The calculations established the flow areas with satisfactory agreement of dynamic characteristics of the flow according to the proposed model with available experimental data, for example, shear stress at the wall, radial distributions of the components of the fluid velocity vector along the length of the well at different angles of deviation of its borehole from the vertical. Moreover, the results of this article should be taken into account when describing the data of the second part, as an addition to the study of hydraulic transport according to the proposed technique of real drilling of horizontal wells with optimal rheological properties of the mud.

Drilling Parameters Multi-Objective Optimization Method Based on PSO-Bi-LSTM

The increasing exploration and development of complex oil and gas fields pose challenges to drilling efficiency and safety due to the presence of formations with varying hardness, abrasiveness, and rigidity. Consequently, there is a growing demand for drilling parameter optimization and speed-up technologies. However, existing models based on expert experience can only achieve single-objective optimization with limited accuracy, making real-time adaptation to changing drilling conditions and formation environments challenging. The emergence of artificial intelligence provides a new approach for optimizing drilling parameters. In this study, we introduce the Bi-directional Long Short-Term Memory (Bi-LSTM) deep learning algorithm with the attention mechanism to predict the rate of penetration (ROP). This algorithm improves the ROP prediction accuracy to 98.33%, ensuring reliable subsequent optimization results. Additionally, we propose a coupling optimization algorithm that combines Bi-LSTM with the particle swarm optimization algorithm (PSO) to enhance drilling efficiency through parameter optimization. Our approach aims to maximize drilling footage while maintaining the highest ROP. The optimal solutions obtained are verified through multi-parameter cloud image analysis, yielding consistent results. The application of our approach demonstrates an 81% increase in drilling speed and a 28% reduction in drill bit energy losses. Moreover, the real-time optimization results effectively guide field operations.