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Accurately predicting the filtration volume (FV) in drilling fluid (DF) is crucial for avoiding drilling problems such as a stuck pipe and minimizing DF impacts on formations during drilling. Traditional FV measurement relies on human-centric experimental evaluation, which is time-consuming. Recently, machine learning (ML) proved itself as a promising approach for FV prediction. However, existing ML methods require time-consuming input variables, hindering the semi-real-time monitoring of the FV. Therefore, employing radial basis function neural network (RBFNN) and multilayer extreme learning machine (MELM) algorithms integrated with the growth optimizer (GO), predictive hybrid ML (HML) models are developed to reliably predict the FV using only two easy-to-measure input variables: drilling fluid density (FD) and Marsh funnel viscosity (MFV). A 1260-record dataset from seventeen wells drilled in two oil and gas fields (Iran) was used to evaluate the models. Results showed the superior performance of the RBFNN-GO model, achieving a root-mean-square error (RMSE) of 0.6396 mL. Overfitting index (OFI), score, dependency, and Shapley additive explanations (SHAP) analysis confirmed the superior FV prediction performance of the RBFNN-GO model. In addition, the low RMSE (0.3227 mL) of the RBFNN-NGO model on unseen data from a different well within the studied fields confirmed the strong generalizability of this rapid and novel FV prediction method. [ABSTRACT FROM AUTHOR]

Fractured and cavernous rocks, as well as rocks with increased permeability, are prone to mud losses during oil and gas well drilling. Circulation subs are a promising solution to mitigate mud and technological fluid losses in intervals ranging from 5 to 40 m3 /h by sealing the problematic interval. However, current circulation subs designs have notable drawbacks, including limited activation capabilities and usage scenario restrictions. This article provides a comprehensive analysis and characterization of the functional use of circulation subs, along with a qualitative comparative market analysis and patent search for devices activated by ball dropping, hydraulic, mechanical, and electromechanical means. The primary outcome of this research is the development of a functional hydraulic quick-acting activation device that addresses the shortcomings of existing designs. The device's design allow for future development of assemblies and optimization of their configurations to suit specific operating conditions. It can also serve as a protective measure for the downhole motor and telemetry system against harsh mechanical and chemical action during sealing. The device's limitations include pressure constraints and the need for flow rate adjustment. The article concludes with an overview of the developed hydraulically activated device and the results of qualitative bench tests, which demonstrate its functionality. [ABSTRACT FROM AUTHOR]

Phononic or acoustic bandgap materials have often been made using a polymer matrix with metal inclusions such as tin and steel, which have high densities compared to the matrix material. Acoustic bandgaps are observed when waves are not transmitted at certain frequencies. These have been applied in cavity resonators, acoustic waveguides, and more. This paper introduces a concept of using cement as the surrounding matrix and carbon nanotubes as the core inclusions to develop phononic materials. The exhibition of a bandgap makes it possible for the cementitious phononic material to be used as a sensor for cement cracking and defects in oil well bores. This paper discusses ways to optimize the characteristics of the carbon nanotube core to develop gaps in transmission spectra. It shows the behavior of the cementitious material with changing filling fraction, location of core cells, and surrounding defects, creating a pathway for paradigm-shifting non-destructive sensing technologies. [ABSTRACT FROM AUTHOR]

The research progress of deep and ultra-deep drilling fluid technology systematically reviewed, the key problems existing are analyzed, and the future development direction is proposed. In view of the high temperature, high pressure and high stress, fracture development, wellbore instability, drilling fluid lost circulation and other problems faced in the process of deep and ultra-deep complex oil and gas drilling, scholars have developed deep and ultra-deep high-temperature and high-salt resistant water-based drilling fluid technology, high-temperature resistant oil-based/synthetic drilling fluid technology, drilling fluid technology for reservoir protection and drilling fluid lost circulation control technology. However, there are still some key problems such as insufficient resistance to high temperature, high pressure and high stress, wellbore instability and serious lost circulation. Therefore, the development direction of deep and ultra-deep drilling fluid technology in the future is proposed: (1) The technology of high-temperature and high-salt resistant water-based drilling fluid should focus on improving high temperature stability, improving rheological properties, strengthening filtration control and improving compatibility with formation. (2) The technology of oil-based/synthetic drilling fluid resistant to high temperature should further study in the aspects of easily degradable environmental protection additives with low toxicity such as high temperature stabilizer, rheological regulator and related supporting technologies. (3) The drilling fluid technology for reservoir protection should be devoted to the development of new high-performance additives and materials, and further improve the real-time monitoring technology by introducing advanced sensor networks and artificial intelligence algorithms. (4) The lost circulation control of drilling fluid should pay more attention to the integration and application of intelligent technology, the research and application of high-performance plugging materials, the exploration of diversified plugging techniques and methods, and the improvement of environmental protection and production safety awareness. [ABSTRACT FROM AUTHOR]

By benchmarking with the iteration of drilling technology, fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and development difficulties of shale oil in the Jiyang continental rift lake basin, East China, the development technology system suitable for the geological characteristics of shale oil in continental rift lake basins has been primarily formed through innovation and iteration of the development, drilling and fracturing technologies. The technology system supports the rapid growth of shale oil production and reduces the development investment cost. By comparing it with the shale oil development technology in the United States, the prospect of the shale oil development technology iteration in continental rift lake basins is proposed. It is suggested to continuously strengthen the overall three-dimensional development, improve the precision level of engineering technology, upgrade the engineering technical indicator system, accelerate the intelligent optimization of engineering equipment, explore the application of complex structure wells, form a whole-process integrated quality management system from design to implementation, and constantly innovate the concept and technology of shale oil development, so as to promote the realization of extensive, beneficial and high-quality development of shale oil in continental rift lake basins. [ABSTRACT FROM AUTHOR]

Aiming at the problems of large load of rotation drive system, low efficiency of torque transmission and high cost for operation and maintenance of liner steering drilling system for the horizontal well, a new method of liner differential rotary drilling with double tubular strings in the horizontal well is proposed. The technical principle of this method is revealed, supporting tools such as the differential rotation transducer, composite rotary steering system and the hanger are designed, and technological process is optimized. A tool face control technique of steering drilling assembly is proposed and the calculation model of extension limit of liner differential rotary drilling with double tubular strings in horizontal well is established. These results show that the liner differential rotary drilling with double tubular strings is equipped with measurement while drilling (MWD) and positive displacement motor (PDM), and directional drilling of horizontal well is realized by adjusting rotary speed of drill pipe to control the tool face of PDM. Based on the engineering case of deep coalbed methane horizontal well in the eastern margin of Ordos Basin, the extension limit of horizontal drilling with double tubular strings is calculated. Compared with the conventional liner drilling method, the liner differential rotary drilling with double tubular strings increases the extension limit value of horizontal well significantly. The research findings provide useful reference for the integrated design and control of liner completion and drilling of horizontal wells. [ABSTRACT FROM AUTHOR]

Developments in ultradeep azimuthal resistivity (UDAR) technology has recently progressed from their application in high-angle and horizontal wells to low-angle and vertical wells. This has presented the opportunity to assess their suitability as derisking tools because of their ability to look ahead of the bit, up to c. 100 ft (c. 30.5 m). Dominated by a complex interplay of structure, sedimentation, and volcanic activity, the NE Atlantic Margin presents a challenging environment to plan and drill wells safely and within planned budget, with many wells drilled within the Faroe–Shetland Basin (FSB) currently the most expensive to-date within the United Kingdom continental shelf (UKCS). The limited number of wells drilled in the FSB and their geographical sparsity relative to those of other areas of the UKCS, make offset analysis and derisking a challenge. The often-unpredictable distribution of igneous rocks throughout the basin presents significant challenges in the planning and drilling of oil and gas wells. Up to 88% of igneous intrusions within the FSB are estimated to be below seismic resolution, which alongside variation in composition, presents significant issues related to drilling safely, efficiently and successfully. Within this paper, we investigate the use of UDAR technology and how they could be deployed in areas of complex volcanic geology such as the West of Shetland (WoS). This paper reviews the nature of the drilling experiences within the FSB to date, the impact it has on exploration, and how improvements in drilling technology could help decrease nonproductive time (NPT). [ABSTRACT FROM AUTHOR]

The investigation of drilling directional wells in the fields of western Turkmenistan is relevant at the present time, as it can contribute to the optimisation of hydrocarbon production processes in the region, increasing the efficiency and sustainability of production. The purpose of this study is to analyse and evaluate aspects of drilling directional wells in the fields of western Turkmenistan to determine their potential for increasing hydrocarbon production and reducing operating costs. Among the methods used, the analytical method, the classification method, the functional method, the statistical method, and the synthesis method etc., should be noted. The study is an extensive examination of the experience of drilling directional wells and cluster drilling in western Turkmenistan's oil and gas fields, which considers modern technological advances. Within the framework of this study, potential directions for the development of technology for drilling directional wells were considered, and recommendations were formulated on the use of specialised equipment and high-quality materials for cluster drilling in the south-western part of Turkmenistan. The use of modern technical solutions that meet international standards has led to the successful completion of cluster drilling of directional wells at fields in this region. This study is a substantial starting point for the future development of the technology of cluster drilling of deep directional wells, especially considering high reservoir pressures, and it contributes to the technical renewal and organisational restructuring of the cluster drilling process based on scientific research. The study on drilling directional wells has practical value, enabling the optimisation of the production of oil and gas resources in difficult geological conditions and increasing the efficiency of production in this region. [ABSTRACT FROM AUTHOR]

This document provides a calendar of upcoming events in the plastic film and sheeting industry, including conferences, symposiums, and webinars from September 2024 to March 2025. These events cover a wide range of topics such as coating science, foams, thermoplastics, additives, and sustainability. The document also includes information on process safety, including recent bulletins from the American Institute of Chemical Engineers and a report from the U.S. Chemical Safety Board on a fatal well blowout incident in Texas. The U.S. Chemical Safety and Hazard Investigation Board (CSB) is currently investigating two toxic chemical incidents in Louisiana in 2023, aiming to identify the causes and develop safety recommendations. DuPont has announced plans to separate its Water Solutions business into a standalone company, which focuses on providing clean water across various market segments. The separation is expected to be completed within 18 to 24 months and will not require a shareholder vote. The new company is expected to have a strong financial position and maintain an investment grade credit rating. [Extracted from the article]

Oil-based mud is widely used in shale oil well drilling because of its good stability and high temperature resistance at high temperature. However, during the drilling process of shale oil wells, fluid displacement between the annulus and the formation occurs. The existing temperature field model cannot predict the temperature distribution of the wellbore annulus under this condition. Based on the equations of heat conduction and conservation of energy, a new model of wellbore heat transfer in shale oil wells considering the displacement between downhole fluids is established in this paper. By comparing the temperature distribution of annular fluid under normal circulation, lost circulation and overflow, the accuracy of this model is confirmed. Taking the parameters of a shale oil well in a certain area as an example, the factors that affect the temperature of the annular fluid are analyzed and solved. Numerical analysis and simulation results show that the flow rate remains unchanged, and the annular temperature decreases by about 1.42 °C/L when the flow rate of the annulus increases. As the specific heat capacity of shale oil increases, the annular temperature increases by about 0.0012 °C/J/(kg·°C). In addition, when displacement between fluids occurs in the upper open-hole segment, there is an inflection point on the temperature distribution curve of the annular fluid, and the location of the inflection point is consistent with the location of the fluid displacement point. The results can provide a theoretical reference for drilling in complex formations with frequent formation-annulus fluid displacement, leakage and overflow. [ABSTRACT FROM AUTHOR]

Purpose. Development of highly effective composite diamond-containing materials based on WC‒Co matrices with CrB2 additives with improved mechanical and performance properties for creating matrices of rock-cutting tools for drilling oil and gas wells. Methodology. The assigned tasks were solved using a comprehensive research method, which includes a review and synthesis of literary sources; conducting analytical studies of existing composite diamond-containing materials; scanning electron microscopy (SEM) methods; X-ray phase analysis methods; calculation of experimental data by the Rietveld method, developed for the characterization of crystalline materials by powder X-ray diffraction; the Williamson-Hall technique. Findings. It has been established that the structure of the initial 94 %WC–6 %Co composite consists of WC phases with crystal lattice parameters a = 0.2906, c = 0.2837 nm and graphite with lattice parameters a = 0.2461, c = 0.6708 nm. The addition of chromium diboride to the composition of the 94 %WC–6 %Co sample leads to the decomposition of the CrB2 phase and the formation of the final phase composition: WC + B2CoW2 + Cgraphite + solid solution of tungsten and carbon in cobalt. Originality. It was shown for the first time that if the WC–6Co system is characterized by insignificant solubility of the components in each other, then in the WC–Co–CrB2 system there is a significant mutual dissolution of the components, which leads to a decrease in their sizes during the sintering process. When the threshold concentration (~4 %) of chromium diboride in the charge is reached, phases of the hexagonal WC group and new phases of the orthorhombic group B2CoW2 and amorphous carbon inclusions begin to form in the structure of the composite. Practical value. A highly effective composite diamond-containing material based on WC‒Co matrices with CrB2 additives with increased mechanical (hardness, crack resistance, compressive and bending strength) and operational (wear resistance, productivity) properties has been developed to create a highly effective rock-cutting tool for drilling oil and gas wells. [ABSTRACT FROM AUTHOR]

The stability analysis of horizontal wells is essential for a successful underground coal gasification (UCG) operation. In this paper, a new 3D coupled thermo-mechanical numerical modeling is proposed for analyzing the stability of UCG horizontal wells. In this model, the effect of front abutment stresses, syngas pressure, syngas temperature and thermal stresses is considered to predict the mud weight window and drilling mud pressure during UCG process. The results show that the roof caving in UCG panel has a greatest impact on the stability of horizontal well. Moreover, when the time of coal gasification is increased, the well convergence increases and for more stability it is necessary to increase the drilling mud pressure. This research was carried out on the M2 coal seam in Mazino coal deposit (Iran). The results showed that the mud weight window for horizontal well drilling is between 0 and 33 MPa. The appropriate stress for the maximum stability of the horizontal well, taking all the thermal and mechanical parameters into account, is 28 MPa. The suggested numerical method is a comprehensive and consistent way for analyzing the stability of horizontal wells in UCG sites. [ABSTRACT FROM AUTHOR]

The results of a reconnaissance survey using direct-prospecting technology of satellite images and photographs frequency-resonance processing within some areas of coal basin and shale gas production in China, France, Ukraine, USA, Argentina, England, UAE are presented. The data of the local areas reconnaissance surveying within coal basins show the possibility of detecting oil, condensate and gas deposits in the deep and ultra-deep horizons of cross-section underneath coal deposits. Materials of experimental studies at the Fuman oil field site and the Luntan-1 deep well drilling site indicate the potential possibility and feasibility of direct-prospecting methods using in the process of selecting the most optimal sites of the deep exploratory wells for oil and gas drilling. Helium deposits may be discovered at an ultra-deep well drilling site in the Taklamakan Desert at depths of over 7120 m. By detailed scanning of this cross-section interval, the depths of helium accumulations in the reservoirs can be determined. The deep channels for fluids, chemical elements and minerals migration, filled with 1-6 groups of sedimentary rocks, were found in all surveyed shale gas production sites. The received measurement data of the work carried out can be considered as additional evidence in favor of the concept of deep (abiogenic) synthesis of hydrocarbons, including those in shale formations. Within the survey site in England a significant number of local zones of visible hydrogen degassing are located. It is advisable to conduct additional research on these sites in order to study these local zones in more detail. Experimental studies within area of shale oil in the Williston Basin also confirmed the presence of hydrocarbon deposits in the deep horizons of cross-section. It is advisable to carry out detailed geological exploration work in order to search for hydrocarbon deposits in coal and shale basins in various regions of the world! To the east of Williston Basin, a large cluster of basalt volcanic structures with hydrogen and living (healing) water, as well as the process of hydrogen and phosphorus migration into the atmosphere were revealed by instrumental measurements. In general, the materials of the experimental work carried out can be considered as additional evidence in favor of the volcanic model of formation of structural elements and the external appearance of the Earth's surface, as well as deposits of ore and combustible minerals and water. The research results indicate the feasibility of using mobile technology of frequency-resonance processing and decoding of satellite images and photographs for the detection and localization of oil and gas accumulation zones within large blocks and local areas. The use of super-operational and low-cost directprospecting technology will significantly speed up the exploration process for oil, gas, natural hydrogen and ore minerals, as well as reduce the financial costs of its implementation. [ABSTRACT FROM AUTHOR]

In the drilling of oil wells, the need to accurately detect downhole formation pressure transitions has long been established as critical for safety and economics. In this article, we examine the application of Hidden Markov Models (HMMs) to oilwell drilling processes with a focus on the real time evolution of downhole formation pressures in its partially observed state. The downhole drilling pressure system can be viewed as a nonlinear, non‐degrading stochastic process whose optimum performance is in a region in its warning state prior to random failure in time. The differential pressure system (∆P)$$ \left(\Delta P\right) $$ is modeled as a hidden 3 state continuous time Markov process. States 0 and 1 are not observable and represent the normally pressured (initiating ∆P$$ \Delta P $$) and abnormally pressured or warning (reducing ∆P$$ \Delta P $$) states respectively. State 2 is the observable failure state (from negative ∆P$$ \Delta P $$ and loss of well control). The signal process of the evolution of differential pressure (∆P)$$ \left(\Delta P\right) $$ is identified in the changes in the observable rate of penetration (ROP) encoded in drilling performance data. The state and observation parameters of the HMM are estimated using the Expectation Maximization (EM) algorithm and we show, for a univariate system with a depth dependent time relationship, that the model parameter updates of the EM algorithm equation have explicit solutions. A Bayesian inference model, to determine the safety threshold of the system and early failure prediction at each sampling epoch, is thereafter proposed. The application of our stochastic model of the dynamic evolution of downhole pressures in operational time is illustrated with a hindcast case example. The analysis showed strong early indication of probable failure in real time and was validated in the field post drilling system failure that resulted in significant recovery costs. The potential to predict the differential pressure state transitions ahead of the bit represents a capability not currently available in the industry. This opens up significant opportunity for value creation from optimizing drilling operations to deliver substantial savings in well construction costs. [ABSTRACT FROM AUTHOR]

High-precision tapered threads are widely used in hard-loaded mechanical joints, especially in the aggressive environment of the drilling of oil and gas wells. Therefore, they must be made of workable materials often difficult to machine. This requires the use of high-performance cutting tools, which means the application of non-zero geometric parameters: rake and edge inclination angles. This study is based on analytical geometry methodology and describes the theoretical function of the thread profile as convoluted surfaces dependent on the tool's geometric angles. The experiments were conducted using a visual algorithm grounded on the obtained function and prove the practical use of the scientific result. They predict the required accuracy of thread made using a lathe tool with a rake angle of up to 12°. [ABSTRACT FROM AUTHOR]

This paper presents a novel method to improve drill pressure measurement accuracy in slim-hole drilling within the petroleum industry, a sector often plagued by extreme conditions that compromise data integrity. We introduce a temperature compensation model based on a Chaotic-Initiated Adaptive Whale Optimization Algorithm (C-I-WOA) for optimizing Convolutional Neural Networks (CNNs), dubbed the C-I-WOA-CNN model. This approach enhances the Whale Optimization Algorithm (WOA) initialization through chaotic mapping, boosts the population diversity, and features an adaptive weight recalibration mechanism for an improved global search and local optimization. Our results reveal that the C-I-WOA-CNN model significantly outperforms traditional CNNs in its convergence speed, global searching, and local exploitation capabilities, reducing the average absolute percentage error in pressure parameter predictions from 1.9089% to 0.86504%, thereby providing a dependable solution for correcting temperature-induced measurement errors in downhole settings. [ABSTRACT FROM AUTHOR]

Mud loss is the most serious formation damage in oil and gas well drilling engineering and is an unsolved technical problem. To prevent mud loss, it is necessary to accurately understand and identify three key factors of mud loss, including the location of the loss, the time of occurrence, and the severity of the loss. The diagnosis of mud loss is a prerequisite for the proper formulation of mud loss control techniques. It emphasizes the integration of predrilling, drilling, and postanalysis information to describe and characterize loss zones and predict potential loss zones. On the basis of the theory of engineering fuzzy mathematics, we develop a mathematical model for loss probability evaluation that combines logging anomaly features and engineering data to predict the location of losses from drilling mud and develop a loss formation identification method. The study of hydraulic fracture deformation through stress‐sensitive experiments and numerical simulations can predict the deformation and severity of loss channels, which can help optimize the loss of circulating material by adding drilling fluid. Loss pressure models have been developed based on mud loss mechanisms, and loss pressure for hydraulic fracture creation, connection, and extension has been studied to help identify loss mechanisms and types. Mud losses can be identified by unusual engineering characteristics, including sudden changes in drilling times, cuttings, and mud logging. Real‐time logging parameters can be used to monitor the loss process and hence predict the loss trend. The framework of loss diagnosis techniques is established, which helps in successful mud loss controlling. [ABSTRACT FROM AUTHOR]

Noise from oil and gas development is pervasive across many landscapes and creates a novel soundscape that wildlife must adapt to or avoid. In response to anthropogenic noise, many wildlife species alter their vocalizations. Some adjusted vocalizations may promote effective communication in the presence of noise by improving detection and preserving information about the sender's status. However, if adjusted vocalizations fail to improve communication in noise, both missed detections and misinterpretations of vocalizations could impact the fitness of individuals and ultimately contribute to population declines. Baird's sparrow is a species at risk in Canada that adjusts its songs in response to oil well drilling noise by altering whole-song elements such as decreasing the peak frequency of songs (Curry et al., 2017, Bioacoustics, 27 (2), 105–130). We examined the efficacy of these adjusted songs in the mixed-grass prairies of southern Alberta, Canada during the Baird's sparrow breeding season (May–July 2018 and 2019) using a repeated measures study design (N = 69 dyads) in which we simulated territorial intrusions by broadcasting adjusted songs and unadjusted songs in the presence and absence of oil well drilling noise recordings. We found that focal male behaviour was mainly mediated by noise treatment when compared to song treatment. In noisy trials, males sang less, called more and performed more flybys, regardless of song treatment type. However, in noisy trials, males displayed longer song latency in response to unadjusted songs compared to adjusted songs. The results of our novel study suggest that the presence of oil well drilling noise elicits more aggressive territorial defence behaviour in Baird's sparrows or hinders the ability of individuals to locate or assess rivals. Additionally, our results suggest that adjusted songs only partially restore effective communication in noise. • Focal male behaviour was mainly influenced by the presence or absence of noise. • Noise may have caused increased aggression or impaired detection in focal males. • Focal males did not generally discriminate between adjusted and unadjusted songs. • Adjusted songs may partially improve acoustic detection in noise. • Unadjusted songs may experience partial acoustic masking in noise. [ABSTRACT FROM AUTHOR]

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This study targeted to investigate a type of excavation slurry by local available material in Najaf region. On the other hand, chief practises is supported the deep sides of foundation in particular pile foundation and, drilling oil wells. The results of slurries are checking, for seven properties, which includes the viscosity (apparent plastic and funnel Marsh), yield stress, density, acidity, and gel power (10–0 min). Which are 11.7367, 8.8733, 38.1667, 11.5467 mPa·s, 1.1045 kg m−3, 10.9067, and 11.2683 mPa·s, respectively. On the basis of the results tests for the above properties, that is possible to produce a product that conforms to the specifications of American Petroleum Institute specifications, and according to the requirements of the standard ACI 336.3R-93:2006 without additives. The rheological behavior improvement is achieved through the breakdown of the bundles of palygorskite fibers that normally make up the texture of these mudstones by increasing the time and speed of the shear force as soon as increasing the concentration of clay powder. [ABSTRACT FROM AUTHOR]

This paper presents a coupled computational fluid dynamics–discrete element method (CFD–DEM) simulation to predict cuttings transport by the drilling fluid (mud) in different oil well drilling conditions. The mud rheology is expressed by the Herschel–Bulkley behaviour and modelled in a Eulerian framework (CFD), while the cuttings are modelled using the Lagrangian approach (DEM). In this work, the effects of drill string rotation, inclination angle, cutting size, mud rheology, and annular velocity on cleaning efficiency are investigated. It is found that increasing the well deviation from vertical to horizontal leads to a higher cuttings concentration. However, at low annular velocity, the cuttings concentration for the inclined (45-degree) annulus is found to be higher than the horizontal one due to the sliding motion of cuttings on the lower section of the annulus. Overall, the drill pipe rotation has little effect on decreasing the cuttings concentration, but the effect is more pronounced at low annular velocity. [ABSTRACT FROM AUTHOR]

In the present study, three different depth conversion methods have been used with varying equations at Mishrif Formation to determine the best method to produce better, more realistic and accurate interpretation results and to reduce the risk of future petroleum production wells drilling. Three horizons were picked (Tanuma, Mishrif and Rumaila) and converted into a two-way time grid surface. In addition, the velocity parameters (instantaneous velocity and rate of velocity change with depth) were computed and converted to the form grid surface from the well data, showing lateral velocity variation. Among the three models carried out, the Model 1 is considered the most accurate depth conversion method in this region according to the results of the geostatistical analysis. This method gave fewer errors and mistakes between actual and predicted depth with the best intra-extrapolation technique at all directions away from the well area with a standard deviation value of 13.2, and the standard deviation values of 13.6 and 13.9 for models 2 and 3, respectively. [ABSTRACT FROM AUTHOR]

[Objective] In recent years, high-yield gas wells, such as those in eastern Sichuan, Tarim Oilfield, and Dongfang Gas in the South China Sea, have been increasingly common. However, these wells are not without their challenges. The production pipe string of Sangao gas wells is prone to vibration failure due to the impact of high-speed gas. Taking the Kuqa high-pressure gas area of the Tarim Oilfield as an example, 19 failure incidents have been recorded out of 15 wells, resulting in huge economic property losses and, regrettably, casualties. The primary cause of these failures has been identified as the excessive dynamic load caused by pipe string vibration. Therefore, understanding the vibration characteristics of the production pipe string has become a crucial study area. The production string in oil and gas wells possesses its unique characteristics. Its large slenderness ratio results in a very low overall stiffness, which is difficult to simulate in a typical small experimental system. [Methods] In this study, we established a test bench for large production string evaluation. We developed an extensive, elongated string model using Polyethylene pipe to replicate the vibration characteristics of the production string under high-speed fluid impact. [Results] The experimental results show that the production string in Sangao gas wells vibrates at a constant frequency under the influence of a high-speed fluid. The vibration amplitude is most pronounced in the middle and bottom parts of the string. It was also observed that an increase in gas yield correlates with an increase in the severity of the pipe column's vibration. An effective method of curtailing this vibration amplitude involves increasing the wall thickness of the tubing. However, it is important to note that while this may reduce the tubing amplitude, it does not change the vibration frequency of the tubing string. The packer installation position also plays a pivotal role in vibration suppression. If the packer is installed too high or too low, it fails to effectively suppress vibration. The optimal placement for a single packer has been found to be at the 8/10 position of the string, where it can efficiently suppress vibration. This paper further delves into the analysis of displacement, frequency, and vibration characteristics of simulated tubing when subjected to a high-speed fluid within the tubes. [Conclusions] This study further explores the effects of pipe wall thickness, gas yield, and packer setting positions on the vibration characteristics of simulated tubing. The following conclusions were drawn from the research. When the fluid Reynolds number within the tube reaches 21 430, the simulated tubing presents a second-order vibration mode. This results in a substantial amplitude in the middle and bottom sections of the simulated tubing, which are prone to contact and collision with the casing wall, potentially resulting in pipe string failure. The wall thickness of the tubing exerts little effect on the vibration frequency of the simulated tubing. However, it significantly affects the vibration amplitude. The thicker the tubing, the smaller the vibration amplitude of the simulated tubing. Therefore, tubing vibration can be effectively suppressed by increasing tubing thickness during the actual production process. The larger the gas production, the greater the frequency and amplitude of the simulated tubing vibration. When gas production is excessively large, the tubing is likely to collide severely with the casing wall, thereby increasing the risk of tubing failure. Therefore, it is crucial in the actual production process to determine the daily gas output reasonably, keeping in mind the bearing limit of the tubing. Packers suppress string vibration by limiting the lateral displacement of the string. Installing multiple packers proves to be more effective than a single packer in suppressing vibration. [ABSTRACT FROM AUTHOR]

The field of nanotechnology has shown promise in addressing major problems and improving drilling effectiveness. An overview of the difficulties encountered during oil and gas well drilling operations and the demand for creative solutions opens the debate. This review explores how nanotechnology is transforming the oil industry and enhancing performance as a whole. The evaluation of the uses of nanotechnology for better oil recovery, real-time monitoring, innovative materials, drilling fluids, and reservoir characterization are extensively discussed in this review. The primary function of additives is to improve the fundamental characteristics of drilling fluids. The variety of fluid additives available is a reflection of the complex drilling–fluid systems that are currently being used to enable drilling in increasingly difficult subsurface conditions. Common additives used in water- and oil-based drilling fluids include lubrication, shale stability, filtration control, rheology control, viscosification, and pH regulation. Drilling fluids frequently contain filtration control additives such as starch, polyanionic cellulose (PAC), carboxymethyl cellulose (CMC), and nanoparticles (NP). Commonly used rheology-modifier additives are xanthan gum, carboxymethyl cellulose, guar gum powder, and, more recently, salt-responsive zwitterionic polymers that were used as viscosifiers to water-based drilling fluids. The three main additives that regulate pH are citric acid monohydrate, potassium hydroxide, and sodium hydroxide. Additives that stabilize shale, such as potassium and sodium salts and asphaltenes, are often used. A wide range of materials are included in the category of lubricating additives, including polymers, asphaltenes, glass beads, oils of various grades, and oil-surfactants. Various fibrous materials, including wood, cotton, fibrous minerals, shredded tires from vehicles, and paper pulp, are used as additives to control circulation. Furthermore, shredded cellophane, bits of plastic laminate, plate-like minerals like mica flakes, granulated inert materials such as nut shells, and nano-polymers are used in wellbores to reduce fluid loss. The incorporation of nanoparticles into drilling fluids has produced upgraded fluids with better features, including improved lubricity, thermal stability, and filtering capacities. These developments aid in lowering friction, enhancing wellbore stability, and enhancing drilling efficiency. This paper also emphasizes how nanotechnology has made enhanced drilling equipment and materials possible. Drilling equipment's longevity and performance are increased by nanocomposite materials that have been reinforced with nanoparticles due to their improved mechanical strength, wear resistance, and thermal stability. Advanced reservoir characterisation tools, including nanoparticle tracers and nanoscale imaging methods, can help locate the best drilling sites and increase production effectiveness. On the other hand, nanofluids and nanoemulsions can potentially increase oil recovery because they enhance fluid mobility, lower interfacial tension, and alter rock wettability. Although nanotechnology has many advantages, there are also issues that need to be resolved. For an implementation to be effective, factors including nanoparticle stability, dispersion, and potential environmental effects must be carefully taken into account. This review highlights the need for future research to create scalable manufacturing procedures, improve nanoparticle behaviour, and determine nanomaterials' long-term environmental effects. In conclusion, this in-depth analysis illustrates the use of nanotechnology in transforming the process of drilling oil and gas wells. [ABSTRACT FROM AUTHOR]

Currently, drilling of directional oil and gas wells under complex technical-technological and mining-geological conditions requires the use of drill pipes made of various materials. In turn, to choose rational modes of strengthening drill pipes and drill string layouts, information on the contact forces and friction forces of the drill string pipes on boreholes is necessary. Drill pipe curved sections friction with boreholes and drill bit resistance moment changes are the main causes of uneven rotation of a drill string during rotary or combined drilling methods and the occurrence of parametric oscillations. To reduce the cost of mechanical energy for well wiring, it is necessary to take into account the "drill string–borehole rocks" force interaction to estimate the magnitude of the frictional forces and their influence on the technological parameters of the drilling process. To solve this problem, mathematical models of "conventionally vertical and inclined drill string sections–borehole" were built. Based on the industrial data, an analysis of the force interaction of a deformed drill string composed of pipes made of different materials (aluminum, titanium, steel) was carried out. Analytical dependences were obtained for determining the contact forces and friction of the pipes on boreholes. A numerical study of the change of these power factors depending on the depth of the well under conditions of intensive vibration loading was carried out. The amplitude values of these forces, the frequency of their change for good sections, as well as the places for the most rational installation of drill pipes in the layout of the drill string were estimated. It was established that the intensity of contact and friction forces for steel drill pipes is greater than for titanium or aluminum ones. It is shown that the greater impact of a solid steel string on contact forces and frictional forces compared to a layout with sections of titanium or aluminum pipes in the range of vibration frequencies of 8–22 Hz corresponds to a bit rotation frequency of 70–80 rpm. The practical application of the obtained research results will contribute to the improvement of technical and economic indicators of the well drilling process. [ABSTRACT FROM AUTHOR]

Well deviation is a prevalent problem in deep oil and gas exploration, leading to a significant increase in drilling costs. The conventional bottom-hole assembly (BHA) anti-deviation design method does not consider the impact of the BHA structure on lateral vibration. This paper proposes an integrated BHA design method that takes into account both anti-deviation and vibration reduction. This method evaluates the BHA's anti-deviation ability using the drilling trend angle. A negative value of the drilling trend angle indicates that the BHA can correct well deviation. A finite element linearized dynamics method is used to evaluate the lateral vibration intensity of the BHA. This method involves calculating the bending displacement caused by mass imbalance and then determining the magnitude of the bending strain energy based on this displacement. The structural factors affecting the anti-deviation ability and potential lateral vibration intensity of pendulum BHAs and bent-housing mud motor (BHMM) BHAs were studied, and field tests were conducted for verification. The research shows that for pendulum BHAs, the factor that has the greatest impact on anti-deviation ability and vibration intensity is the distance from the stabilizer to the drill bit. For BHMM BHAs, the length of the short drill collar has a significant impact on the vibration intensity. Compared with current design methods, the mechanical specific energy (MSE) of the single stabilizer pendulum BHA decreased by 12%, while the MSE of the BHMM BHA decreased by 26.4%. Both decreases indicate a reduction in vibration intensity. This study will help to further increase drilling speed while preventing well deviation. [ABSTRACT FROM AUTHOR]

Efficient hole cleaning during drilling operations is critical to maintain a high rate of penetration and smooth drilling, leading to minimum drilling problems and economical drilling efficiency. This process involves several important factors, including pipe-sticking incidents, higher cuttings concentrations in the annulus, noisy vibration of the drill string, erratic equivalent circulating density, lost circulation incidents, well control incidents, geomechanical hole section instability, tight spots during tripping operations, and excessive usage of chemical additives for conditioning hole sections and mud. Various approaches, including correlations, methodologies, developments, algorithms, equipment, charts, field experience, chemicals, and studies involving experiments, can be used to enhance the efficiency of hole cleaning. The development of hole-cleaning models is important for use as hole-cleaning indicators to ensure optimized drilling efficiency. This paper presents a comprehensive overview of the complex field of hole cleaning in the oil and gas industry. It includes techniques, tools, models, and chemical additives. It also encompasses drilling engineering, operations, and chemistry. To facilitate the transit of drill cuttings, maintain hole section stability, cool and lubricate the drill bit, and transmit hydraulic horsepower, this article outlines the important roles of drilling fluids. The significance of chemical additives, including nanoparticles, natural and modified polymers, and synthetic polymers, in preserving wellbore stability, improving drilling efficiency, and lowering drill bit wear is also covered in the study. It concludes by making recommendations for further study to clarify hole cleaning for the reader to facilitate and boost drilling efficiency. [ABSTRACT FROM AUTHOR]

Sparse and limited well data in oil fields pose challenges in accurately estimating petrophysical properties for reservoir characterization. Conventional Machine Learning (ML) models often struggle to provide accurate estimations in such scenarios. This paper presents an ensemble modeling solution, named "SEMoRC", which effectively predicts various log (petrophysical) properties using seismic data, when the conventional models fail to achieve it. The model architecture in the ensemble is dynamically determined at runtime to build an optimized ensemble of ML models. The proposed approach has been applied to a real-world dataset and has shown superior performance in terms of root mean square error (RMSE) and correlation coefficient (CC), compared to its constituent ML models. Our analysis conducted on different log properties demonstrates the efficacy of the proposed approach and its potential in enhancing reservoir characterization with sparse and limited oil wells, and hence can facilitate decision-making in oil well drilling. [ABSTRACT FROM AUTHOR]

Aiming at the problems of high drilling friction and serious backing pressure on the drill string under the difficult oil and gas drilling conditions, which leads to low rate of penetration(ROP) or low rock-breaking efficiency, this article proposed a non-moving component jet oscillation tool based on the Coanda effect. Combined with the field working conditions of drilling process, the numerical simulations of the oscillation nipple internal flow are completed first. After that, the recirculation characteristics, switching mechanism and entrainment effect of the internal fluid are studied, including the flow velocities and the dynamics features of the pressure field at different positions. The experimental tests are conducted to verify the theoretical study results. The results show that the fluid presents same periodic wall-attached and switching behaviors. With the inlet flow increasing, the fluid velocities at the inlet and outlet locations show quasi-linear distributions, and the fluid pressures loss changes periodically. The jet oscillation tool can generate appropriate periodic pressure pulse, and the pulse value and fluid switching period are determined by design parameters. The comparative analysis between numerical simulations and experimental tests shows the results exhibit similar characteristics. It is concluded that this non-moving component tool can produce periodic oscillation effect, thereby changing the friction status between the drilling tools and wellbore and improving drilling efficiency. The research results can provide references for optimization designs of similar downhole tools and also develop technical supports for the efficient exploitation of oil and gas resources. [ABSTRACT FROM AUTHOR]

The brittleness index plays a significant role in the hydraulic fracturing design and wellbore stability analysis of shale reservoirs. Various brittleness indices have been proposed to characterize the brittleness of shale rocks, but almost all of them ignored the anisotropy of the brittleness index. Therefore, uniaxial compression testing integrated with geophysical logging was used to provide insights into the anisotropy of the brittleness index for Longmaxi shale, the presented method was utilized to assess brittleness index of Longmaxi shale formation for the interval of 3155-3175 m in CW-1 well. The results indicated that the brittleness index of Longmaxi shale showed a distinct anisotropy, and it achieved the minimum value at β = 45°-60°. As the bedding angle increased, the observed brittleness index (BI2_β) decreased firstly and increased then, it achieved the lowest value at β = 40°-60°, and it is consistent with the uniaxial compression testing results. Compared to the isotropic brittleness index (β = 0°), the deviation of the anisotropic brittleness index ranged from 10% to 66.7%, in other words, the anisotropy of brittleness index cannot be ignored for Longmaxi shale. Organic matter content is one of the main intrinsic causes of shale anisotropy, and the anisotropy degree of the brittleness index generally increases with the increase in organic matter content. The present work is valuable for the assessment of anisotropic brittleness for hydraulic fracturing design and wellbore stability analysis. [ABSTRACT FROM AUTHOR]

The majority of published empirical correlations and mechanistic models are unable to provide accurate flowing bottom-hole pressure (FBHP) predictions when real-time field well data are used. This is because the empirical correlations and the empirical closure correlations for the mechanistic models were developed with experimental datasets. In addition, most machine learning (ML) FBHP prediction models were constructed with real-time well data points and published without any visible mathematical equation. This makes it difficult for other readers to use these ML models since the datasets used in their development are not open-source. This study presents a white-box adaptive neuro-fuzzy inference system (ANFIS) model for real-time prediction of multiphase FBHP in wellbores. 1001 real well data points and 1001 normalized well data points were used in constructing twenty-eight different Takagi eSugeno fuzzy inference systems (FIS) structures. The dataset was divided into two sets; 80% for training and 20% for testing. Statistical performance analysis showed that a FIS with a 0.3 range of in- fluence and trained with a normalized dataset achieved the best FBHP prediction performance. The optimal ANFIS black-box model was then translated into the ANFIS white-box model with the Gaussian input and the linear output membership functions and the extracted tuned premise and consequence parameter sets. Trend analysis revealed that the novel ANFIS model correctly simulates the anticipated effect of input parameters on FBHP. In addition, graphical and statistical error analyses revealed that the novel ANFIS model performed better than published mechanistic models, empirical correlations, and machine learning models. New training datasets covering wider input parameter ranges should be added to the original training dataset to improve the model's range of applicability and accuracy. [ABSTRACT FROM AUTHOR]

The growing popularity of unconventional wells has led to increased interest in assessing and predicting their production performance. These wells, with their extended-reach structures, are able to generate and access larger reservoir volumes. Therefore, understanding the impact of a well's lateral trajectory on its transient production performance is crucial. This study investigates the effect of lateral-trajectory undulation amplitude on flow behavior based on the experimental results obtained at the University of North Dakota using an undulated two-phase (UTP) flow loop. The experiments involved injecting an air-and-water mixture through a section with variable undulation amplitude followed by a vertical section. The results revealed that the increasing undulation amplitude resulted in lower translational velocity, frequency, and length, with consistent slug acceleration along the system profile. Additionally, the frequency of slugs decreased as they traveled through the vertical section. The measured data indicated that higher undulation amplitudes led to increased horizontal pressure losses and variability, suggesting larger instabilities. The numerical simulations predicted lower translational velocity and frequency, longer slug length, and similar vertical pressure losses when compared to the experimental results. [ABSTRACT FROM AUTHOR]

The occurrence of buoyancy-driven flow and reactive solute transport in a fluid-saturated porous medium can be induced by either natural processes or human activities. Typical examples include the groundwater salinization in carbonate-rock aquifers and the acid treatment of oil wells in petroleum drilling industry. In this paper, the classical Elder problem of buoyancy-driven convection in two-dimensional porous media is extended to include the local chemical interactions between the solute in the pore liquid (e.g. salt such as NaCl or acids such as HCl and HCl/HF mixtures) and the solid space of the porous medium (e.g. minerals such as calcite and dolomite). Effects of the geochemical processes on the flow and mass transport are investigated. For the reactive, strongly solute-driven case in the regime dominated by the diffusive mass transport, a decrease in the net solute concentration is found as compared to the non-reactive case. This decrease is pronounced at higher values of the Damköhler number when the solute reaction rate becomes larger than the solute diffusion rate. Furthermore, the flow structure is affected by products generated by the chemical reaction when the Rayleigh number for the products is sufficiently high. In that case, numerical simulations show the formation of diluted fluid tongues exhibiting damped periodic oscillations about a nonzero mean. The results are obtained using the pseudospectral numerical method, verified against the analytical solution for the non-reactive, purely diffusive case. [ABSTRACT FROM AUTHOR]