SPE Journal最新文献

{"title":"Simulation of Hydrate Particles Aggregation and Deposition in Gas-Dominated Flow","authors":"Zhiyuan Wang, Zeqin Li, Jihao Pei, Nan Ma, Jianbo Zhang, Baojiang Sun","doi":"10.2118/218384-pa","DOIUrl":"https://doi.org/10.2118/218384-pa","url":null,"abstract":"Owing to low-temperature and high-pressure production environments, hydrate generation, accumulation, and deposition are prone to occur in deepwater oil and gas production wells and transportation pipelines, leading to pipeline blockage and threatening the safety of oil and gas production. To explore the aggregation mechanism and deposition law of hydrate particles in the main gas diversion pipeline, this study considered the adhesion effect of hydrate particles and established a hydrate particle aggregation and deposition model based on theory and experiments. The coupled computational fluid dynamics-discrete element method (CFD-DEM) is used in the simulation calculation. The simulation results were compared with the relevant experimental results, and maximum and average errors of 9.48% and 4.56% were observed, respectively. It was found that the main factor affecting the aggregation of hydrates is the adhesion between particles. As the subcooling temperature increased, the aggregation and adhesion of the hydrate particles increased to varying degrees. The tangential adhesion force between the hydrate aggregate particles was significantly greater than the normal adhesion force, and the adhesion force between the particles gradually increased from the surface to the interior of the aggregates. The coordination number of the hydrate particles can quantitatively characterize the degree of aggregation and is affected by many factors, such as adhesion. By studying the particle coordination number, the evolution of hydrate accumulation and deposition under different conditions can be summarized. Based on the simulation results, the mathematical relationship between different dimensionless numbers and hydrate deposition ratio (HDR) was calculated, and an expression that can predict the HDR was obtained, with an average relative error of 10.155%. This study provides a theoretical basis for predicting the aggregation and deposition of hydrate particles in gas-dominated systems and a reference for the development of hydrate prevention and control plans.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"15 2 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139298913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reservoir Drilling and Openhole Gravel Packing with High-Density Cesium Formate Fluids in a High-Pressure, Marginal Mud Window Environment at Martin Linge","authors":"Simen Jøsang Nilsen, Hanne Undheim Obrestad, H. Kaarigstad, Nadia Mansurova, Tom Are Solvoll, Johan Løchen, Siv Howard, Ben Abrahams, Christian Busengdal","doi":"10.2118/212487-pa","DOIUrl":"https://doi.org/10.2118/212487-pa","url":null,"abstract":"High-density cesium/potassium (Cs/K) formate fluids were successfully utilized from reservoir drilling to upper completion installation in five productive Martin Linge high-rate gas wells. Four wells were completed with openhole gravel pack (OHGP) and one with standalone sand screens. The gravel packing operation marks what is considered to be the highest density carrier fluid OHGP successfully completed worldwide, with a specific gravity (SG) of 2.06. A complex operation under pressure and temperature conditions (745–780 bar and 135–140°C) that almost qualify as high pressure/high temperature (HP/HT), including managed pressure drilling (MPD), overbalanced screen running, and openhole gravel packing, was simplified by using the same base brine throughout the operation. Cs/K formate reservoir drilling fluid (RDF) and screen-running fluid were designed with biopolymeric additives and minimal calcium carbonate bridging particles. Clear Cs/K formate brine was chosen as gravel pack (GP) carrier fluid. The use of Cs/K formate fluids for all stages of the operation reduced the complexity of transitioning between the operational stages. In addition, the reservoir was only exposed to one filtrate without application of damaging weighting solids. The drilling fluid contributed to successful MPD and delivered wells with very good hole quality in the reservoir, which consisted of interbedded sandstone, coal stringers, and shale. The shale-stabilizing properties of concentrated formate brine–based fluids provided acceptable conditions for extended openhole time and allowed additional logging runs, including pore pressure measurements, under near-HP/HT conditions, before running the screens. One bottom-up cleanout was conducted before the screen-running fluid was circulated in and the screens installed. The spurt and seepage losses were low throughout the drilling and screen-running phases. No breaker treatment was required in any of the wells. All wells have proved to have good initial productivity and high well productivity index. The successful OHGP operations performed with the high fluid densities required in Equinor’s Martin Linge field have set a new standard for well completions in challenging high-pressure environments.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"1 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139301347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Real-Time Gamma Ray Log Generation from Drilling Parameters of Offset Wells Using Physics-Informed Machine Learning","authors":"Prasham Sheth, Sailaja Sistla, Indranil Roychoudhury, Mengdi Gao, Crispin Chatar, Jose Celaya, Priya Mishra","doi":"10.2118/212445-pa","DOIUrl":"https://doi.org/10.2118/212445-pa","url":null,"abstract":"By 2026, USD 5.05 billion will be spent per year on logging while drilling (LWD) according to the market report from Fortune Business Insights (2020). Logging tools and wireline tools are costly services for operators to pay for, and the companies providing the services also have a high cost of service delivery. They are, however, an essential service for drilling wells efficiently. The ability to computationally generate logs in real time using known relationships between the rock formations and drilling parameters, namely, rate of penetration (ROP), rotations per minute (RPM), surface weight on bit (SWOB), surface torque (TQX), standpipe pressure (SPPA), and hookload (HKLD), provides an alternative method to generate formation evaluation information (analysis of the subsurface formation characteristics such as lithology, porosity, permeability, and saturation). This paper describes an approach to creating a digital formation evaluation log generator using a novel physics-informed machine learning (PIML) approach that combines physics-based approaches with machine learning (ML) algorithms. The designed approach consists of blocks that calculate mechanical specific energy (MSE), physical estimates of gamma ray (GR) using physical and empirical models, and formation information. All this information and the drilling parameters are used to build a classification model to predict the formations, followed by formation-based regression models to get the final estimate of GR log. The designed PIML approach learns the relationships between drilling parameters and the GR logs using the data from the offset wells. The decomposition of the model into multiple stages enables the model to learn the relationship between drilling parameters data and formation evaluation data. It makes it easier for the model to generate GR measurements consistent with the rock formations of the subject well being drilled. Because the computationally generated GR by the model is not just dependent on the relationships between drilling parameters and GR logs, this model is also generalizable and capable of being deployed into the application with only retraining on the offset wells and no change in the model structure or complexity. For this paper, the drilling of the horizontal section will not be discussed, as this was done as a separate body of work. Historically collected data from the US Land Permian Basin wells are used as the primary data set for this work. Results from the experiments based on the data collected from five different wells have been presented. Leave-one-out validation for each of the wells was performed. In the leave-one-out validation process, four of the wells represent the set of offset wells and the remaining one becomes the subject well. The same process is repeated for each of the wells as they are in turn defined as a subject well. Results show that the framework can infer and generate logs such as GR logs in real time. The average root-mean-squar","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"113 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139305994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Molecular Structure of Thio-Chemicals on Corrosion Inhibition in CO2 Corrosive Environments","authors":"Jiang Yang, Xintong Wang, Yefei Wang, Zhen Yang","doi":"10.2118/213848-pa","DOIUrl":"https://doi.org/10.2118/213848-pa","url":null,"abstract":"Carbon dioxide (CO2) is frequently present in oil and gas fields, and its use in CO2 flooding for enhanced oil recovery is growing. However, CO2 is highly corrosive to steel in oilfield fluid. The effective and economical method for controlling corrosion is the addition of corrosion inhibitors for carbon steel materials. Thio-compounds of small size have shown potential as corrosion inhibitors to enhance the performance of imidazoline inhibitors. In this study, several small thio-derivatives inhibitors including mercaptoethanol (ME), thiourea (TU), mercaptoacetic acid (TGA), and 2-mercaptobenzimidazole (MBI) were compared to inhibit the CO2 corrosion. They were used as synergists to enhance corrosion inhibition of oleic imidazoline (OIM) on carbon steel in CO2-saturated brine at 60°C. The corrosion inhibition was evaluated using weight loss and electrochemical techniques, while the surface was characterized using atomic force microscopy (AFM). Additionally, quantum chemical calculations were conducted to investigate the mechanism of corrosion inhibition. The results demonstrate that the MBI, with its aromatic group, exhibited superior corrosion inhibition performance compared with ME, TGA, and TU. The surface characterization revealed no pitting and localized corrosion at 10 ppm of inhibitor. A proposed interaction model suggests that OIM becomes protonated and forms a coadsorption layer with MBI on the carbon steel surface through electrostatic attraction. MBI adsorbs onto iron through a bidentate binding-N-S-bridge connection, effectively preventing carbon steel corrosion in the CO2 environments. This research contributes to establishing a structure-properties relationship for thio-chemicals, aiding in the development of more efficient corrosion inhibitors.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"8 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139301366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrosion Inhibition of Benzyl Quinoline Chloride Derivative-Based Formulation for Acidizing Process","authors":"Zhen Yang, Yefei Wang, Jiang Yang, Jing Wang, M. Finšgar","doi":"10.2118/218374-pa","DOIUrl":"https://doi.org/10.2118/218374-pa","url":null,"abstract":"Due to the severe and rapid corrosion of metallic equipment by strong acids at high temperatures, a high concentration of acidizing corrosion inhibitors (ACIs) is required during acidizing processes. There is always a need to develop more effective and environmentally friendly ACIs than current products. In this work, a highly effective ACI obtained from a novel main component and its synergistic effect with paraformaldehyde (PFA) and potassium iodide (KI) is presented. The ACI was prepared from the crude product of benzyl quinolinium chloride derivative (BQD) synthesized from benzyl chloride and quinoline in a simple way. The new ACI formulation, named “synergistic indolizine derivative mixture” (SIDM), which consists of BQD, PFA, and KI, showed superior corrosion inhibition effectiveness (IE) and temperature stability compared with commercially available ACI. More importantly, the SIDM formulation eliminates the need for commonly used highly toxic synergists (e.g., propargyl alcohol and As2O3). In a 20 wt% hydrochloric acid (HCl) solution, the addition of 0.5 wt% SIDM mitigates the corrosion rate of N80 steel down to less than 0.00564 lbm·ft−2 at 194°F, while the corrosion rate at 320 °F is 0.0546 lbm·ft−2·when 4.0 wt% SIDM is added.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"8 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139301418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and Simulation Investigation on Ball-Sealer Transport and Diversion Performance Aided by Machine Learning Method","authors":"Hai Qu, Ying Liu, Chengying Li, Zhijun Zeng, Xu Liu, Zhelun Li","doi":"10.2118/218010-pa","DOIUrl":"https://doi.org/10.2118/218010-pa","url":null,"abstract":"Summary Ball-sealer diversion has been proven to be an effective and economical way to increase fractures and fracturing volume in multistage hydraulic fracturing and matrix acidizing treatments. However, designing and implementing a successful ball-sealer diversion treatment is still challenging. Typically, operators rely on empirical data to determine diversion parameters and need an understanding of accurate ball transport and diversion behaviors. A model for optimizing operating parameters, including fluid and ball properties, and predicting the diversion performance of ball sealers before treatment is needed for designing the fracturing process. In this work, we systematically investigated ball-sealer diversion using experimental and numerical methods. The resolved model of computational fluid dynamics (CFD) and discrete element method (DEM) is first developed to simulate the transport of a large ball in a horizontal wellbore with side holes. The experimental results validated the numerical model. The effects of the ball position in the pipe, flow ratio of the hole to pipe, injection flow rate, and ball density on the diversion performance were studied under field parameters. The results show that the ball sealer easily misses the heel-side perforation due to the inertial effect and travels to the toe side due to the large inertia and turbulent flow. The ball position and flow rate ratio are crucial for the diversion performance. There is a threshold value of the ball position under the specific condition, and the ball successfully turns to the perforation only when the threshold distance is met. A ball sealer closer to the perforation will have a larger probability of blocking the hole than the ball at the other side of the wellbore. The larger the flow rate ratio, the more the drag force on the ball, and the ball can successfully divert to the perforation despite the ball being far from the hole. The injection flow rate and ball density negatively correlate with the diversion performance due to the large inertia and gravity. The best classification result with the F1 score of 87.0% in the prediction set was achieved using the random forest (RF) algorithm. It provides new insight into developing ball sealers and adjusting fracturing parameters based on machine learning (ML) methods.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"8 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135371877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication and Release Mechanism Study of a Nanocapsule Breaker for Controlling Degradation Rate of Insoluble Residue in Slickwater at Moderate-Temperature Reservoirs","authors":"Jingyang Pu, Ming-liang Luo, Kai Wang, Xu Li, Jin-bo Wu, Na Zhang, Yang Zhao, Mingjing Lu","doi":"10.2118/217981-pa","DOIUrl":"https://doi.org/10.2118/217981-pa","url":null,"abstract":"Summary In an ideal hydraulic fracturing project, the viscosity of hydraulic fracturing fluid (HFF) should drop to facilitate an efficient and quick fracture cleanup once proppants have been placed. Ammonium persulfate (APS) is widely used as an oxidizer breaker to degrade the insoluble residue of the HFF. However, a complex network of artificial fractures with sizes ranging from millimeters to micrometers restricts the transportation application and reaction time of standard breakers and current millimeter-sized capsule breakers. In this study, we introduce an APS nanocapsule (APS-NC) breaker, fabricated via a simple miniemulsion technique, that is capable of addressing the degradation of insoluble residue of the HFF in deep fractures. The nanocapsules are produced through precise control of the nanoprecipitation of poly(methyl methacrylate) (PMMA) onto aqueous APS nanodroplets. Stable aqueous nanodroplets are generated by means of an inverse miniemulsion using Pluronic P-123 as a specific surfactant to form a large and stable water-oil internal surface referring to the long chain and amphipathic property of Pluronic P-123 molecule. Pluronic P-123 is included in the process not only to stabilize the miniemulsion and increase the precipitation efficiency of PMMA but also to function as a thermo-responsive switch for the delayed burst release of APS. The size of the resulting nanocapsules can be controlled within the 207 and 821 nm range, yielding APS up to 92%. The release rate of APS can be controlled by the initial amount of PMMA (150–300 mg), environmental temperature (40–80°C), and environmental pH (3.4–7). When the temperature was 80℃, the initial amount of Pluronic P-123 dominated the release dynamic of APS. Compared with the APS breaker in a dynamic degradation experiment, the APS-NC had a more controllable degradation profile that could cause hydrolyzed polyacrylamide (HPAM) to burst degrade after 6 hours of heating at 80°C.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134937296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Optimization of a High-Frequency Axial-Torsional Composite Percussion Drilling Tool for Enhanced Impact Technology","authors":"Haili Yang, Yinglin Yang, YueXiang Huang, Hengjing Zhang, Liangliang Xie","doi":"10.2118/218006-pa","DOIUrl":"https://doi.org/10.2118/218006-pa","url":null,"abstract":"Summary A high-frequency axial-torsional composite percussion drilling tool is designed to enhance the drilling efficiency by delivering high-frequency axial and torsional impact loads directly to the drill bit. The impact performance and influencing factors of the tool are analyzed via the large eddy simulation method, and a scaled-down experiment on the pulse nozzle structure is conducted. The analysis reveals that after design optimization, the tool achieves high-frequency axial and torsional impacts of 421 and 284 Hz, respectively, at an inlet flow rate of 30 kg/s. Additionally, the unilateral amplitudes of the axial and torsional impact loads reach 1511 N and 19.3 N·m, respectively, with a pressure drop of 2.998 MPa. Furthermore, the similarity degree between the parameters derived from the experiment and numerical analysis is close to or exceeds 70%, demonstrating the reliability and precision of the numerical analysis results. Overall, this study sets a baseline for high-frequency impact technology, paving the way for further advancements in drilling efficiency.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136153898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solution Gas/Oil Ratio Prediction from Pressure/Volume/Temperature Data Using Machine Learning Algorithms","authors":"Asia Majid, Grant Charles Mwakipunda, Chaohua Guo","doi":"10.2118/217979-pa","DOIUrl":"https://doi.org/10.2118/217979-pa","url":null,"abstract":"Summary Many methods have been developed to determine the solution gas/oil ratio (Rs), starting with experiments, followed by empirical correlations establishments, and recently with machine learning applications receiving much interest due to their ability to produce precise results compared with empirical correlations. In this paper, the group method of data handling (GMDH) and the enhanced GMDH based on discrete differential evolution (GMDH-DDE) are used for the first time to estimate the Rs and to provide a correlation to the laboratory measured Rs from bubblepoint pressure (Pb), oil API gravity (API), gas-specific gravity (γg), and reservoir temperature (T) without crude oil properties. These two methods are compared with backpropagation neural networks (BPNN). The reason for using the hybrid GMDH (GMDH-DDE) is to overcome the drawbacks of the GMDH, such as the method used to calculate neuron weights (i.e., quadratic polynomial transfer function), which seems to have inaccuracies. Also, in selecting model inputs, the GMDH tends to choose the most appropriate inputs for the model; however, the selection criteria are not straightforward and may affect the final results. Furthermore, the GMDH has a multicollinearity problem, affecting model coefficient stability and overfitting problems, etc. A total of 420 data sets from the Mpyo oil field were used, with 70% used for training and 30% used for testing. According to the findings, the GMDH-DDE outperformed both the GMDH and BPNN. In comparison with the GMDH and BPNN, the GMDH-DDE has a higher correlation coefficient (R), lower root-mean-square error (RMSE), and lower mean absolute error (MAE). During training, R, RMSE, and MAE were 0.9849, 0.090, and 0.010, respectively, and during testing, R = 0.9603, RMSE = 0.290, and MAE = 0.017. The second-best technique (GMDH) produces R, RMSE, and MAE values of 0.9611, 0.122, and 0.032 in training, and R = 0.9438, RMSE = 0.349, and MAE = 0.055 in testing. Furthermore, the GMDH-DDE used less computational time (1.32 seconds) compared with the GMDH (2.01 seconds) and BPNN (4.96 seconds), proving that the GMDH-DDE has accurate and fast convergence compared with the GMDH and BPNN. These findings show that the GMDH-DDE and GMDH can be adopted as alternative methods for predicting the Rs.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135762424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Polishing on Cutting Efficiency and Mechanical Properties of PDC Cutters","authors":"Jiusen Wei, Wei Liu, Deli Gao, Dameng Guo","doi":"10.2118/217997-pa","DOIUrl":"https://doi.org/10.2118/217997-pa","url":null,"abstract":"Summary Polycrystalline diamond compact (PDC) bits equipped with polished cutters have shown improvements in drilling performance compared to the bits using nonpolished cutters. Despite the positive feedback from numerous global field runs, the merits of polished cutters are still not fully studied and not taken seriously, for example, by the bit manufacturers and drilling engineers in China. In this work, the effect of polishing on the rock-cutting efficiency and mechanical properties of PDC cutters was comprehensively analyzed through laboratory tests and field trials. The underlying mechanism was also investigated through theoretical modeling and experimental results. A rock-cutting force model of a single PDC cutter was developed to elucidate the effect of polishing on the rock-cutter interaction considering the friction between the cutter surface and rock cuttings. The results revealed that the polished cutter has better rock-cutting efficiency because the polishing reduces the friction on the cutter surface. This reduction in friction facilitates the evacuation of rock cuttings from the crushing zone and plastic flow zone, leading to lower mechanical specific energy (MSE) compared to the nonpolished diamond surface. Moreover, the polished cutters exhibit improved thermal stability and better impact fatigue resistance while maintaining comparable wear and impact resistance to nonpolished cutters. To further validate the findings, two field trials were conducted in Sinopec Shengli Oilfield. The first field trial using four PDC bits with polished cutters and one bit with nonpolished cutters found that the bits with polished cutters obtained a higher rate of penetration (ROP) in drilling hard and plastic mudstone, which agreed well with the theoretical and experimental results. In the second field trial, it was noted that the polished cutters presented comparable mechanical properties to nonpolished cutters, which was also consistent with experimental results. However, the advantages of polished cutters in thermal stability and impact fatigue resistance were not distinguished in the field trials. This work elucidated the beneficial effect of polishing in enhancing the drilling efficiency of PDC cutters and, more meaningfully, without sacrificing the mechanical properties of PDC cutters, which provided solid evidence to convince bit manufacturers and drilling engineers for the broader adoption of polished cutters.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135810748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}