bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatigue Life Analysis and Equal Life Optimization Design of Fluid End of Septuple Fracturing Pump
Authors: Wang Bo , Zhou Huan-hui , Zhao Chong-sheng , Huang Kun-peng , Cheng Ming-hao , Wu Qiang , Deng Jie , Xu Ji-duo 
Published: November 2024

Abstract
To determine the cause of failures phenomenon of fatigue cracks in the crossbore area of septuple fracturing pump 4 inch fluid end, optimal design the fluid end based on the idea of equal fatigue life to reduce non-uniformity and prolong fatigue life. Firstly, the static finite element analysis under 14 design conditions and 1 test condition are calculated, the results fulfill the static strength requirements. Next, based on the static of 14 actual working conditions, find cycle peaks through constant amplitude alternating load, the fatigue life and distribution rule were calculated. Then, increase the single side width increment e to 75mm, non-uniformity between 7 cylinders is reduced from 26.6% to 1.35%, the fatigue life is prolonged by 98.2%. Finally, by parameter optimization of the crossbore fillet radius Ru to 15mm and reducing the distance from the central axis of the suction cylinder to the top 25mm, the non-uniformity of the cylinder 4 is reduced from 20.07% to 7.67%, the fatigue life is prolonged by 40.9%, and it is prolonged by 179.4% totally. The results show that the analysis method by finding cycle peaks can accurately calculate the fluid end fatigue life. The equal fatigue life parameter optimization approach has obvious consult significance for reduce non-uniformity and prolong fatigue life of septuple fluid end.
Study on Production in Different Layers of Tight Reservoir
Authors: Zhao Shuangshuang 
Published: November 2024

Abstract
In rencent years, the tight oil blocks in our factory are all developed without injectio n and put into production by large-scale fracture network. There are problems of low initial pro duction and fast decline, and the development effect is poor. Because of the large inclination A ngle of the vertical well, it is impossible to obtain the test results of stratified fluid production b y conventional test methods. At the same time, the understanding of tight oil reservoir utilizatio n status after large-scale reconstruction is not clear enough. Therefore, the test of liquid product ion profile in inclined vertical Wells is explored. Meanwhile, the results of conventional liqui d production profile are applied to in-depth analysis of reservoir utilization status in convention al blocks and test blocks respectively, and the relationship between different reservoir types an d fracturing scale and liquid production capacity is determined. The influencing factors and app lication principles of CDFT test results were clarified, the understanding of different reservoi r utilization conditions was obtained, and the main direction of the optimal design of fracturin g program was clarified, which provided technical support for the subsequent design and optim ization of fracturing program in the new district.
Interwell channeling and sealing technology in Changqing CCUS block
Authors: Gao Guocheng , Yang Jinfeng , Wang Wenbin , Deng Kai , Xin Meng 
Published: November 2024

Abstract
In the Changqing Oilfield’s CCUS (Carbon Capture, Utilization, and Storage) project, a novel fracture-based inter-well gas migration sealing technology was developed to address the challenges of reduced production and even shutdown of oil and water wells due to inter-well migration. This was particularly crucial in the context of low fracture pressure-bearing capacity below 40 MPa, the absence of precedents in inter-well gas migration sealing techniques, and the difficulty in accurately estimating the fracture communication volume. The technology is grounded in multi-segment plug water blocking techniques, utilizing geological and well-network data to simulate the gas volume within fractures, thereby determining the precise quantity of plugging agent required. To meet the long-term sealing needs, the technology not only incorporates corrosion-resistant gel in the multi-segment plugs but also integrates water-dispersive cement slurry and CO2 corrosion-resistant cement slurry to enhance the durability of the seal. The injection parameters were optimized based on the pressure-bearing characteristics of the formation to prevent pressure leakage. Field tests indicated that the injection pressure increased by 4 MPa after the application of this technology. Despite the occurrence of gas migration during the plugging process, the close approximation between the designed injection volume of 350 cubic meters and the actual required volume of 326 cubic meters suggests that the technique could achieve its intended effectiveness with further adjustments. This technology provides new insights for handling similar inter-well migration issues in CCUS projects and serves as a reference for other similar endeavors.
Effect of Hydrate Saturation on Triaxial Shear Mechanical Properties of Methane Hydrate-Bearing Sediment
Authors: Sun Yuqi , Liu Li , Hui Chengyu , Zhang Yiqun , Ji Guodong 
Published: November 2024

Abstract
As a clean energy source, natural gas hydrate resources are essential to the development of energy in the twenty-first century. However, the degree of consolidation of the hydrate reservoir is low, and complex accidents such as wellbore instability, reservoir collapse, and gas production leakage will be caused if improperly exploited. The laboratory employs a self-developed triaxial shear test equipment that operates under high pressure and low temperature conditions. This equipment is specifically designed to determine the mechanical parameters and strength characteristics of methane hydrate bearing sediment (MHBS) samples. It is used to create water-saturated hydrate deposits with varying levels of saturation. The synthesis of MHBS samples with varying saturations is achieved by precisely regulating the amount of water. The saturation of MHBS is then determined and confirmed by the utilization of the “water content method” and the “gas collection method.” Triaxial shear tests are conducted on MHBS to examine the impact of hydrate saturation on the mechanical parameters and strength behaviours of MHBS. The experimental findings demonstrate that the presence of hydrate crystals enhances the robustness of the depositing medium. The stress-strain curves of MHBS have a hyperbolic shape, indicating strain hardening features. The stress-strain curves may be categorized into three distinct stages: the initial elastic deformation, followed by a slow shift to the initial yield deformation, and ultimately leading to strain hardening. As axial strain rises, the behaviour of the MHBS transitions progressively from elastic deformation to plastic deformation. The shear strength and initial yield strength of MHBS enhance with higher hydrate saturation. The reason for this is that as the hydrate saturation rises, the influence of hydrate crystals on the enhancement of sediment strength becomes more pronounced. However, the initial yield strain of each MHBS sample is between 0.5% and 1.5%, and the difference is not significant. When the hydrate saturation rises gradually, the cohesion of MHBS enhances. Nevertheless, the hydrate saturation has a very minor impact on the internal friction angle.
Controlling Factors of Dissolution Pores in Zeolite Cements of Permian Clastic Rocks in Northwest of Junggar Basin
Authors: Guo Mozhen , Ni Xinfeng 
Published: November 2024

Abstract
Zeolite cement dissolution pores, buried at a depth of over 3600 meters, are found well developed in clastic rocks of Permian in northwest of Junggar basin. Studying the controlling factors of zeolite cement dissolution pores have important meaning to predict the distribution of favorable reservoirs in deep oil and gas exploration of Permian. A comprehensive research method of thin slice analysis of 800 pieces of castings from 60 wells, core observation, scanning electron microscopy, and clay mineral analysis was adopted. It is believed that the dissolution pores of zeolite cements are mainly controlled by zeolite distribution, the scale and range of inorganic and organic acids. Firstly, different zeolite cement types appear a regular pattern that control dissolution pore types and their distribution scope. The study area are well developed three types zeolite cements: heulandite, analcite and laumontite. The heulandite cements are developed in basin edge, showing a belt-like distribution, and then the analcite distribution area. laumontite cements are distributed in basin central. Horizontally in basin edge, reservoir pore type is primary intergranular pore, and followed by analcite dissolution pore. In central basin, the major pore type is laumonitite dissolution pore, and followed by primary intergranular pore. No heulandite dissolution pores are found in study area. Secondly, analcite dissolution pores, formed by inorganic acid and distributed in basin edge, are controlled by the scale of stratigraphic unconformities and faults. Laumonitite dissolution pores, formed by organic acid and developed in central basin, are controlled by the scope of source rock. Thirdly, it is proposed that the meddle-belt of basin is the favorable zone for Permian reservoirs because it is located fan delta front where the laumontite cement is developed, close to the source rock, and in the updip direction of the three stages of organic acid migration. It is considered that central basin has favorable conditions to form laumontite dissolution pores, and pointed out that this zone is a favorable zone for the development of deep reservoirs in the Permian.
Enhanced Oil Recovery Technology in High-Temperature Shale Oil Reservoirs: A Review
Authors: Li Qi , Wang Xiaoyan , Ge Hongjiang , Li Dongping , Zhang Yang , Yang Weihua 
Published: November 2024

Abstract
As a strategic continuation resource, shale oil has abundant reserves and significant development potential, with the decrease of conventional oil and gas resources. However, in contrast to North American marine shale oil, China’s shale oil is mostly continental, has high reservoir heterogeneity, ultra-low permeability and porosity, and the oil recovery is generally lower than 10%. In this review, the advances in laboratory research and field application of enhanced oil recovery (EOR) technologies such as gas injection, agent injection and nanomaterial injection in high-temperature shale reservoirs are systematically reviewed, and the mechanisms of various technologies are also explained, as well as their advantages and disadvantages. In particular, the problems and challenges faced by EOR are thoroughly analyzed, and suggestions and strategies for the efficient development of shale oil are proposed. Gas injection is an effective method to supplement formation energy in shale reservoirs, which can effectively enhance shale oil production, but there are problems with gas sources, gas channeling and corrosion. At present, injection agents and nanomaterials are still in the laboratory research stage and have not formed large-scale applications in shale reservoirs. In the future, it will be important to thoroughly research the interface impact of various injection medium and oil-water-shale, clarify the applicability of shale oil EOR technologies, accelerate the key test of shale oil stimulation technology, and help scale benefit development and high-quality development of shale oil.
Drilling Technology of Large Plumb Ratio Shallow Shale Gas Well
Authors: Wang Bo , Zang Xiangmei , Wang Xuanchao 
Published: November 2024

Abstract
SY1H is the first shallow shale horizontal well deployed in Jilin Oilfield, with a depth of 1,150m in Qing1 section of the target layer, a designed horizontal section length of 2,000m, and a water-drag ratio of nearly 2:1, so the well is characterised by the difficulty of pressurising with a large digit-drag ratio, the high friction between the drilling and the lower casing, and the shale wall being easy to be destabilised and collapsed. There are no horizontal wells in the neighbouring wells with a section of green as the destination layer, and there is a lack of reference materials, and the stability of the shallow shale is not clear. In order to ensure that the well can be reached and drilled for a long time, a technical route was formulated with the objectives of effectively reducing drilling resistance, increasing drilling pressure, and rapid drilling and completion within the collapse cycle, and technical measures such as equipping with a top drive and a high-grade drilling rig to increase the drilling pressure, oil-based drilling fluids and rotary guiding to reduce drilling resistance and the ability to deal with complex situations, and floating casing process to ensure that casing can be smoothly lowered in place, etc., so as to achieve safe and rapid construction of SY1H and achieve a horizontal section of 2,000m. construction and achieve the geological target of 2000m horizontal section.
Research and Application of Smart Temporary Plugging Gel for Small Casing Cementing in Changqing Oilfield
Authors: Zhang Yan , Wan Xiangchen , Min Jiangben , Li Siyang , Li Peng , Li Yancheng 
Published: November 2024

Abstract
In response to the serious leakage and low productivity recovery rate after cement plugging during the secondary cementing process of repairing small casing in the old wells of Changqing Oilfield, this study draws on the theory of shielding and temporary plugging in the drilling process to propose an adaptive smart temporary plugging gel technology. This technology has developed a weak gel suspension base liquid and synthesized a polymer material with good viscosity, high deformability, high sealing strength, and the ability to automatically hydrate and degrade at a certain temperature. It synergistically cooperates with other auxiliary temporary plugging materials to form an adaptive and self-degrading temporary plugging gel system, which can quickly form a sealing barrier at severely leaking areas such as corroded perforations, effectively preventing cement slurry leakage during subsequent cementing processes, shortening the operation cycle, and protecting the reservoir. Experimental evaluations indicate that the gel system can withstand pressure up to 15MPa, degrades in 7-10 days, and achieves a reservoir recovery rate of over 90%, effectively achieving the goals of plugging, releasing, and minimizing reservoir pollution. It has been applied in 30 wells in the Changqing Oilfield, with a success rate of over 96% in the first plugging operation, and an average production recovery rate of over 95%, significantly protecting the oil reservoir.
Study on the Percolation Law of Tight Gas in the Western Sulige Area based on the Lattice Boltzmann method
Authors: Xie Yang , Wang Chunpu , Gao Xiaomian 
Published: November 2024

Abstract
To address the problem of unable to determine the percolation law of tight sandstone gas reservoirs under laboratory conditions, especially when there are no water production measurements and no obvious edge and bottom water. In this study, takes the Western Sulige area as the research object, and based on the geological characteristics of the Western Sulige area and the lattice Boltzmann method, establishes a LB mechanism model for tight gsa in the Western Sulige area, identify Identify fluid distribution and percolation rules in the pore throat structure of Western Sulige area The results show that There are four types of bound water in the pore throats of the western Sulige area, including trapped water, bind pore water, dead pore water, and liquid film.. The remaining gas in the production process is mainly distributed in the pore throat structure, including bind pore gas, fine throat pore gas, and water seal gas. In the early stage of gas-water production, formation water mainly in the form of liquid film reduces the cross-section of natural gas flow. Subsequently, formation water mainly in the form of liquid droplets clogs the throat, thereby reducing the gas percolation capacity. Due to the capillary suction effect, liquid–solid viscous forces, and pore–throat structures, the reservoirs of Western Sulige Area is prone to water lock damage, resulting in reduced production and even production suspension of gas wells. Therefore hydraulic fracturing is a necessary measure for the development of tight gas, but the increase in the intensity of fracturing operations has increased the width of fractures and strengthened the water lock phenomenon, further worsening the percolation capacity of the matrix.
Formation pressure prediction method based on machine learning
Authors: Zhang Zhen , Yan Chuanliang , Cheng Yuanfang , Han Zhongying , Wu Sini 
Published: November 2024

Abstract
Formation pore pressure is one of the key parameters in petroleum engineering. The high-temperature and high-pressure working conditions formed under the complex mechanism of Yingqiong Basin make downhole complex events such as overflow and well leakage occur frequently. To address the problem of the large prediction error of the traditional Eaton method under high temperature and high-pressure conditions, three machine learning methods, such as GA-BP(Genetic Algorithm-Back Propagation Neural Network), PSO-LSTM(Particle Swarm Optimization-Long Short-Term Memory Neural Network), SVR(Support Vector Regression), are introduced to find the nonlinear relationship between logging parameters and formation pore pressure. Seven logging parameters such as formation depth, mechanical drilling speed, drilling pressure, and rotational speed were used as input variables, and formation pore pressure was used as an output variable through correlation analysis for constructing the machine learning model. By analyzing the experimental results of the above three machine learning models with the Eaton method, the GA-BP model with lower error and more satisfying the needs of drilling engineering is preferred, and the various regression evaluation indexes of the model are also more excellent compared with other machine learning models, which are Mean Squared Error (MSE)=0.001, Mean Absolute Error (MAE)=0.003, and R-squared (R2)=0.991, respectively. It is concluded that the machine learning method is not only more advantageous in a class of nonlinear regression problems such as formation pore pressure prediction, but also can help engineers to predict formation pore pressure more accurately under the conditions of deep high-temperature, high-pressure, and complex formations, which contributes to guaranteeing the safety and high efficiency of drilling projects.
Quantitative Evaluation of “Four Qualities” in Deep CBM Using Logging Data
Authors: Yan Ping , Li Zhongbai , Yu Hongguo , Hu Gang , Feng Lixiang , Chen Jiayu , Gao Yanning , Du Xin , Wang Wei , Wang Deqiang 
Published: November 2024

Abstract
The four qualities of deep CBM (CBM resources buried depth greater than 2000 m), including coal rock quality, reservoir quality, well completion quality, and coal seam roof and floor quality, are important factors that determine the degree of coal rock gas enrichment, preservation conditions, and effective mining. Taking the deep CBM in the Ordos Basin as the research object, based on coal core experiments, sensitive logging information research on the “four qualities” key parameters of coal rock reservoirs is carried out, and a quantitative logging evaluation method for key reservoir parameters is established to provide support for the comprehensive evaluation of deep CBM. Coal rock quality parameters include macroscopic coal rock type, coal industrial components, coal macerals, coal structure, etc. The key parameters of reservoir quality include coal rock porosity, permeability, and gas content. The key parameters of well completion quality include rock mechanics parameters, stress and fracture pressure. The parameters of coal seam roof and floor quality include comprehensive evaluation of the lithology, stability, and sealing ability. By delving into the “four qualities” of deep CBM in logging data, combined with drilling, mud logging, coal core analysis and laboratory data, and using corresponding quantitative evaluation methods for logging, we aim to provide logging technical support for the optimization of favorable target areas for deep CBM exploration, single well fracturing layer selection, and reserve calculation.
Calculation of the Critical Liquid Production of Cyclic Steam Stimulation in Heavy Oil Reservoir with Edge Water
Authors: Zheng Wenqian , Liu Dong , Liu Xiaohong , Geng Zhigang , Miao Feifei 
Published: November 2024

Abstract
For heavy oil reservoirs with edge water, when the liquid production of cyclic steam stimulation is excessively high, there is a risk of edge-water invasion. Therefore, the liquid production of cyclic steam stimulation is of great significance to the prevention of edge-water invasion in heavy oil reservoir with edge water. Currently, many studies on the critical liquid production in oil reservoir by water flooding are conducted. However, there is few research on the critical liquid production in heavy oil reservoir by cyclic steam stimulation. To fill this gap, The formation after cyclic steam stimulation is divided into the heated zone and the unheated zone. A characterization method for the flow field parameters after cyclic steam stimulation is established. By transforming the length of the thermal swept zone, the comprehensive mobility of the heated zone is equivalently represented as the comprehensive mobility of the unheated zone. On this basis, considering the threshold pressure gradient in heavy oil, a calculation method for the critical liquid production after cyclic steam stimulation in oil reservoir is developed based on the theory of mirror reflection and the superposition of potentials. The results show: (1) Permeability being constant, the critical liquid production rate increases with the increase in cyclic steam injection quality. With a constant cyclic steam injection quality, the critical liquid production rate increases with the increase in permeability; (2) Guided by the established relationship curve diagram between critical liquid production and crude oil mobility, the development plan is designed. As a result, the comprehensive water cut in the oilfield is 8.1%, and no water invasion has occurred; (3) Guided by the established relationship curve diagram between the cumulative liquid production and cumulative heat injection corresponding to different critical liquid production rates, adjustments were made to the oilfield development plan. As a result, the critical liquid production rate for well A1 increased from 110 t/d in the first cycle to 150 t/d in the second cycle.