bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on Mechanism and Effect of Different Viscosity Reducing Methods on Offshore Heavy Oil
Authors: Liao Hui , Liu Zongbin , Liu Dong , Ge Taotao , Du Chunxiao 
Published: November 2024

Abstract
Bohai is rich in heavy oil. And its efficient development is significant. In this essay, ordinary heavy oil and extra one were selected, and the viscosity characteristics was also investigated referring to its internal composition. And so as the reducing viscosity effects of steam, oil-soluble viscosity reducer, diesel, emulsifier, flue gas and carbon dioxide. The experimental results show that resin and asphaltene content have positive effect on the viscosity of heavy oil. Compared with ordinary heavy oil, the drop is significantly greater when the temperature increases by 10°C. For ordinary heavy oil, the inflection point temperature is from 50°C to 70°C, and for extra-heavy oil, it is above 100°C. For ordinary heavy oil, its flow effect can be better improved without too high temperature, while it’s totally different for super heavy oil. For which, higher temperature and other auxiliary viscosity reduction methods are needed to achieve better flow performance. Diesel oil reduce viscosity of heavy oil by similar solubility principle, but the demand for diesel oil is large. At 50°C, the viscosity of super heavy oil with 0.5% emulsion viscosity reducer added is 36 mPa·s, but the water content needs to reach above 30%.Oil-soluble viscosity reducer reduces viscosity by dissolving asphaltenes and resins and dismantling aggregate structure of heavy oil aromatic flakes.However, the dosage should reach about 20 %, so that the viscosity of super heavy oil can be reduced to the level of dilute oil. Overall, for developing super heavy oil, steam compound with oil soluble viscosity reducer can be taken into account at the early production stage, and the emulsion viscosity reducer can be used in the middle development stage and wellbore viscosity reduction and lifting process. Finally, for ordinary heavy oil, flue gas’s viscosity reduction effects, nitrogen and carbon dioxide are investigated. It is found that the viscosity reduction effect of carbon dioxide is the best, followed by flue gas and nitrogen. Considering the offshore gas source, cost and carbon emission requirements, it is recommended to use flue gas in the field. The research provides theoretical guidance and technical reference for development of different types of offshore heavy oil.
Experimental Study on Effects of Various Factors on Bottom-Water Reservoir Sweep Based on A Two-Dimensional Plate Physical Model
Authors: Zhang Zhang , Cai Hui , Quan Hong-hui , Tan Jie , Liu Chun-yan 
Published: November 2024

Abstract
Horizontal Wells have obvious technical advantages in developing bottom-water reservoirs. Scholars at home and abroad have conducted many physical simulation studies on the development mechanism of horizontal wells in bottom-water reservoirs. In this paper, physical simulation experiments of sweep coefficients with or without intercalation and different displacement velocities, different permeability, different fluid viscosity and different reservoir thickness are carried out. The water sweep of the horizontal well bottom under different conditions is analyzed. The experimental results show that the existence of intercalation can delay the water appearance time, increase the anhydrous oil recovery period, and increase the final recovery factor. Controlling the liquid production rate can alleviate the bottom water coning phenomenon, expand the sweep area and increase the ultimate recovery factor. When the reservoir permeability is too high, the flow resistance is small, the water appearance is early, the anhydrous oil production period is short, and the final recovery factor is low. When the reservoir oil viscosity is high, the water sweep area is small and the final recovery factor is low. As the thickness decreases, it becomes easier for water to break through and reach a smaller area, resulting in lower final oil production.
LSTM Recurrent Neural Network Based Method for Identification of PDC Drill Bit Operating Conditions and Its Application
Authors: Chen Chang-chang , Ji Guodong , Lv Zehao , Sun Yu-qi , Yu Jinping , Zhang Hong-yuan 
Published: November 2024

Abstract
PDC drill bit underground operating conditions identification is one of of the difficulties during the drilling operation. It is of great significant for the drilling improvement and accurate construction formation to accurately identify the complex operating conditions during drilling the operation such as PDC bit wearing and stick-slip vibration, etc. In this paper, data of relationship between torque, rate of penetration (ROP) signal and weight on bit (WOB), rev were obtained through lab simulation experiment, after which, a relationship database of torque, ROP signal and WOB, rev was established, a single-layer LSTM recurrent neural network (LSTM-RNN) was constructed, the number of neurons, batch size and optimizer type of LSTM layer were optimized. With BPTT algorithm, LSTM model was trained and tested on the training set containing 6000 groups of data, and achieved the goal of identifying the bit operation conditions against the input of WOB, torque, rev and ROP signal parameters. Based on this model, the PDC bit underground operating conditions identification software was compiled, and was connected to the logging unit to realize real-time identification of bit underground operating conditions, and field test application was successfully carried out in Mahu 1 Well Region. The research showed that the convergence speed was fast and the time cost was at the lowest when the number of neurons of LSTM model was 50, and that the optimized Adam optimizer model could meet the requirements of convergence speed and prediction accuracy with the lowest loss value. The classification accuracy of this model on the test set reached 94% and the accuracy of the prediction method was also verified by field test application. To sum up, the method of LSTM-RNN based PDC bit underground operating conditions real-time identification can better meet the requirements of accurate identification of PDC bit underground operating conditions in the practical drilling, and has guiding significance for the judgement of PDC bit operating conditions on site and formulation of scientific construction decisions.
Numerical Simulation of Gas-suspended Proppant Migration Based on Equivalent Principle
Authors: He Yuan , Yang Bin , Li Yue , Guo Yufan , Wei Hongyu , Yang Bo 
Published: November 2024

Abstract
The gas-suspended proppant is composed of conventional proppant particles and hydrophobic aerophilic coating. The surface coating changes the surface wettability of the proppant and increases the adhesion of the proppant surface to the gas, changing the traditional liquid-carried proppant into a gas-carried proppant. The sand carrying capacity of low concentration polymer fracturing fluid can be greatly improved by using air-suspended proppant carrying technology. At present, there is no numerical simulation method aiming at the migration law of gas-suspended proppant. Based on the principle of equivalent substitution, the density of gas and particles is set as the calculated equivalent density during simulation. Similarly, the diameter of gas-suspended proppant is set as the calculated equivalent diameter during simulation. Then computational fluid dynamics software was used to simulate the Euler-Euler method. It is found that Euler-Euler method can simulate the placement of gas-suspended proppant in fractures. Compared with conventional proppant, gas-suspended proppant is not easy to settle during migration, and the settling sand bed still has fluidity and can be re-suspended. When gas suspension proppant density increases, the proppant sedimentation trend increased. Increase the injection rate of proppant, and the shape of long and high sand dunes will become shorter and lower. As the sand rate increases, the height of the sand bank rapidly increases.
Study on Coalescence Characteristics and Mechanisms of Salt-laden Droplets Under Electric-magnetic Coupling Field
Authors: Li Mofan , Yang Donghai , Cai Liangyu , Miao Jiaxu , Liu Haotian , He Limin 
Published: November 2024

Abstract
Electric-magnetic coupling dehydration technology is a novel method that can significantly improve the efficiency of water-oil separation in water-in-oil (W/O) emulsions. However, the electric-magnetic coupling mechanisms and its influence on droplet coalescence have not been understood from a microscopic perspective, which has become a bottleneck restricting the progress of this technology. In this study, the high-speed microscopic experiment and molecular dynamics (MD) simulation were combined to study the kinetic properties of droplets coalescence under an electric-magnetic coupling field, and the potential mechanisms of electric-magnetic coupling field strengthening droplet coalescence were articulated from the perspective of salt ions migration and energy evolution. The results show that the experiment and simulation have excellent qualitative consistency. As water molecules polarise and migrate, the contact interface between adjacent droplets forms a cone tip during the approach process. The contact point of the droplet forms hydrogen bonds due to the mutual attraction of water molecules, which are then transformed into a continuously expanding liquid bridge. The salt ions in the droplet undergo migration deflection by the electric-magnetic coupling effect, which may affect the surface charge distribution of the droplets. During the process of droplet coalescence, strong electrostatic attraction occurs between molecules, leading to a significant increase in coulomb potential and dominating the overall potential energy variation. However, excessively small molecular spacing induces exchange repulsion, thereby reducing the van der Waals potential. The study results are of guiding significance for sounding droplet dynamics theory and guiding the research and development of electric-magnetic dehydration equipment.
Geological characteristics and volume fracturing adaptability of tight oil reservoirs in the Ordos Basin of China
Authors: Zhang Jinyuan , Chen Junbin , Lei Junjie , Xiong Jiao , Nie Xiangrong , Li Ziyan 
Published: November 2024

Abstract
In recent years, China’s dependence on foreign crude oil has gradually increased. The Ordos Basin has abundant oil, gas, and coal resource. Tight oil and shale reservoirs have become very important replacement resources. This article studies the geological characteristics and volume fracturing adaptability of the Yanchang Formation tight oil reservoir in the central region of the Ordos Basin, and uses X-ray diffraction experiments to analyze the mineral composition of the reservoir; Utilizing high-pressure mercury intrusion technology to achieve precise quantitative characterization of multi-scale pore structures in reservoirs; Using the Analytic Hierarchy Process, establish a numerical judgment matrix and factor weights to study the adaptability of volume fracturing in the region. The results indicate that the volume fracturing adaptability of tight oil reservoirs in the Ordos Basin is good.
Discussion on the Automatic Design Method of Well Trajectory for Cluster Well Platform
Authors: Chen Kuan 
Published: November 2024

Abstract
Shale oil and gas and other unconventional oil and gas resources adopt the development mode of cluster well group to achieve economic benefit development. Cluster well groups have the characteristics of small spacing between wellheads and limited space, and generally adjust trajectory parameters by designing individual artificial Wells one by one to meet the needs of geological target hitting and anti-collision and circumnavigation. Trajectory design affects the whole body, and the change of trajectory of one well causes all Wells on the same platform to readjust design parameters, which seriously affects the design efficiency. Therefore, on the basis of summarizing the experience of manual trajectory design, combining classical path planning algorithm and global planning algorithm, an automatic trajectory design model is established. A* path optimization algorithm and ant colony algorithm are used to construct the routing strategy method and rule set, and adapt the efficient manual guidance strategy for different risk classifications to achieve efficient automatic routing. A cluster well trajectory automatic design and routing module has been developed. Automatic trajectory design tested 15 platforms, with an average time of 60s. The efficiency of trajectory design was greatly improved, and it has important guiding significance for the development of automated drilling technology.
Research and Application of Electromagnetic Heating Device for Digital Well Site Crude Oil Export
Authors: Li Zhaohui , Gao Baoyuan , Tan Huan , Xu Jun 
Published: November 2024

Abstract
Most well sites have discontinued using the associated gas-fired furnaces in response to the current situation in the oil fields. Coal-fired heating furnaces are environmentally polluting and prohibited due to local environmental regulations. These two heating methods can cause high costs, poor heating efficiency, and environmental pollution, which cannot be achieved through remote digital monitoring. Research has been conducted on the digital electromagnetic heating device for crude oil in the well site, focusing on introducing its main components and functions, including the electromagnetic heating body, frequency conversion control cabinet, and digital remote monitoring terminal. This device provides one-way internal heating without a heat source, resulting in high thermal efficiency, safety, environmental friendliness, and energy conservation. It comprehensively addresses the drawbacks of traditional electric heating, characterized by low efficiency, susceptibility to damage, and difficult maintenance. In 2022, it was applied at three well sites in the Tongzhai operation area of the Third Oil Production Plant of Changqing Oilfield, replacing the existing gas-fired and coal-fired heating furnaces to heat crude oil, as well as heating the heating belt and various electric heating pipes. This device is highly efficient, safe, environmentally friendly, and energy-saving. Additionally, the temperature and pressure of electromagnetic heating crude oil can be digitally and remotely monitored.
Research on oil well production analysis based on long-term slow-release tracer
Authors: Xu Gang , Wang Kongyang , Yan Qiehai , Li Jin , Zhao Kexian , Wang Xiaobo , Dong Changyin , Xue Dongyu 
Published: November 2024

Abstract
Downhole monitoring the production profile is crucial for the development of oil and gas reservoirs. Currently, the commonly methods for monitoring the production profile include logging tools and using tracer monitoring. The tracer monitoring method is more popular in oil field operations due to its wide applicability, simple process, low cost, low risk, and long monitoring time. However, compared to traditional logging tool monitoring methods, tracer monitoring has drawbacks such as data lag, difficulty in downhole installation, and unstable long-term effects. Bohai Oilfield has developed a new type of solid tracer and solved the problem of downhole installation by improving the structure of the downhole screen tube. This tracer uses polymer material as the skeleton. After entering the designated position, the internal tracer can slowly diffuse into the solvent through the pores in the skeleton, achieving slow release and long-term monitoring of the production profile of the oil well. In 2023, this new type was first applied in the D6 well in Bohai Sea, and a half month stable production stage liquid production profile was obtained through sampling. The monitoring results showed that: (1) Solid slow-release tracer monitoring technology can continuously obtain production layer information in complex environments and can be used for short-term rapid water exploration and long-term water production monitoring, identifying water breakthrough time and main water breakthrough location, (2) The distance between water injection well and D6 production wells is small, and the water injection volume in the injection wells is large. The tracer monitoring results show that there is a certain degree of water flooding in all 6 sections of each test layer, (3) The first test layer is the main liquid production section, the first and sixth test layers are the main oil production sections, and the first and second test layers are the main water production sections. The research results can determine the oil and water production situation of each section of oil well, identify the water breakthrough time and water outlet position, and provide a basis for the next development adjustment.
Application of 3D Geological Modeling Technology for Single Sand Body in Block S
Authors: Gao Hui-ying , Li Jian-qi , Gao Ruan , Leng Xiao-yong , Zhang Mei , Fan Cai-xia 
Published: November 2024

Abstract
The P oil layer is generally in a medium to high water cut period, with scattered macroscopic residual oil distribution. The reserves are mainly distributed in the microfacies of river sand bodies, and the main layer is severely flooded with water, resulting in ineffective circulation in some areas. Therefore, it is necessary to tackle the modeling technology within the layer and describe the remaining oil within the layer to meet the needs of tapping the potential of remaining oil during the high water cut period. This article takes the establishment of a three-dimensional geological model of a single sand body within the S block layer as an example. Based on the establishment of a fine structural model, the “plane and vertical dual control” modeling method is used. The implementation method is: controlling the range of sedimentary facies maps → using the top surface of the sand body as the top depth of the river channel → controlling the vertical shape of the river channel through the facies controlled sandstone contour map, thereby achieving the vertical shape of the river channel through the facies controlled sandstone contour map, and establishing a three-dimensional sedimentary facies model of a single sand body. Optimize the method for characterizing interlayers, achieve modeling of single sand body interlayers, and perform random simulation interpolation in phases to obtain attribute models. The use of a single sand body model within a layer can visually display the three-dimensional channel morphology and classify the identified connected bodies within the study area. The upscaling method of sedimentary facies models with irregular boundaries greatly reduces the number of model grids and provides a relatively refined geological model for numerical simulation.
Research and Field Application on Extreme Subdivision Water Injection Technology for Low Permeability Reservoirs
Authors: Shao Zhiyong 
Published: November 2024

Abstract
Low permeability Block A is about to enter the development phase of extremely high water cut. Due to the low overall recovery degree and residual oil scattered sporadically, the efficient development meets more difficulty and conventional residual oil analysis and adjustment methods cannot fulfil the current needs of precise development. To enhance the reservoir utilization degree, we conduct extremely concise zonal water injection experiment from three aspects: sand body description, policies establishment, and proper technique application. In terms of sand body description, four types of sand-body distribution patterns were summarized through fine characterization of vertical, planar, and spatial single sand bodies, clarifying the origin and potential distribution of residual oil. In terms of development policy, numerical simulation and reservoir engineering methods have been comprehensively applied to determine the subdivision combination of injection layers and reasonable water allocation boundaries, and subdivision principles have been established, considering single septation to thin and thick layer with combining enhancing -controlling. In terms of supporting technology, we have studied the small space subdivision process of small compartments, optimized the testing and adjustment methods, and finally achieved accurate separation, strict clamping, and accurate matching of water injection layers. Through the research and practice, it realized the finest septation of the water injection to extremely enhance the subdivision degree and the efficiency of the injection. It also have strengthened the utilization of thin and poor layers and effectively controlled the decline.
Mechanism Research and Identification Method of Low Resistivity Gas Layers in the M block of Algeria
Authors: Wang Kun , Yang Yuan-Qi , Xu Chao-Hui , Cheng Xiao-Dong , Chen Lei , Niu Hu-Lin 
Published: November 2024

Abstract
The M block in Algeria is located in the southern Sahara platform, with oil and gas reservoirs mainly composed of river-glacial marine facies, fluvial and shallow marine fine sandstones. The pore structure is complex, and the difference in resistivity logging between gas layers and water layers is not significant, resulting in difficulties in identifying and evaluating hydrocarbon zone and the occurrence of reservoir omission. Based on geological, mud logging, core experimental data, logging, formation water analysis and testing data together, the formation mechanism of low resistivity hydrocarbon zone and the response characteristics of logging curves were generalised. The research suggests that the main factors causing low resistivity in this area are strong heterogeneity, high formation water salinity, high shale content, etc. On this basis, in response to the difficulty of identifying low resistivity gas layers, three methods of assessment were constructed: resistivity reduction rate factor method, porosity curve differentiation technique method and double porosity overlap method, which can quickly identify low resistivity gas layers. The oil testing results have verified that this method significantly improves the interpretation accuracy, with a 17.2% increase in accuracy and good results. The test results show that the method can greatly improve the interpretation accuracy with current accuracy 89.1% and the method turns out to be effective. Based on the above methods, the distribution law of low resistivity oil and gas layers in the study area has been clarified, and favorable zones have been discovered, providing strong technical support for increasing reserves and production in the area.