检索结果-内蒙古大学图书馆

Molecular Insights into the High Temperature Resistance Mechanism of Anionic Copolymers with Cyclic Side Groups as a Filtration Control Additive in Water-Based Drilling Fluids

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Wang, Xiaohui Li, Hangyu Geng, Yuan Zhang, Zhilei Yan, Zhiyuan Hu, Min Huang, Xianbin Qi, Yingxiang Xu, Jiafang Qingdao266580 China National Engineering Research Center for Oil & Gas Drilling and Completion Technology Qingdao266580 China Ministry of Education Qingdao266580 China CNPC Engineering Technology Research and Development Company Limited Beijing102206 China Petrochina Planning and Engineering Institude Beijing100083 China

The high temperature and high pressure(HTHP) environment in deep well drilling process has brought new challenges to temperature resistance ability of drilling fluid additives. Understanding the dynamic behaviour of the agents in HTHP can provide theory basis for the design and development of novel additives. In this work, DSA-111(dimethylamino: benzenesulfonic acid: carboxyl is 1:1:1), DSA-211(dimethylamino: benzenesulfonic acid: carboxyl is 2:1:1), 1,7-dimethylamino-octane, 1,7-dibenzenesulfonic acid-octane and 1,2,6,7-tetracarboxyheptane has been designed and constructed based on the molecular structure of anionic copolymers with cyclic side groups(DSA). Molecular dynamic simulation(MD) applied to study the dynamic behaviour of polymer/water binary system and polymer/water/bentonite ternary system respectively. Result show that: temperature is the main factor that influence the behaviour of polymer, while the pressure effect is relatively small;dimethylamino is acted as tentacle to absorbed on the surface of montmorillonite, while the Benzenesulfonic acid group is to prevent backbone bending and cooperated with Carboxyl group to guarantee the polymer's solubility in HTHP;When the ratio of dimethylamino: benzene sulfonic acid group: carboxyl group is 2:1:1, the adsorption effect of DSA can be guaranteed and the hydrogen bonding network structure in aqueous phase is relatively stable. This study provides important insights into the temperature resistance mechanism of DSA treatment agents and the development of new high temperature treatment agents. © 2024, The Authors. All rights reserved.

关键词： Molecular dynamics

Flow numerical simulation of tubing or casing leakage in gas well

学校读者我要写书评

暂无评论

Flow numerical simulation of tubing or casing leakage in gas...

Abu Dhabi International Petroleum Exhibition and Conference 2020, ADIP 2020

作者： Zhang, Hong Yuan, Guangjie Li, Guotao Li, Jingcui Wan, Jifang Fu, Pan CNPC Engineering Technology R&D Company Limited Research Institute of Petroleum Exploration and Development CNPC Engineering Technology R&D Company Limited

ISBN: (纸本)9781613997345

Tubing or casing leakage of HTHP gas wells and underground gas storage wells affects wellbore integrity adversely. The wellbore micro-leakage detection technology can detect tiny fluid leakage in time and is of great significance to avoid malignant gas leakage accident. The theoretical basis of wellbore microleakage detection technology is characterizing the leakage flow field. To reveal the flow characteristics of gas leakage due to tubing and casing cracks and perforations, a CFD model of gas aperture leak has been established and flow field numerical simulation of high-speed and high-pressure gas outflow through aperture was conducted. The standard k-e turbulence model was used to calculate and analyze the pressure and velocity distribution of the steady flow field. In addition, a time step was set on the steady-state model and the Scale-Adaptive Simulation (SAS) model was adopted to simulate the transient flow field with the initial conditions of the steady-state simulation results. The effects of the shape and size of the leakage hole, the pressure inside the pipe, and the medium in the outer annular space on the flow field were analyzed. The results show that obvious turbulence disturbance appears near the inlet of the leakage hole and supersonic under-expansion jet forms near the outlet of the leakage hole under the gas well working conditions, creating the expansion wave and shock wave. The flow velocity of gas leakage through the circular hole is the highest, while that of the slot hole is the lowest under the same conditions. The larger the leakage aperture is, the greater the pressure difference between inside and outside of the pipe is, and the more drastic variation of gas velocity in the leakage hole. The method and results provide theoretical guidance for the microleakage detection technology of gas well wellbore. © 2020, Society of Petroleum Engineers

关键词： Flow fields

A Seepage mathematical model for fractured wells of coalbed methane reservoirs and the corresponding pressure response feature 6

学校读者我要写书评

暂无评论

A Seepage mathematical model for fractured wells of coalbed ...

2020 6th International Conference on Environmental Science and Material Application, ESMA 2020

作者： Liu, Chunchun Zhang, Cong Xu, Yanmei Cui, Xinrui Huang, Weigang He, Aigu Wang, Xiangyan Liu, Yishan Wang, Jigang Shanxi CBM Exploration and Development Branch PetroChina Oilfield Company Shanxi Jincheng048000 China Research Institute of Petroleum Exploration and Development Beijing10083 China CNPC Engineering Technology RandD Company Limited Beijing102206 China

Coalbed fracturing is one of the important engineering and technical means of coalbed methane stimulation. To establish the seepage model of coalbed gas fracturing well is the key scientific problem to effectively evaluate the fracturing effect. Therefore, based on the micro pore structure of coalbed methane, this paper constructs the physical model of three porosity and two permeability, the mathematical model of seepage and the mathematical model of bottom hole pressure response, and analyzes the key factors affecting the dynamic response characteristics of pressure. The results show that diffusion coefficient, channeling coefficient, reservoir volume ratio and conductivity have different effects on the bottom hole pressure of the vertical well of three hole and two permeability fracturing. The results of this paper have certain guiding significance for the drainage and production capacity prediction of coalbed methane. © Published under licence by IOP Publishing Ltd.

关键词： Porosity

Micro-Nano Polymer Microspheres as a Plugging Agent in Oil-Based Drilling Fluid

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Zhao, Zhen Sun, Jinsheng Liu, Fan Cheng, Rongchao Bai, Yingrui Wang, Ren Wang, Jintang Geng, Yuan Jin, Yeliang Ma, Zhihu CNPC Engineering Technology R&D Company Limited Beijing102206 China Research Institute of Petroleum Exploration &Development Beijing100083 China China Department of Petroleum Engineering China University of Petroleum Beijing China

The wellbore instability of shale formations with micro fractures was mainly ascribed to drilling fluid invasion and pressure transmission during drilling using oil-based drilling fluids (OBDF). Nano-plugging agents or micro-plugging agents at present only match a narrow size range of nanopores or microcracks. Plugging agents with good suitability to multidimensional fractures used in OBDF are lacking. This paper synthesized micro-nano polymer microsphere dispersion (PMD) with a solid content of 30% through inverse emulsion polymerization. PMs had good wettability for water in the oil environment. The filtration of the emulsion with 4% PMD dropped the filtration through 0.1~3 μm filters to within 14 mL while the emulsion with 1% CaCO3 only plugged the filter with a pore size of 3 μm. Hydrophilic PMs with a wide size distribution have excellent suitability with multi-scale pores or cracks. PMs could reduce the filtration of OBDF after aging at 120 and 150℃ without significantly influencing their rheology and electrical stability. Based on Darcy’s law, the HTHP mud cake permeability calculated decreased by half with the addition of PMD at 120 and 150℃. Moreover, the addition of PMD could decline the disc HTHP filtration by 100~50% when the disc diameter was 5~120 μm respectively. Compared with CaCO3, the PMD showed superior plugging performance and self-suitability when plugging 5~120 μm discs. Micro-nano PMs could interact with organic clays through hydrogen bonds to form thinner and denser mud cakes. They could also form hydrogen bonds with the formation surface. PMs could enter, aggregate and arrange tightly at multi-scale pores or cracks owing to their wide size distribution. In addition, they formed a dense plugging layer and prevent the filtration from invading the formation. The PMD with good compatibility, suitability and plugging performance has a promising application prospect in shale oil and gas exploration. © 2023, The Authors. All rights reserved.

关键词： Emulsification

Productivity Comparison between Steam Injection and Electrical Heating in Oil Shale In-Situ Exploitation

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Lei, Zhihong Zhang, Yulong Yang, Zijiang Shi, Yu Zhang, Hongyuan Li, Xiaojiang Cui, Qiliang Faculty of Geosciences and Environmental Engineering Southwest Jiaotong University Sichuan Chengdu611756 China CNPC Engineering Technology Research and Development Company Limited Beijing102206 China SINOPEC Research Institute of Petroleum Engineering Co. Ltd Beijing102206 China

Oil shale is an important alternative resource to the conventional oil and gas because of its rich reserves. The in-situ heating exploitation is the most promising method to produce oil from the oil shale, mainly including electrical heating and steam injection heating. However, to the best of our knowledge, a comprehensive comparison between these two kinds of heating methods is still absent, thus the comparison is necessarily conducted to provide suggestions on how to select heating modes for the oil shale in-situ exploitation. On this basis, a systematic comparison is presented between in-situ steam heating and electrical heating, including physical and process parameters, and then sensitivity analysis and optimization on key parameters are carried out. Simulation results show that steam injection heating is superior to electrical heating in output, energy consumption and production cycle. The flow rate and temperature of the injected steam and the specific heat capacity of oil shale are sensitive to productivity. The production will be increased with larger injection flow rate and temperature. The thermal conductivity and porosity are less sensitive to the mining efficiency compared to the injection flow rate and temperature. At the same time, different well pattern structures also have an impact on productivity, and the hexagonal well pattern has better productivity benefits than the triangular and quadrilateral well patterns. In the simulation case of this paper, the most conducive parameters for exploitation were derived as injection flow rate 0.28 kg/s, injection temperature 650℃, specific heat capacity 1.5 kJ/(kg×K), thermal conductivity 0.5 W/(m×K), porosity 0.05. These results are expected to provide theoretical suggestions for improving the productivity efficiency of oil shale in-situ exploitation. © 2023, The Authors. All rights reserved.

关键词： Sensitivity analysis

Performance Study of Modified Aluminate Cementite Under In-Situ Conversion Conditions of Shale Oil

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Zhang, Jian Wan, Xiangchen Chen, Xiaorong Drilling & Production Engineering Technology Research Institute CNPC Chuanqing Drilling Engineering Company Limited Shaanxi Xi’an710018 China National Engineering Laboratory for Exploration and Development of Low-Permeability Oil & Gas Fields Shaanxi Xi’an710018 China

The resource potential of in-situ conversion of shale oil is enormous, and it is a strategic alternative resource for China's oil and gas industry. However, extreme high temperatures under in-situ conversion conditions of low maturity shale oil can lead to a decline in the mechanical strength of cement. In this paper, the influence of modified sodium hexametaphosphate on the hydration behavior of aluminate cement and its application performance at 650 ℃ was systematically studied, and its macro performance and microstructure were deeply explored. As a result, it was found that the sodium hexametaphosphate can significantly reduce the permeability of aluminate mudstone, but not significantly improve the strength, at the same time, it was found that the permeability of aluminate stone modified by micro silicon composite sodium hexametaphosphate is significantly reduced, and the compressive strength is increased. After treated at 650 ℃, the compressive strength of 5.0% sodium hexametaphosphate modified aluminate stone is the highest (47.19MPa), while the compressive strength of micro silicon composite sodium hexametaphosphate modified aluminate mudstone shows a downward trend. The aluminate brine debris has obvious transformation of hydration products before and after treatment at 650 ℃, including mainly C3AH6 and AH3 into C12A7 and CA. Among them, C3AH6 and AH3 mainly undergo thermal decomposition at 180 ~ 400 ℃, and the pores of cement stone increase attribute to the transformation of crystal form. The C2ASH8 generated by aluminate stone at 50 ℃ due to micro silicon is helpful to improve the microstructure. But, the decomposition of C2ASH8 after 650 ℃ treatment will also lead to the increase of cement paste pores. © 2023, The Authors. All rights reserved.

关键词： Compressive strength

Lithology Identification of Improved Model based on DeepLabv3 + Deep Convolutional Neural Network

学校读者我要写书评

暂无评论

Lithology Identification of Improved Model based on DeepLabv...

New Trends in Computational Intelligence (NTCI), International Conference on

作者： Ju Wang Senlin Yin Zhangming Hu Kai Bai College of Computer Science and Technology Yangtze University Hubei China Research Institute of Mud Logging Technology and Engineering Yangtze University Hubei China Hubei Provincial Key Laboratory of Southern Complex Shale Oil and Gas Geology and Development Hubei Province Wuhan China Engineering and Technology Division of CNPC Xibu Drilling Engineering Company Limited

ISBN: (数字)9798331517021

ISBN: (纸本)9798331517038

Aiming at the complexity of outcrop lithology identification, an improved outcrop lithology identification algorithm based on DeepLabv3 + is proposed. We use the Xception network replaced by the MobileNetV2 module to enhance the ability to extract lithologic features and make the model more lightweight. In order to segment pixels more accurately, the CA (Coordinate attention) attention mechanism is introduced, so that the improved backbone network can extract lithologic features more accurately in complex environments. The experimental results show that compared with the traditional DeepLabv3 +, the accuracy of the improved algorithm is increased by 1.08 percentage points, the MP A is increased by 2.4 percentage points, and the average classification accuracy is 94.86 %. Compared with other mainstream semantic segmentation models, all aspects of performance are more prominent.

关键词： Accuracy Attention mechanisms Computational modeling Semantic segmentation Feature extraction Market research Complexity theory Classification algorithms Convolutional neural networks Computational intelligence

Transformation mechanism of muddy carbonate rock by the coupling of bioturbation and diagenesis:A case study of the Cretaceous of the Mesopotamia Basin in the Middle East

学校读者我要写书评

暂无评论

Petroleum Exploration and development 2021年第6期48卷 1367-1382页

作者： YE Yu LI Fengfeng SONG Xinmin GUO Rui Research Institute of Petroleum Exploration&Development PetroChinaBeijing 100083China CNPC Engineering Technology R&D Company Limited Beijing 102206China

The transformation mechanism of muddy carbonate rock by the coupling of bioturbation and diagenesis was stud-ied based on core,cast thin section and physical property data of Cretaceous strata in the Mesopotamia Basin,the Middle *** are 3 ways of biological transformation of rocks:(1)The living creatures transformed formations mechanically to make the rocks looser and intergranular pores increase.(2)After formation,burrows were backfilled with coarse-grained debris,and then unsaturated fluid infiltrated into the burrows during the penecontemporaneous period,resulting in dissolution.(3)Chemical alteration occurred in abandoned burrows and dolomitization produced a large number of intercrystalline ***·coupling of bioturbation and dissolution occurred mainly in the penecontemporaneous phase,and was controlled by rock type,sea level decline,burrow abundance,infillings,and water environment *** the burrows had better physical properties than the matrix,unsaturated fluid preferentially migrated along the burrows,leading to dissolution and expansion of the burrows first and then dissolution of the *** coupling of bioturbation and dolomitization occurred mainly in the burial *** rich organic matter and reducing bacteria in the burrow provided material basis,reducing conditions and alkaline envi-ronment for *** metasomatism in the penecontemporaneous period had little effect on the physical properties of the *** the burrows were se parated from the deposition interface,equimolar metasomatism occurred in the burrows in a closed environment,forming euhedral fine-crystalline dolomite with intercrystalline *** transformation degree of bioturbation to muddy carbonate reservoir depends on rock type,density,connectivity,infillings and structure of the *** the increase of the carbonate mud content,the im provement to rock physical properties by bioturbation be-comes more *** the burrows are filled with co

关键词： bioturbation muddy carbonate rocks Mesopotamia Basin Cretaceous diagenesis dissolution dolomitization

EBFT: Efficient BFT Consensus through Shortcut Replies

学校读者我要写书评

暂无评论

EBFT: Efficient BFT Consensus through Shortcut Replies

IEEE International Conference on Big Data and Cloud Computing (BdCloud)

作者： Qingsheng Lei Yongjun Xia Qitao Guo Rui Hao Xiaohai Dai Weiqi Dai State Grid Hubei Electric Power Company Limited Economic & Technology Research Institute Hubei Central China Technology Development of Electric Power Company Limited Software Institute Nanjing University School of Computer Science and Technology Huazhong University of Science and Technology School of Cyber Science and Engineering Huazhong University of Science and Technology

As the core building block of blockchain technology, Byzantine Fault Tolerance (BFT) consensus has gathered renewed attention during the past decade. A large number of BFT consensus protocols have been proposed since its inception in the 1980s, the best-known of which is Practical Byzantine Fault Tolerance (PBFT). Generally speaking, PBFT consists of two sub-protocols: normal-case protocol and view-change protocol. However, it requires $7 \delta$ for a client to commit a request in the normal case, where $\delta$ represents the actual network delay. If a request happens to go through the view change process, it will take additional $7 \delta$ for a client to commit a request. To reduce the consensus latency, we propose a novel BFT consensus protocol named EBFT, which introduces the shortcut replies to the consensus design. With these shortcut replies, EBFT reduces the normal-case latency and view-change latency to $5 \delta$ and $2 \delta$, respectively. Extensive experiments are conducted to evaluate EBFT, whose results demonstrate its effectiveness.

关键词：