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SPE/AAPG/SEG Unconventional resources technology Conference 2019, UrTC 2019

作者： Mu, Lingyu Liao, Xinwei Zhao, Xiaoliang Zhang, Jingtian Zou, Jiandong Chu, Hongyang Shang, Xiongtao Beijing China CNPC Engineering Technology R and D Company Limited Beijing China

due to the special micro-pore structure and the seepage law of tight reservoirs, the research on the development of tight oil is quite different from conventional reservoirs. For the tight oil reservoirs recovered with the gas injection, the gas breakthrough is an eternal theme as a result of the preferable mobility of the gas and the strong heterogeneity of the reservoirs. It is extremely important to evaluate the sweep efficiency. Based on the stream-tube method and the non-darcy theory, this paper establishes a rapid evaluation technique of sweep efficiency considering the mechanism of the gas flooding and the seepage characteristics of the tight oil reservoir. Firstly, the relative permeability under different miscible condition are determined through the revised Coats model. Besides, the Todd-Longstaff model is adopted to describe the varying viscosities of oil and gas. Secondly, the stream-tube model of the inverted nine-spot well pattern with fracture is established. Next, the seepage equations of oil and gas in the stream-tube is constructed considering the threshold pressure and the variation of the viscosity and relative permeability. Then, the sweep efficiency is obtained by solving these equations. Furthermore, an application example for evaluating the sweep efficiency is presented and sensitivity analyses are conducted to study the effect of the viscosity, pressure difference, fracture permeability and well spacing taking the case of a real tight reservoir. Through the analyses, it can be concluded that the factors have remarkable impacts on the sweep efficiency. The threshold pressure increases the resistance and reduces the flow rate, leading to a lower sweep of the injected gas. Even worse, the excessive threshold pressure results in that the effective displacement cannot be established. The fracture greatly shortened the breakthrough time and result in early channeling of the injected gas. The sweep efficiency is improved through the increase of the

关键词： Gases

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Sequential Optimization-Based Parameter Identification for Multi-Timescale Electromechanical Model of Battery

SSRN

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SSrN 2024年

作者： Choi, Hyunhee Choi, Yong Hwan Youn, Byeng d. Lee, Guesuk Department of Mechanical Engineering Seoul National University Seoul08826 Korea Republic of R&D Division Hyundai Motor Company Hwaseong18280 Korea Republic of Institute of Advanced Machines and Design Seoul National University Seoul08826 Korea Republic of OnePredict Inc. Seoul06160 Korea Republic of Korea Electronics Technology Institute Gyeonggi-do 13509 Korea Republic of

In the battery systems within electric vehicles, battery modules/packs are fixed, imposing mechanical stress due to the swelling effect. This stress significantly impacts the reliability of the battery cells and the safety design of external structures. To achieve an ideal stress condition internally, it is crucial for the battery system model to accurately simulate electromechanical behaviors. However, existing research on mechanical stress of battery systems has primarily considered only the viscoelastic properties or the interaction of swelling with the state of charge. Additionally, identifying these characteristic parameters necessitates conducting specific experiments or performing optimization-based parameter identification. These identification methods require either extensive experiments or the estimation of numerous parameters, demanding time and cost. This study proposes a multi-timescale electromechanical model that includes degradation, along with an efficient sequential optimization-based method for parameter estimation. The proposed method requires only a single experiment in a pressurized setup, significantly reducing costs in the development phase. The parameter identification process is divided into two timescales: short-term and long-term. The short-term identification enhances accuracy and computation time by sequentially estimating parameters using physics from internal structure. The long-term identification reflects model degradation through cycle-based updates. The validation process confirms the efficiency of our proposed method in parameter identification compared to existing techniques and highlights the importance of update due to degradation. © 2024, The Authors. All rights reserved.

关键词： Lithium-ion batteries

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Sealing analysis of cement plug in offshore abandoned wells 20th

Sealing analysis of cement plug in offshore abandoned wells

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20th Chinese Materials Conference, CMC 2019

作者： Tang, Geng Yan, Hui Li, Jun Song, Xuefeng Zhang, Xin Guo, Xueli Petro China Southwest Oil & Gasfield Company Chengdu610000 China China University of Petroleum-Beijing Beijing102249 China China University of Petroleum-Beijing at Karamay Karamay834000 China CNOOC Safety Technology Service Co. Ltd. Tianjin 300450 China CNPC Engineering technology R&D Company Limited Beijing102206 China

ISBN: (纸本)9783035715668

A three-dimensional finite element model of stratum-cement ring-casing-cement plug was established for the failure analysis of the cement plug seal in the abandoned oil and gas wells. The mechanical parameters, length, bottom fluid pressure and casing swaging length of the cement plug under non-uniform ground stress conditions were analyzed. The results showed that when the bottom of the cement plug was subjected to fluid pressure, the stress at the interface between the cement plug and the casing increased, and thereby the cement plug at the bottom and the cementation of the casing failed, resulting in a the decrease in the sealing performance of the cement plug, which may be sealed under fluid corrosion. As the modulus of elasticity and the radius of the cement plug increased, the cement plug stress and the cement failure length increased. As the cement plug length increased, the cement plug stress and the cement failure length decreased, while Poissons ratio for the cem ent plug stress and the cement failure length increased. The increase of the bottom fluid pressure could increase the cement plug stress and the cementation failure length. In the abandoned well, where the casing was forged and then grinded after the casing was forged, the length of the casing milling increased, the plug stress of cement reduced. These findings can provide insightful potentials for the parameters of cement plugs when the cement plugs are closed in the offshore oil and gas wells. © 2020 Trans Tech Publications Ltd, Switzerland.

关键词： Cements

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The fundamental work to the pre-frac evaluation of deep shale reservoir: Evaluating reservoir heterogeneity based on principal components analysis and artificial neural network

The fundamental work to the pre-frac evaluation of deep shal...

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International Petroleum technology Conference 2019, IPTC 2019

作者： Zhai, Wenbao Li, Jun Xi, Yan Liu, Gonghui Yang, Hongwei Jiang, Hailong Zhou, Yingcao China University of Petroleum China CNPC Engineering Technology R and D Company Limited China

ISBN: (纸本)9781613996195

Shale reservoir heterogeneity is more and more focused during shale gas development, especially deep shale gas reservoir buried in the depth of over 3,500 m. However, the evaluation methods of heterogeneity are not always available and poor applicability. In this study, a Principle Component Analysis (PCA)-Artificial Neural Network (ANN) model was presented. The evaluation steps of the model were also given. The validation of the model was confirmed by using a deep shale gas well located in Weiyuan area of Sichuan Basin, China. The results of the validation show that the model presented in this study can be in good agreement with the assessed values of heterogeneity obtained from microseimic events. The developed model's effectiveness was tested by comparing the results acquired from ANN without PCA, where the PCA reduces the dimension of input parameters to improve results of PCA-ANN over 80%. Therefore, the PCA-ANN model can help the engineers evaluate the deep shale reservoir heterogeneity, which provides a tool to give preliminary recommendations of the likelihood of improving the effectiveness of hydraulic fracturing. Implementation of the proposed model can serve as a cost-effective and reliable alternative for the deep shale reservoir. © 2019, International Petroleum technology Conference

关键词： Neural networks

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Characteristics and Mechanism of Upper Permian reef reservoirs in the Eastern Longgang Area, Northeastern Sichuan Basin, China

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Petroleum 2020年第2期6卷 130-137页

作者： Lei Tan Hong Liu Yuzhe Tang Bing Luo Ya Zhang Yuran Yang Yisha Liao Weifeng du Xiran Yang School of Geosciences and Technology Southwest Petroleum UniversityChengdu610500China Beijing Petroleum Machinery Co. CNPC Engineering Technology R&D Company LimitedBeijing102206China The Institute of Exploration and Development of Southwest Oil and Gas Field Branch PetroChinaChengdu610059China Chongqing Gas Field Southwest Oil&Gas Field CompanyPetroChinaChongqing400021China Bureau of Geophysical Prospecting China National Petroleum Corp Zhuozhou072750China Northwest Sichuan Gas Field Southwest Oil&Gas Field CompanyPetroChinaJiangyou621709China

As a typical kind of lithologic reservoirs,reef reservoirs are generally featured by their large single-well reservoir thickness,good reservoir physical properties,and high gas well *** Upper Permian Changxing Formation is an important natural gas exploration target in the Sichuan Basin,which hosts a large reef gas reservoir and is mainly distributed along the Kaijiang-Liangping *** analyses are implemented to investigate reservoir characteristics and identify controlling factors of reef reservoirs in Changxing Formation in the Eastern Longgang Area,Northeastern Sichuan Basin,including core,logging,and seismic data *** Formation reservoirs in the study area mainly occur in the reef-shoal complex,which are featured by wide distribution,large thickness and generally good physical *** rocks are dominantly composed of bioclastic dolomite and silty-fine dolomite(with grain phantom structure),while the main reservoir space consists of residual intergranular pores,intergranular dissolution pores,and karst *** the seismic profiles,typical mound-shaped chaotic reflections can be clearly *** is suggested by the main reservoir development controlling factor analysis that the distributions of reef reservoirs are typically controlled by sedimentary facies belts,while the scale of the reef-shoal complex is determined by the pene-sedimentary *** can not only significantly preserve the primary pores but also enhance the permeability of ***,karstification is the key to high-quality reef-shoal reservoirs.

关键词： Changxing formation reef reservoir characteristics Essential factors Eastern longgang

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Fused Tapered Fan-in/Fan-out device of 6-Mode 7-Core Fiber Based On OM3 Multimode Fiber

Fused Tapered Fan-in/Fan-out Device of 6-Mode 7-Core Fiber B...

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Asia Communications and Photonics Conference and Exhibition (ACP)

作者： Chen Yang Haoze du Yuanhui Shao Fengming Zhang Zhuyixiao Liu Senyu Zhang Zhiyong Zhao Ming Tang State Key Laboratory of Optical Fiber and Cable Manufacture Technology Yangtze Optical Fiber and Cable Joint Stock Limited Company (YOFC) R&D Center & Optics Valley Laboratory Wuhan China Wuhan National Lab for Optoelectronics (WNLO) & National Engineering Laboratory for Next Generation Internet Access System School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan China

Fused tapered Fan-in/Fan-out devices of few-mode multi-core fiber have received attentions in recent ten years. Most devices are based on special designed fibers which are called “bridge fiber”. A low insertion loss and low-cost Fan-in/Fan-out device using OM3 fiber as the bridge fiber is fabricated and demonstrated in this paper. The insertion losses of LPOl, LPlla, LPllb, and LP2la are less than 1dB, and the insertion loss of LP2lb and LP02 are 2.02dB and 2.2dB.

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Basic principles of elastic two-phase method for gas wells and the issues to be noted and its simplified applications and suggestions

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Natural Gas Industry 2025年第5期45卷 79-86页

作者： Sun, Hedong Zhu, Songbai Yao, Chao Zhao, Longfei Cao, Wen Cao, Wen Yang, Xiaoying Li, Mengqin PetroChina Research Institute of Petroleum Exploration & Development Beijing100083 China PetroChina Tarim Oilfield Company Xinjiang Korla841000 China CNPC R&D Center for Ultra-Deep Complex Oil & Gas Reservoir Exploration and Development Xinjiang Korla841000 China Xinjiang Engineering Research Center for Ultra-deep Complex Reservoir Exploration and Development Xinjiang Korla841000 China

The elastic two-phase method, as a way to calculate the geological reserves and technically recoverable reserves within the single-well control range of low-permeability gas reservoir by gas driving, plays an important role in estimating the controlled reserves of exploration wells in the natural gas exploration stage or verifying the reserves of gas reservoirs in the early stage of production. However, the applicable conditions of the commonly used simplified formulas are not defined, which causes deviations in the single-well controlled reserves of gas well. Based on the dimensionless analytical solution of a vertical well in a bounded gas reservoir during the pseudo-steady flow stage, this paper derives and presents in detail the dimensional calculation formulas in the forms of pressure method, pressure square method, pseudo-pressure method and normalized pseudo-pressure method of the elastic two-phase method for gas wells. In addition, the problems and their solutions in the process of formula simplification are analyzed. Finally, comprehensive verification is carried out based on simulation case and field case, respectively. The following results are obtained. First, when the pressure is lower than 20.1 MPa, the gas compressibility factor can be simplified to 1/pi, and the calculation formula of the elastic two-phase method can be simplified. Second, when the pressure is higher than 20.1 MPa, the original pressure should be directly used or the value of the gas compressibility factor under the condition of the maximum pressure should be adopted, or the combination of 1/pi and correction factor should be used. Third, the (normalized) pseudo-pressure method is the preferred method, and the pressure method should not be used in the case of low pressure ( © 2025 Natural Gas Industry Journal Agency. All rights reserved.

关键词： Gas industry

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Study on the effect of oligomer silicone surfactant on the properties of drilling fluids

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IOP Conference Series: Earth and Environmental Science 2022年第1期983卷

作者： Jie Zhang Long Li Nanxing Xie Xuyang Yao Zhiliang Zhao CNPC Engineering Technology R&D Company Limited Beijing 102206 China PetroChina Southwest Oil & Gas Field Company China PetroChina Xinjiang Oil & Gas Field Company China

due to small hole roar, most of low-permeability gas reservoirs are water wetting, and the capillary effect is very prominent, resulting in water blocking damage in the process of exploitation for natural gas. A new kind of oligomer silicone surfactant (OSSF) was developed, and the physical and chemical properties of oligomer silicone surfactant were evaluated. The experimental results indicated that the critical micelle concentration of OSSF was 0.418×10-3 mol/L, and the critical surface tension of OSSF was 20.631 mN/m. OSSF could be adsorbed directionally at the water-rock pore interface, and the cores adsorbed with OSSF should reverse from water wetting to oil wetting or gas wetting. OSSF had good compatibility with sulphonated polymer mud. OSSF could play an important role in unlocking water blocking damage to increase production and efficiency.

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Optimal utilization of frequency ancillary services in modern power systems

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e-Prime - Advances in Electrical engineering, Electronics and Energy 2024年 9卷

作者： Ullah, Kaleem Ullah, Zahid Basit, Abdul Gruosso, Giambattista US-Pakistan Center for Advanced Studies in Energy University of Engineering and Technology Peshawar Peshawar 25000 Pakistan Dipartimento di Elettronica Informazione e Bioingegneria Politecnico di Milano Piazza Leonardo Da Vinci 32 Milan 20133 Italy Manager R&D National Power Control Center National Transmission and Dispatch Company Islamabad 44000 Pakistan

The widespread global adoption of wind energy sources has established a significant presence in the existing power grid. However, the massive integration of intermittent wind energy poses forecasting errors, prompting the need for supplementary reserves from conventional energy sources with increased operational expenses and carbon emissions. Hence, to facilitate the seamless operation of large-scale wind-integrated power grids, it is imperative to harness the potential of renewable energy sources and leverage flexible loads to deliver power-balancing services. In this research, dynamic real-time power dispatch strategies have been developed for the Automatic Generation Control (AGC) system to integrate the reserve capacities of conventional generation units and wind power plants and utilize the demand response capabilities of flexible loads for power balancing services. A comprehensive power system grid model was developed in digSilent PowerFactory software, consisting of coal-based energy systems, wind energy systems, gas turbines, and cold storage units as flexible loads. The study is divided into different case studies to assess the impact of each scenario on system operation in mitigating the forecasting errors of wind power plants. Further, a comparative analysis was performed to illustrate the effectiveness of each case study. The analysis showed that Case Study III, where reserves are provided by coal energy systems and cold storage units, yielded the highest reduction in Positive regulation (Pr) and Negative regulation (Nr) errors, at 89.0% and 94.15%, respectively. Conversely, Case Study IV demonstrated the least reduction in errors, with 67.82% in Pr and 78.41% in Nr. However, it indicates that reserves can be supplied from wind energy systems and flexible loads without the support of conventional power plants. © 2024 The Author(s)

关键词： and Automatic Generation Control Coal-based Energy Systems Frequency regulation Power dispatch Strategies Wind Energy Systems

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Boosting Monocular 3d Object detection with Object-Centric Auxiliary depth Supervision

arXiv

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arXiv 2022年

作者： Kim, Youngseok Kim, Sanmin Sim, Sangmin Choi, Jun Won Kum, dongsuk The Graduate School of Mobility Korea Advanced Institute of Science and Technology [KAIST Daejeon34141 Korea Republic of The Automotive R&D Division Hyundai Motor Company Seoul06182 Korea Republic of Department of Electrical Engineering Hanyang University Seoul04763 Korea Republic of

recent advances in monocular 3d detection leverage a depth estimation network explicitly as an intermediate stage of the 3d detection network. depth map approaches yield more accurate depth to objects than other methods thanks to the depth estimation network trained on a large-scale dataset. However, depth map approaches can be limited by the accuracy of the depth map, and sequentially using two separated networks for depth estimation and 3d detection significantly increases computation cost and inference time. In this work, we propose a method to boost the rGB image-based 3d detector by jointly training the detection network with a depth prediction loss analogous to the depth estimation task. In this way, our 3d detection network can be supervised by more depth supervision from raw LidAr points, which does not require any human annotation cost, to estimate accurate depth without explicitly predicting the depth map. Our novel object-centric depth prediction loss focuses on depth around foreground objects, which is important for 3d object detection, to leverage pixel-wise depth supervision in an object-centric manner. Our depth regression model is further trained to predict the uncertainty of depth to represent the 3d confidence of objects. To effectively train the 3d detector with raw LidAr points and to enable end-to-end training, we revisit the regression target of 3d objects and design a network architecture. Extensive experiments on KITTI and nuScenes benchmarks show that our method can significantly boost the monocular image-based 3d detector to outperform depth map approaches while maintaining the real-time inference speed. Copyright © 2022, The Authors. All rights reserved.

关键词： Object detection

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