检索结果-南通市图书馆

Petroleum research 2024年第1期9卷 37-47页

作者： Dongsheng Xiao Xiong fei Xu Jilun Kang Yiting Zhang Petrochina Tuha oilfield Company Exploration and Development research institute China

Lucaogou Formation in the Santanghu Basin is a special lacustrine fine-grained sedimentary deposits rich in volcanic debris and carbonate,with abundant shale oil resources.However,understanding of shale oil characteristics and genesis remains unclear.Lithofacies,sedimentary environment,and formation mechanisms of tuffaceous shale oil are investigated based on core and thin section observations,X-ray diffraction,field emission SEM and geochemical analysis.Results show that three mixed lithofacies types are developed in Lucaogou Formation:blocky tuff,laminated tuffaceous dolomite,and laminated dolomitic tuff.These lithofacies types are characterized by high content of felsic and dolostone,widespread organic matter,and low clay content.Formation of tuffaceous shale oil sweet spots is primarily influenced by four factors:inputting of volcanic ash as a high-quality source rocks and reservoirs provides good material basis;devitrification of volcanic glass,calcitization,and dissolution are crucial for formation of reservoirs;expulsion of source rocks with high-abundance organic matter expulsion facilitates migration and accumulation of hydrocarbon in adjacent reservoirs;fracture development improves reservoir permeability to form highly productive sweet spots.By analyzing characteristics and genesis of tuffaceous shale oil,the main controlling factors of reservoir physical property and oil saturation are clarified,which is of great significance for selection of shale oil exploration zones.

关键词： shale oil Tuffaceous Formation mechanism Lucaogou formation Santanghu basin

The Influence of Acid on the RockMechanical Characteristics of Deep Shale in theWujiaping Formation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy Engineering 2024年第1期121卷 27-42页

作者： Hao Zhang Yan Zhang Wei Liu Ximin Zhang Xiang Liu School of Petroleum Engineering Yangtze UniversityWuhan430100China Petroleum Engineering technology research institute Jianghan Oilfield Branch of SinopecWuhan430035China Drilling technology research institute Sinopec Shengli Oilfield Service CorporationDeyang618000China

The microscopic characteristics and mechanical properties of rocks change after the action of acid on deep shale,which affects the fracturing effect.Accordingly,we designed and conducted indoor experiments related to the changes in macro and microscopic characteristics after the interaction of acid with the shale of Wujiaping Formation,based on which the characteristic law of fracture volume modification after acid fracturing was studied using numerical simulation.The results demonstrate that the pores and fractures are enlarged and the structure is significantly loosened after the acid immersion.And a 15%concentration of hydrochloric acid can effectively dissolve shale.Furthermore,the degree of acid-etching reaction is highly variable because of the different carbonate content,which reveals the strong inhomogeneity of the shale system in the Wujiaping Group reservoir section.After the acid interacted with the shale rock samples,the triaxial compressive strength,elastic modulus,and Poisson’s ratio of shale decreased.Moreover,the evaluation of the effect after acid fracturing simulated by fracturing software revealed that the smaller the value of elastic modulus in shale-based reservoirs,the more favorable the fracture volume modification.This discovery not only provides a theoretical basis for the expansion and extension patterns of acid-fracturing in carbonaceous shale formations but also offers research methods and theoretical insights for the fundamental exploration of other deep-seated oil and gas resources.

关键词： Shale acid fracturing macro characteristics microscopic characteristics mechanical properties

Simulation of Two-Phase Flowback Phenomena in Shale Gas wells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2024年第2期20卷 349-364页

作者： Yongwei Duan Zhaopeng Zhu Hui He Gaoliang Xuan Xuemeng Yu Oil Gas Engineering research institute PetroChina Jilin OilfieldSongyuan138000China

The gas-water two-phaseﬂow occurring as a result of fracturingﬂuidﬂowback phenomena is known to impact signiﬁcantly the productivity of shale gas well.In this work,this two-phaseﬂow has been simulated in the framework of a hybrid approach partially relying on the embedded discrete fracture model(EDFM).This model assumes the region outside the stimulated reservoir volume(SRV)as a single-medium while the SRV region itself is described using a double-medium strategy which can account for theﬂuid exchange between the matrix and the micro-fractures.The shale gas adsorption,desorption,diffusion,gas slippage effect,fracture stress sensitivity,and capillary imbibition have been considered.The shale gas production,pore pressure distribution and water saturation distribution in the reservoir have been simulated.The inﬂuences of hydraulic fracture geometry and nonorthogonal hydraulic fractures on gas production have been determined and discussed accordingly.The simulation results show that the daily gas production has an upward and downward trend due to the presence of a large amount of fracturingﬂuid in the reservoir around the hydraulic fracture.The smaller the angle between the hydraulic fracture and the wellbore,the faster the daily production of shale gas wells decreases,and the lower the cumulative production.Nonplanar fractures can increase the control volume of hydraulic fractures and improve the production of shale gas wells.

关键词： Shale gas fracturingﬂuid backﬂow the stimulated reservoir volume gas-water two-phase production

Study of Seismic P Wave in Mesoscale Fracture-Induced Arbitrary Anisotropic Media

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年第2期35卷 717-721页

作者： Han Xiao Xinmin Shang Zhentao Wang Xiping Wang Geophysical research institute SINOPEC Shengli Oilfield CompanyShandong 257022China Working Station for Postdoctoral Scientific research Shengli OilfieldShandong 257000China

Mesoscale fracture controls the permeability of shale res ervoirs,it is one of the main research objectives of natural frac tures.The length of the mesoscale fracture is less than 1/4 of the seismic eigen wavelength and greater than 1%of the seis mic eigen wavelength,they cannot be identified in actual seis mic data and are usually displayed by the azimuthal anisotropy of seismic attributes.In this paper,we propose a calculation process from fracture properties to seismic P-wave velocity and traveltime in anisotropic media induced by multiple sets of arbitrary occurring mesoscale fractures.Based on this process,the variations of the media’s Anisotropic(A-)parameters with fracture properties are studied.Furthermore,variation of P-wave NMO elliptical principle axis with the relative fracture density is studied according to the arbitrary anisotropic theory based on A-parameters.

关键词： seismic mesoscale shale

Implications for fault reactivation and seismicity induced by hydraulic fracturing

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1081-1098页

作者： Zi-Han Sun Ming-Guang Che Li-Hong Zhu Shu-Juan Zhang Ji-Yuan Lu Chang-Yu Jin Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines School of Resources and Civil Engineering and Key Laboratory of Liaoning Province on Deep Engineering and Intelligent TechnologyNortheastern UniversityShenyang110819LiaoningChina research institute of Petroleum Exploration&Development PetroChina Company LimitedBeijing100084China The Exploration and Development research institute of Daqing oilfield limited Company Daqing163458HeilongjiangChina

Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operations. Current understanding supports the overriding role of the effective stress magnitude in triggering earthquakes, while the impact of change rate of effective stress has not been systematically addressed. In this work, a modified critical stiffness was brought up to investigate the likelihood, impact,and mitigation of induced seismicity during and after hydraulic fracturing by developing a poroelastic model based on rate-and-state fraction law and linear stability analysis. In the new criterion, the change rate of effective stress was considered a key variable to explore the evolution of this criterion and hence the likelihood of instability slip of fault. A coupled fluid flow-deformation model was used to represent the entire hydraulic fracturing process in COMSOL Multiphysics. The possibility of triggering an earthquake throughout the entire hydraulic fracturing process, from fracturing to cessation, was investigated considering different fault locations, orientations, and positions along the fault. The competition between the effects of the magnitude and change rate of effective stress was notable at each fracturing stage. The effective stress magnitude is a significant controlling factor during fracturing events, with the change rate dominating when fracturing is suddenly started or stopped. Instability dominates when the magnitude of the effective stress increases(constant injection at each fracturing stage) and the change rate of effective stress decreases(the injection process is suddenly stopped). Fracturing with a high injection rate, a fault adjacent to the hydraulic fracturing location and the position of the junction between the reservoir and fault are important to reduce the Coulomb failure stress(CFS) and enhance the critical stiffness as the significant disturbance of stresses at thes

关键词： Hydraulic fracturing Coulomb failure stress Rate-and-state fraction model Linear stability analysis Critical stiffness Seismically induced fault

Geometry and formation mechanism of tension gashes and their implication on the hydrocarbon accumulation in the deep-seated strata of sedimentary basin:A case from Shunnan area of Tarim Basin

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 87-99页

作者： Yan-Nan Du Kong-You Wu Yin Liu Yan-Ying Li Zi-Cheng Cao You-Wei Cui Jun Liu Key Laboratory of Deep Oil and Gas School of GeosciencesChina University of Petroleum(East China)Qingdao 266580ShandongChina Exploration and Development research institute SINOPEC Northwest Oilfield BranchUrumqi 830011XinjiangChina The Fifth Gas Production Plant Changqing OilfieldPetroChinaXi'an 710018ShaanxiChina

With the theoretical and technological developments related to cratonic strike-slip faults,the Shuntuoguole Low Uplift in the Tarim Basin has attracted considerable attention recently.Affected by multi-stage tectonic movements,the strike-slip faults have controlled the distribution of hydrocarbon resources owing to the special fault characteristics and fault-related structures.In contrast,the kinematics and formation mechanism of strike-slip faults in buried sedimentary basins are difficult to investigate,limiting the discussion of these faults and hydrocarbon accumulation.In this study,we identified the characteristics of massive sigmoidal tension gashes(STGs)that formed in the Shunnan area of the Tarim Basin.High-resolution three-dimensional seismic data and attribute analyses were used to investigate their geometric and kinematic characteristics.Then,the stress state of each point of the STGs was calculated using seismic curvature attributes.Finally,the formation mechanism of the STGs and their roles in controlling hydrocarbon migration and accumulation were discussed.The results suggest that:(1)the STGs developed in the Shunnan area have a wide distribution,with a tensile fault arranged in an enéchelon pattern,showing an S-shaped bending.These STGs formed in multiple stages,and differential rotation occurred along the direction of strike-slip stress during formation.(2)Near the principal displacement zone of the strike-slip faults,the stress value of the STGs was higher,gradually decreasing at both ends.The shallow layer deformation was greater than the deep layer deformation.(3)STGs are critical for connecting source rocks,migrating oil and gas,sealing horizontally,and developing efficient reservoirs.This study not only provides seismic evidence for the formation and evolution of super large STGs,but also provides certain guidance for oil and gas exploration in this area.

关键词： Tarim Basin Sigmoidal tension gashes Seismic attributes Shear stress calculation Formation mechanism Reservoir control

Dynamic interwell connectivity analysis of multi-layer waterflooding reservoirs based on an improved graph neural network

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1062-1080页

作者： Zhao-Qin Huang Zhao-Xu Wang Hui-Fang Hu Shi-Ming Zhang Yong-Xing Liang Qi Guo Jun Yao School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Exploration and Development research institute Shengli OilfieldSINOPECDongying257015ShandongChina

The analysis of interwell connectivity plays an important role in the formulation of oilfield development plans and the description of residual oil distribution. In fact, sandstone reservoirs in china's onshore oilfields generally have the characteristics of thin and many layers, so multi-layer joint production is usually adopted. It remains a challenge to ensure the accuracy of splitting and dynamic connectivity in each layer of the injection-production wells with limited field data. The three-dimensional well pattern of multi-layer reservoir and the relationship between injection-production wells can be equivalent to a directional heterogeneous graph. In this paper, an improved graph neural network is proposed to construct an interacting process mimics the real interwell flow regularity. In detail, this method is used to split injection and production rates by combining permeability, porosity and effective thickness, and to invert the dynamic connectivity in each layer of the injection-production wells by attention mechanism.Based on the material balance and physical information, the overall connectivity from the injection wells,through the water injection layers to the production layers and the output of final production wells is established. Meanwhile, the change of well pattern caused by perforation, plugging and switching of wells at different times is achieved by updated graph structure in spatial and temporal ways. The effectiveness of the method is verified by a combination of reservoir numerical simulation examples and field example. The method corresponds to the actual situation of the reservoir, has wide adaptability and low cost, has good practical value, and provides a reference for adjusting the injection-production relationship of the reservoir and the development of the remaining oil.

关键词： Graph neural network Dynamic interwell connectivity Production-injection splitting Attention mechanism Multi-layer reservoir

Simulation study on cuttings transport of the backreaming operation for long horizontal section wells

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1149-1170页

作者： Yu-Fei Chen Hui Zhang Wen-Xin Wu Jun Li Yong Ouyang Zong-Yu Lu De-Xin Ma Yong-Chuan Wu Jun-Bo Liu Ke-Rou Liu Zhuo-Xin Dong china University of Petroleum(Beijing) Beijing102249China Beijing Normal University at Zhuhai Experimental and Practical Education Innovation CenterZhuhai519087GuangdongChina Oil&Gas technology research institute of Petrochina Changqing oilfield Company Xi©an710016ShaanxiChina Petrochina Xinjiang oilfield Company Karamay834002XinjiangChina china oilfield services Ltd. Tianjin300459China

The backreaming operation plays a significant role in safe drilling for horizontal wellbores, while it may cause severe stuck pipe accidents. To lower the risk of the stuck pipe in backreaming operations, the mechanism of cuttings transport needs to be carefully investigated. In this research, a transient cuttings transport with multiple flow patterns model is developed to predict the evolution of cuttings transported in the annulus while backreaming. The established model can provide predictions of the distribution of cuttings bed along the wellbore considering the bulldozer effect caused by large-size drilling tools(LSDTs). The sensitivity analyses of the size of LSDTs, and backreaming operating parameters are conducted in Section 4. And a new theory is proposed to explain the mechanism of cuttings transport in the backreaming operation, in which both the bit and LSDTs have the “cleaning effect” and “plugging effect”.The results demonstrate that the cuttings bed in annuli is in a state of dynamic equilibrium, but the overall trend and the distribution pattern are obvious. First, larger diameters and longer drilling tools could lead to a higher risk of the stuck pipe. Second, we find that it is not the case that the higher flow rate is always better for hole cleaning, so three flow-rate intervals are discussed separately under the given conditions. When the “dangerous flow rate”(35 L/s in Case 4),the higher the flow rate, the better the cleaning effect of cuttings beds. Third, an interval of tripping velocity called “dangerous velocity” is proposed, in which the cuttings bed accumulation near the LSDTs is more serious than those of other tripping velocities. As long as

关键词： Backreaming Stuck pipe Hole cleaning Transient solid transport Multiple flow patterns

Acid-rock reaction kinetics in a two-scale model based on reaction order correction

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 2089-2101页

作者： Xue-Song Li Ning Qi Ze-Hui Zhang Lian Liu Xia-Qing Li Xu-Hang Su School of Petroleum Engineering China University of Petroleum(East China) Key Lab of Unconventional Oil & Gas Development Ministry of Education China University of Petroleum(East China) SINOPEC Northwest oilfield Branch Company Petroleum Engineering technology research institute SINOPEC Shengli Oilfield Company

The reaction order plays a crucial role in evaluating the response rate of acid-rock. However, the conventional two-scale model typically assumes that the reaction order is constant as one, which can lead to significant deviations from reality. To address this issue, this study proposes a novel multi-order dynamic model for acid-rock reaction by combining rotating disk experimental data with theoretical derivation.Through numerical simulations, this model allows for the investigation of the impact of acidification conditions on different orders of reaction, thereby providing valuable insights for on-site construction.The analysis reveals that higher response orders require higher optimal acid liquid flow rates, and lower optimal H+diffusion coefficients, and demonstrate no significant correlation with acid concentration.Consequently, it is recommended to increase the displacement and use high-viscosity acid for reservoirs with high calcite content, while reducing the displacement and using low-viscosity acid for reservoirs with high dolomite content.

关键词： Reaction order Two-scale model Wormhole propagation Carbonate rocks Numerical simulation

research on Quantitative Identification of Three-Dimensional Connectivity of Fractured-Vuggy Reservoirs

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Energy Engineering 2024年第5期121卷 1195-1207页

作者： Xingliang Deng Peng Cao Yintao Zhang Yuhui Zhou Xiao Luo Liang Wang Exploration and Development research institute PetroChina Tarim Oilfield CompanyKorla841000China Petrochina Hangzhou research institute of Geology Hangzhou310023China School of Petroleum Engineering Yangtze UniversityWuhan430100China

The fractured-vuggy carbonate oil resources in the western basin of china are extremely rich.The connectivity of carbonate reservoirs is complex,and there is still a lack of clear understanding of the development and topological structure of the pore space in fractured-vuggy reservoirs.Thus,effective prediction of fractured-vuggy reservoirs is difficult.In view of this,this work employs adaptive point cloud technology to reproduce the shape and capture the characteristics of a fractured-vuggy reservoir.To identify the complex connectivity among pores,fractures,and vugs,a simplified one-dimensional connectivity model is established by using the meshless connection element method(CEM).Considering that different types of connection units have different flow characteristics,a sequential coupling calculation method that can efficiently calculate reservoir pressure and saturation is developed.By automatic history matching,the dynamic production data is fitted in real-time,and the characteristic parameters of the connection unit are inverted.Simulation results show that the three-dimensional connectivity model of the fractured-vuggy reservoir built in this work is as close as 90%of the fine grid model,while the dynamic simulation efficiency is much higher with good accuracy.

关键词： Fractured-vuggy reservoir three-dimensional connectivity connection unit dynamic prediction automatic history matching