Faults and fractures of multiple scales are frequently induced and generated in compressional structural system. Comprehensive identification of these potential faults and fractures that cannot be distinguished direct...Faults and fractures of multiple scales are frequently induced and generated in compressional structural system. Comprehensive identification of these potential faults and fractures that cannot be distinguished directly from seismic profile of the complex structures is still an unanswered problem. Based on the compressional structural geometry and kinematics theories as well as the structural interpretation from seismic data, a set of techniques is established for the identification of potential faults and fractures in compressional structures. Firstly, three-dimensional(3D) patterns and characteristics of the faults directly interpreted from seismic profile were illustrated by 3D structural model. Then, the unfolding index maps, the principal structural curvature maps, and tectonic stress field maps were obtained from structural restoration. Moreover, potential faults and fractures in compressional structures were quantitatively identified relying on comprehensive analysis of these three maps. Successful identification of the potential faults and fractures in Mishrif limestone formation and in Asmari dolomite formation of Buzurgan anticline in Iraq demonstrates the applicability and reliability of these techniques.展开更多
A fault is not simply a plane, but a zone consisting of a series of broken planes or lower faults. The greater the scale of faults, the wider and more complex the fault zone is. Fault-sealing properties are influenced...A fault is not simply a plane, but a zone consisting of a series of broken planes or lower faults. The greater the scale of faults, the wider and more complex the fault zone is. Fault-sealing properties are influenced by the fault zone itself, whose fault displacement, depth, net-to-gross-ratio of mudstone, fault plane angle, and fault mechanical properties play important controlling roles. The sealing of hydrocarbon by the fault zone depends on whether the fault zone can form a continuous sealing zone and if the pore throats connecting those fault zones are small enough. The concept of fault zone-sealing potential is proposed here, and a quantitative formula is established by using a great amount of practical statistical data as well as the fuzzy comprehensive evaluation method, which is a comprehensive characterization parameter to judge whether or not fault zones could seal oil hydrocarbon. The greater the value of the fault zone-sealing potential, the better sealed the fault is. For example, with increasing depth, the sealing degree of the Xin 68 Fault in the Dongxin 1 oilfield changes greatly, reflecting the complexity of fault-sealing properties.展开更多
This study numerically investigates the thermo-poromechanical effects in a Canadian geothermal reservoir caused by long-term fluid production and injection.Using finite element modeling,it explores pore pressure diffu...This study numerically investigates the thermo-poromechanical effects in a Canadian geothermal reservoir caused by long-term fluid production and injection.Using finite element modeling,it explores pore pressure diffusion and thermal dynamics,incorporating both the geological structure of the rock mass and faults.The simulations utilize the IAPWS(International Association for the Properties of Water and Steam)equations to model fluid density and viscosity,ensuring realistic representations of heterogeneous pressure fields.The system replicates a doublet configuration within a faulted zone,featuring two hydraulically stimulated fractures.The primary aim is to assess the likelihood of fault reactivation under varying in-situ stress conditions over a 100-year geothermal operation.Results show that stress distribution is largely influenced by thermal stresses along the fluid circulation pathway,with fluid velocity and temperature gradients affecting reservoir stability.Minimal pore pressure changes highlight the dominant role of thermal stresses in controlling fault behavior.The analysis indicates no potential for fault reactivation,as slip tendency values remain below the critical threshold,even when accounting for reduced mechanical properties using the Hoek-Brown criterion.Thermal effects continue to influence the surrounding rock throughout the operational period,suggesting that the reservoir maintains mechanical stability conducive to sustained geothermal production and injection.These findings provide valuable insights into the long-term safety and behavior of geothermal reservoirs,offering important implications for future geothermal energy development and management strategies.展开更多
基金Project(2014CB239205)supported by the National Basic Research Program of ChinaProject(20011ZX05030-005-003)supported by the National Science and Technology Major Project of China
文摘Faults and fractures of multiple scales are frequently induced and generated in compressional structural system. Comprehensive identification of these potential faults and fractures that cannot be distinguished directly from seismic profile of the complex structures is still an unanswered problem. Based on the compressional structural geometry and kinematics theories as well as the structural interpretation from seismic data, a set of techniques is established for the identification of potential faults and fractures in compressional structures. Firstly, three-dimensional(3D) patterns and characteristics of the faults directly interpreted from seismic profile were illustrated by 3D structural model. Then, the unfolding index maps, the principal structural curvature maps, and tectonic stress field maps were obtained from structural restoration. Moreover, potential faults and fractures in compressional structures were quantitatively identified relying on comprehensive analysis of these three maps. Successful identification of the potential faults and fractures in Mishrif limestone formation and in Asmari dolomite formation of Buzurgan anticline in Iraq demonstrates the applicability and reliability of these techniques.
基金the project "Study on Technology to Increase the Recovery Ratio in Oilfields with Complex Fault Block" (P01035), a Science and Technology Promotion Project in the Tenth Five-Year Plan of SINOPECT
文摘A fault is not simply a plane, but a zone consisting of a series of broken planes or lower faults. The greater the scale of faults, the wider and more complex the fault zone is. Fault-sealing properties are influenced by the fault zone itself, whose fault displacement, depth, net-to-gross-ratio of mudstone, fault plane angle, and fault mechanical properties play important controlling roles. The sealing of hydrocarbon by the fault zone depends on whether the fault zone can form a continuous sealing zone and if the pore throats connecting those fault zones are small enough. The concept of fault zone-sealing potential is proposed here, and a quantitative formula is established by using a great amount of practical statistical data as well as the fuzzy comprehensive evaluation method, which is a comprehensive characterization parameter to judge whether or not fault zones could seal oil hydrocarbon. The greater the value of the fault zone-sealing potential, the better sealed the fault is. For example, with increasing depth, the sealing degree of the Xin 68 Fault in the Dongxin 1 oilfield changes greatly, reflecting the complexity of fault-sealing properties.
基金the Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery Grant Canada(NO.RGPIN-2024-05104).
文摘This study numerically investigates the thermo-poromechanical effects in a Canadian geothermal reservoir caused by long-term fluid production and injection.Using finite element modeling,it explores pore pressure diffusion and thermal dynamics,incorporating both the geological structure of the rock mass and faults.The simulations utilize the IAPWS(International Association for the Properties of Water and Steam)equations to model fluid density and viscosity,ensuring realistic representations of heterogeneous pressure fields.The system replicates a doublet configuration within a faulted zone,featuring two hydraulically stimulated fractures.The primary aim is to assess the likelihood of fault reactivation under varying in-situ stress conditions over a 100-year geothermal operation.Results show that stress distribution is largely influenced by thermal stresses along the fluid circulation pathway,with fluid velocity and temperature gradients affecting reservoir stability.Minimal pore pressure changes highlight the dominant role of thermal stresses in controlling fault behavior.The analysis indicates no potential for fault reactivation,as slip tendency values remain below the critical threshold,even when accounting for reduced mechanical properties using the Hoek-Brown criterion.Thermal effects continue to influence the surrounding rock throughout the operational period,suggesting that the reservoir maintains mechanical stability conducive to sustained geothermal production and injection.These findings provide valuable insights into the long-term safety and behavior of geothermal reservoirs,offering important implications for future geothermal energy development and management strategies.
