Based on seismic and drilling data,the reactivation mechanism of the pre-existing basement F4 strike-slip faultin Nanpu sag and its controlling effect on hydrocarbon accumulation difference are systematically studied....Based on seismic and drilling data,the reactivation mechanism of the pre-existing basement F4 strike-slip faultin Nanpu sag and its controlling effect on hydrocarbon accumulation difference are systematically studied.By defining fault activation stages,back-stripping fault throw and physical modeling,it is found that the Nanpu No.4 structural zone formed by the Cenozoic reactivity of the F4 fault grew from south to north,with strike-slip deformation dominated in the south and extensional deformation dominated in the north.Faults in the No.4 structural zone and those in the adjacent No.2 and No.3 structural zones were different fault systems,which grew separately,contacted and connected,and finally interwove under the action of unified stress field.By constructing the identification chart of deformation mechanisms of reactivation of pre-existing faults,it is concluded that during the sedimentary period of the Paleogene Shahejie Formation,F4 fault was reactivated by strike-slip faulting,and during the sedimentary period of Paleogene Dongying Formation and Neogene Guantao-Minghuazhen formations,it was reactivated by oblique extension.The controlling effects of Cenozoic reactivation of F4 fault on hydrocarbon accumulation include:(1)As the oil-source fault,it controlled the vertical cross-layer migration of oil and gas.(2)It gave rise to strike-slip transfer zone to control the distribution of sand bodies.(3)It grew upward and interacted with faults in the neighboring area,controlling the formation of two types of traps,and was favorable for oil and gas accumulation.展开更多
Based on previous studies on the internal structures of fault belts, the fault belts in the Laoyemiao Oilfield of the Nanpu Sag can be divided into three units, a crushed zone, an upper induced fracture zone and a low...Based on previous studies on the internal structures of fault belts, the fault belts in the Laoyemiao Oilfield of the Nanpu Sag can be divided into three units, a crushed zone, an upper induced fracture zone and a lower induced fracture zone according to the log response characteristics. The upper induced fracture zone is characterized by the development of pervasive fractures and has a poor sealing or non-sealing capability. It therefore can act as pathways for hydrocarbon migration. The lower induced fracture zone consists of fewer fractures and has limited sealing capability. The crushed zone has a good sealing capability comparable to mudstone and can thus prevent lateral migration of fluid. Through physical modeling and comparing laboratory data with calculated data of oil column heights of traps sealed by faults, it is concluded that the fault-sealing capability for oil and gas is limited. When the oil column height reaches a threshold, oil will spill over from the top of reservoir along the lower induced fracture zone under the action of buoyancy, and the size of reservoir will remain unchanged. Analysis of the formation mechanisms of the fault-sealed reservoirs in the Nanpu Sag indicated that the charging sequence of oil and gas in the reservoir was from lower formation to upper formation, with the fault playing an important role in oil and gas accumulation. The hydrocarbon potential in reverse fault-sealed traps is much better than that in the consequent fault-sealed traps. The reverse fault-sealed traps are favorable and preferred exploration targets.展开更多
The Nanpu（南堡） sag has previously been modeled as（1） a pull-apart basin,（2） a rift ba-sin,without significant strike-slip deformation,and（3） a transtensional basin.We present a new model for the Nanpu sag in ...The Nanpu（南堡） sag has previously been modeled as（1） a pull-apart basin,（2） a rift ba-sin,without significant strike-slip deformation,and（3） a transtensional basin.We present a new model for the Nanpu sag in which the basin is a transtensional fault-termination basin.Although transten-sional fault-termination basins is an important basin type,it is not as well studied as other classic basin types.On the base of 3D seismic data interpretation,the faults geometries and kinematics and their controls on depocenters are presented.The Nanpu sag is developed in the context of dextral transten-sion of the Bohai（渤海） Bay basin and attributed to a transtensional fault-termination basin.During deposition of the Es3-Es2 members,the basin border Xi＇nanzhuang（西南庄） fault and Baigezhuang（柏各庄） fault linked to a mixed normal and strike-slip fault system,or a linked fault system controlled the basin by dominant extension and weak strike-slip and created fan-shaped depocenters surrounded by the two faults.From Es1 Member to Dongying（东营） Formation,two major depocenters controlled by two mixed normal and sinistral strike-slip fault systems are located on the Linque（林雀） and Caofeidian（曹妃甸） subsags.During deposition of the Guantao（馆陶）-Minghuazhen（明化镇） Forma-tion,the Nanpu sag successively developed and significantly expanded.展开更多
To evaluate the lateral sealing mechanism of extensional fault based on the pressure difference between fault and reservoir, an integral mathematical-geological model of diagenetic time on diagenetic pressure consider...To evaluate the lateral sealing mechanism of extensional fault based on the pressure difference between fault and reservoir, an integral mathematical-geological model of diagenetic time on diagenetic pressure considering the influence of diagenetic time on the diagenetic pressure and diagenetic degree of fault rock has been established to quantitatively calculate the lateral sealing ability of extensional fault. By calculating the time integral of the vertical stress and horizontal in-situ stress on the fault rock and surrounding rock, the burial depth of the surrounding rock with the same clay content and diagenesis degree as the target fault rock was worked out. In combination with the statistical correlation of clay content, burial depth and displacement pressure of rock in the study area, the displacement pressure of target fault rock was calculated quantitatively. The calculated displacement pressure was compared with that of the target reservoir to quantitatively evaluate lateral sealing state and ability of the extensional fault. The method presented in this work was used to evaluate the sealing of F_(1), F_(2) and F_(3) faults in No.1 structure of Nanpu Sag, and the results were compared with those from fault-reservoir displacement pressure differential methods without considering the diagenetic time and simple considering the diagenetic time. It is found that the results calculated by the integral mathematical-geological model are the closest to the actual underground situation, the errors between the hydrocarbon column height predicted by this method and the actual column height were 0–8 m only, proving that this model is more feasible and credible.展开更多
Crossing conjugate normal faults(CCNFs)are extensively developed in many hydrocarbon-producing basins,generally existing in the form of incomplete CCNFs.Nevertheless,the effect of the non-conjugate zone of the CCNFs o...Crossing conjugate normal faults(CCNFs)are extensively developed in many hydrocarbon-producing basins,generally existing in the form of incomplete CCNFs.Nevertheless,the effect of the non-conjugate zone of the CCNFs on the conjugate relay zone post late tectonic action has not been previously studied.We use 3D elastic-plastic modeling to investigate the influence of incomplete(i.e.,partially intersecting)CCNFs on the pattern of deformation of strata in the intersection region.A series of model simulations were performed to examine the effects of horizontal tectonic extension,fault size,and fault depth on the deformation of conjugate relay zones of incomplete CCNFs.Our analyses yielded the following results.(1)The model of incomplete conjugation predicts a convex-up style of deformation in the conjugate graben region superimposed on overall subsidence under applied horizontal tectonic extension.(2)The degree of convex-up deformation of the conjugate graben depends on the influence of the non-conjugate zone on the conjugate relay zone,which varies with the amount of horizontal tectonic extension,fault size,and fault burial depth.(3)Our results indicate that incomplete CCNFs can form convex-up deformation,similar to that in the Nanpu Sag area and provide a sound understanding of hydrocarbon migration and accumulation.展开更多
基金Supported by the Heilongjiang Outstanding Young Talents Support Project(140119002)Research Project of PetroChina Science and Technology Innovation Fund(2020D-5007-0108)PetroChina"14th Five-Year Plan"Science and Technology Project(2021DJ0701).
文摘Based on seismic and drilling data,the reactivation mechanism of the pre-existing basement F4 strike-slip faultin Nanpu sag and its controlling effect on hydrocarbon accumulation difference are systematically studied.By defining fault activation stages,back-stripping fault throw and physical modeling,it is found that the Nanpu No.4 structural zone formed by the Cenozoic reactivity of the F4 fault grew from south to north,with strike-slip deformation dominated in the south and extensional deformation dominated in the north.Faults in the No.4 structural zone and those in the adjacent No.2 and No.3 structural zones were different fault systems,which grew separately,contacted and connected,and finally interwove under the action of unified stress field.By constructing the identification chart of deformation mechanisms of reactivation of pre-existing faults,it is concluded that during the sedimentary period of the Paleogene Shahejie Formation,F4 fault was reactivated by strike-slip faulting,and during the sedimentary period of Paleogene Dongying Formation and Neogene Guantao-Minghuazhen formations,it was reactivated by oblique extension.The controlling effects of Cenozoic reactivation of F4 fault on hydrocarbon accumulation include:(1)As the oil-source fault,it controlled the vertical cross-layer migration of oil and gas.(2)It gave rise to strike-slip transfer zone to control the distribution of sand bodies.(3)It grew upward and interacted with faults in the neighboring area,controlling the formation of two types of traps,and was favorable for oil and gas accumulation.
基金the Key Project of Chinese National Programs for Fundamental Research and Development (973 Program, No. 2006CB202308)the National Natural Science Foundation of China (Grant No. 40472078)
文摘Based on previous studies on the internal structures of fault belts, the fault belts in the Laoyemiao Oilfield of the Nanpu Sag can be divided into three units, a crushed zone, an upper induced fracture zone and a lower induced fracture zone according to the log response characteristics. The upper induced fracture zone is characterized by the development of pervasive fractures and has a poor sealing or non-sealing capability. It therefore can act as pathways for hydrocarbon migration. The lower induced fracture zone consists of fewer fractures and has limited sealing capability. The crushed zone has a good sealing capability comparable to mudstone and can thus prevent lateral migration of fluid. Through physical modeling and comparing laboratory data with calculated data of oil column heights of traps sealed by faults, it is concluded that the fault-sealing capability for oil and gas is limited. When the oil column height reaches a threshold, oil will spill over from the top of reservoir along the lower induced fracture zone under the action of buoyancy, and the size of reservoir will remain unchanged. Analysis of the formation mechanisms of the fault-sealed reservoirs in the Nanpu Sag indicated that the charging sequence of oil and gas in the reservoir was from lower formation to upper formation, with the fault playing an important role in oil and gas accumulation. The hydrocarbon potential in reverse fault-sealed traps is much better than that in the consequent fault-sealed traps. The reverse fault-sealed traps are favorable and preferred exploration targets.
基金supported by the National Natural Science Foundation of China (No. 40402014)
文摘The Nanpu（南堡） sag has previously been modeled as（1） a pull-apart basin,（2） a rift ba-sin,without significant strike-slip deformation,and（3） a transtensional basin.We present a new model for the Nanpu sag in which the basin is a transtensional fault-termination basin.Although transten-sional fault-termination basins is an important basin type,it is not as well studied as other classic basin types.On the base of 3D seismic data interpretation,the faults geometries and kinematics and their controls on depocenters are presented.The Nanpu sag is developed in the context of dextral transten-sion of the Bohai（渤海） Bay basin and attributed to a transtensional fault-termination basin.During deposition of the Es3-Es2 members,the basin border Xi＇nanzhuang（西南庄） fault and Baigezhuang（柏各庄） fault linked to a mixed normal and strike-slip fault system,or a linked fault system controlled the basin by dominant extension and weak strike-slip and created fan-shaped depocenters surrounded by the two faults.From Es1 Member to Dongying（东营） Formation,two major depocenters controlled by two mixed normal and sinistral strike-slip fault systems are located on the Linque（林雀） and Caofeidian（曹妃甸） subsags.During deposition of the Guantao（馆陶）-Minghuazhen（明化镇） Forma-tion,the Nanpu sag successively developed and significantly expanded.
基金Supported by the China National Science and Technology Major Project(41872153)Northeast Petroleum University Research Startup Fund(1305021839)。
文摘To evaluate the lateral sealing mechanism of extensional fault based on the pressure difference between fault and reservoir, an integral mathematical-geological model of diagenetic time on diagenetic pressure considering the influence of diagenetic time on the diagenetic pressure and diagenetic degree of fault rock has been established to quantitatively calculate the lateral sealing ability of extensional fault. By calculating the time integral of the vertical stress and horizontal in-situ stress on the fault rock and surrounding rock, the burial depth of the surrounding rock with the same clay content and diagenesis degree as the target fault rock was worked out. In combination with the statistical correlation of clay content, burial depth and displacement pressure of rock in the study area, the displacement pressure of target fault rock was calculated quantitatively. The calculated displacement pressure was compared with that of the target reservoir to quantitatively evaluate lateral sealing state and ability of the extensional fault. The method presented in this work was used to evaluate the sealing of F_(1), F_(2) and F_(3) faults in No.1 structure of Nanpu Sag, and the results were compared with those from fault-reservoir displacement pressure differential methods without considering the diagenetic time and simple considering the diagenetic time. It is found that the results calculated by the integral mathematical-geological model are the closest to the actual underground situation, the errors between the hydrocarbon column height predicted by this method and the actual column height were 0–8 m only, proving that this model is more feasible and credible.
基金supported by the National Key Research and Development Program of China(No.2022YFF0800703)the National Natural Science Foundation of China(No.42230309).
文摘Crossing conjugate normal faults(CCNFs)are extensively developed in many hydrocarbon-producing basins,generally existing in the form of incomplete CCNFs.Nevertheless,the effect of the non-conjugate zone of the CCNFs on the conjugate relay zone post late tectonic action has not been previously studied.We use 3D elastic-plastic modeling to investigate the influence of incomplete(i.e.,partially intersecting)CCNFs on the pattern of deformation of strata in the intersection region.A series of model simulations were performed to examine the effects of horizontal tectonic extension,fault size,and fault depth on the deformation of conjugate relay zones of incomplete CCNFs.Our analyses yielded the following results.(1)The model of incomplete conjugation predicts a convex-up style of deformation in the conjugate graben region superimposed on overall subsidence under applied horizontal tectonic extension.(2)The degree of convex-up deformation of the conjugate graben depends on the influence of the non-conjugate zone on the conjugate relay zone,which varies with the amount of horizontal tectonic extension,fault size,and fault burial depth.(3)Our results indicate that incomplete CCNFs can form convex-up deformation,similar to that in the Nanpu Sag area and provide a sound understanding of hydrocarbon migration and accumulation.
