The time-frequency electromagnetic （TFEM） method combines frequency-domain sounding with time-domain sounding to form a comprehensive system so that it is possible to select different frequencies and induce waves ac...The time-frequency electromagnetic （TFEM） method combines frequency-domain sounding with time-domain sounding to form a comprehensive system so that it is possible to select different frequencies and induce waves according to the objective depth to be explored. During processing not only resistivity but also polarization information can be provided so we can study resistivity as well as predict oil-bearing characteristics simultaneously. Timedomain resistivity information is obtained by pseudo-2D resistivity inversion and frequencydomain IP information is obtained using the Cole-Cole model. Some successful applications in western China show that it provides unique results in an overthrust zone, deep igneous rock investigation, and hydrocarbon prediction.展开更多
There are some differences in reservoir quality of clastic rock between the hanging wall and the foot wall of the Ke-Bai overthrust belt, northwestern margin of the Junggar Basin, western China, which affect the effic...There are some differences in reservoir quality of clastic rock between the hanging wall and the foot wall of the Ke-Bai overthrust belt, northwestern margin of the Junggar Basin, western China, which affect the efficient petroleum exploration in this highly mature exploration area. Based on a large number of thin-sections, cast thin-sections, and physical property analysis of cores, we systematically discuss the Permian-Jurassic reservoir differences between the hanging wall and the foot wall of the Ke- Bai overthrust fault from the aspects of structural evolution, time-space distribution of the depositional system, diagenesis characteristics, and reservoir quality and analyzed the reasons for the differences in reservoir properties. The overthrusting of the Ke-Bai fault directly results in different burial histories, diagenesis evolution, and porosity evolution between the hanging wall and the foot wall. The diflbrences of reservoir characteristics are mainly embodied in buried depth, grain size, sedimentary facies, diagenetic stage, and reservoir quality. The analysis results showed that burial history and depositional characteristics controlled by overthrusting are direct influencing factors of reservoir differences. Because of shallow burial depth of the hanging wall, the reservoir compaction is weak and primary pores are preserved well. The porosity of reservoir on the hanging wall is generally 10%-25%. The strata on the foot wall are deeply buried, and there are mainly mixed pores with the average porosity of 5%-20%. The favorable reservoir on the foot wall is generally developed near faults or in the channel sand bodies, which are usually dissolution development areas.展开更多
On the basis of interpretation of comprehensive geophysical data and foreign data analysis,there existed a lot of overburden detachment shear thrust faults along the southeastern margin of Nansha Trough,which composed...On the basis of interpretation of comprehensive geophysical data and foreign data analysis,there existed a lot of overburden detachment shear thrust faults along the southeastern margin of Nansha Trough,which composed imbricated overthrust nappe structure.Thrust-faulted nappe structure pattern is determined in this area,which consists of frontal fault zone,thrust fault-folded zone and root zone structures,and presents regularly zonation on plane.The detail description of the structural geometrical characteristics is given in shallow thrust fault zone,and the kinematical mechanism of thrust fault nappe structure is furtherly discussed.Overthrnst nappe structure in this area is resulted from island arc-continent collision and orogenic activities.展开更多
The region around the Karamay-Baikouquan （Ke-Bai） overthrust belt is the richest in hydrocarbon accumulation in the Junggar Basin. Previous research has indicated that oil in the region came from the Fengcheng Forma...The region around the Karamay-Baikouquan （Ke-Bai） overthrust belt is the richest in hydrocarbon accumulation in the Junggar Basin. Previous research has indicated that oil in the region came from the Fengcheng Formation in the Mahu Depression to the northeast of the region, but the oil distribution around the Mahu Depression is remarkably uneven. Large amounts of oil have been found in the Ke-Bai overthrust belt to the west of the depression and only some small oilfields have been discovered in the eastern margin of the depression. This uneven distribution revealed that the oil source of the Ke- Bai region might not be from the Mahu Depression. The oil type distribution and the oil migration pattern revealed in this paper showed that there may be another oil source under the Karamay overthrust. Based on geochemical data, the oil was classified into two types from the sterane and terpane characteristics. Type A oil was mainly distributed in the Huwan area and blocks V and VIII of the Karamay Oilfield in the southern part of the region, while type B oil was mainly distributed in the Baikouquan Oilfield in the northern part of the region. In addition, oil migration pathways and direction were determined by the values of diasterane / regular sterane and C30 moretane / C30 hopane ratios. It is shown that the oil of Huwan area on the hanging wall of the overthrust was mainly charged along the overthrust fault surfaces and then migrated to the west, whereas the oil in blocks V and VIII on the foot wall of the overthrust came from the Mahu Depression in the east. As a result, there may be at least two hydrocarbon source kitchens in the study area. The hydrocarbons in the blocks V and VIII on the footwall of the overthrust belt and in the Baikouquan Oilfield mainly came from the Fengcheng Formation in the Mahu Depression, and the hydrocarbons in the Huwan area on the hanging wall of the overthrust belt may come from another hydrocarbon source kitchen below the overthrust. This recognition indicates that there is substantial exploration potential in the deep Carboniferous strata on the hanging wall of the overthrust belt.展开更多
The arcuate nappe structure on the north edge of the Wuliang Mountains in westernYunnan Province is a complex nappe structural system with multiple superimposed structures.The autochthonous system is a WNW-trending ar...The arcuate nappe structure on the north edge of the Wuliang Mountains in westernYunnan Province is a complex nappe structural system with multiple superimposed structures.The autochthonous system is a WNW-trending arcuate fold belt consisting of the Jurassic andCretaceous and the allochthonous system is mainly composed of Upper Triassic rocks. Generally,the nappe structure moved from south to north, with the hanging wall thrusting in a WNW direc-tion for a distance of over 10km. The deep nappe structural system was formed at depths ofabout 5-10km in an environment not exceeding the greenschist facies. It occurred in theOligocene (about 40-20 Ma).展开更多
The external thrustbelt of Albania consists of some tectonic zones(Ionian,Kruja and Krasta-Cukali zones),that are westward overthrust,with a large amplitude(50e100 km),above the Apulian platform and South Adriatic Bas...The external thrustbelt of Albania consists of some tectonic zones(Ionian,Kruja and Krasta-Cukali zones),that are westward overthrust,with a large amplitude(50e100 km),above the Apulian platform and South Adriatic Basin.The relative movement of the Adriatico-Apulian sub-plate between,the Euro Asiatic and African plates during from the Mesozoic to the Tertiary period,mainly controlled the tectonic evolution of the Albanides.The Ionian zone consists of anticline belts(Berati,Kurveleshi and Cika),that are overthrust toward the west with an amplitude about 20e30 km Their overthrustings was realized through regional sliding evaporitic horizons,which caused the masking of folded structures in the subthrust,with the perspective plays.The Kurveleshi anticlinal belt represents a mega-anticlinal with a length of 210 km and a width of about 20 km,and it is characterized by anticline structures with heterogeneous dimensions,predominantly those of great dimensions and linear type.The overthrusting of the anticline units has a local character,and it is more developed in the Kurveleshi anticlinal belt.Its magnitude is about 8e10 km.As a result of these overthrusts,imbrication and duplex styles are formed,leadind to the masking of the subthrust complex with structures of large interest(e.g.Delvina,Karbunara,etc.)where two oil fields have been dioscovered beneath the Mali Gjere anticline(Delvina oil field)and the Kremenara anticline(Karbunara oil field).Backthrust faults phenomena are secondary and they taken place in the post-collision stage.Generally they are easterward thrust faults of structural units with an amplitude of 5e10 km.The Kurveleshi anticlinal belt,based on tectonic features,is divided into two parts:The southern part,from Qafa Sevaster in the north down to Greece to the south.and northern part,from Qafa Sevaster in the south up to the end of the Patos-Verbas structure.In the southern part these features predominate:The anticline structures are large in size,and overthrust with a large amplitude(8e10 km)westward.The evaporitic diapirs have erupted through local faults of the anticline structures of the Kurveleshi anticlinal belt(Mali Gjere,Kurveleshi and Fterra anticlines).These eruptions(Delvina,Picar-Kapariel-Bashaj,etc.)have helped in the overthrusting of these structural units.It must be mentioned that the backthrusting is also affected by the diapir action.Moreover,vertical diapir occur,in the center of the structures like Navarica.In the northern part,the anticline structures are generally small to medium in size.Only the Patos-Verbas anticline is larger in size.In the Kurveleshi anticlinal belt the Ballsh and Visoka oilfields have developed.The eastern flank of the Shushica synclinal belt apears folded,and the carbonate anticline structures have developed.Existing oil fields include the Gorisht-Kocul,Cakran-Moallaj-Kreshpan and Amonica.These oil fields shoud continue towards the north(under the overthrust of the Patos-Verbas antcline)and in the south(under the regional ovethrust of the Kuervelesh anticlinal belt).展开更多
文摘The time-frequency electromagnetic （TFEM） method combines frequency-domain sounding with time-domain sounding to form a comprehensive system so that it is possible to select different frequencies and induce waves according to the objective depth to be explored. During processing not only resistivity but also polarization information can be provided so we can study resistivity as well as predict oil-bearing characteristics simultaneously. Timedomain resistivity information is obtained by pseudo-2D resistivity inversion and frequencydomain IP information is obtained using the Cole-Cole model. Some successful applications in western China show that it provides unique results in an overthrust zone, deep igneous rock investigation, and hydrocarbon prediction.
基金supported by the National Program for Fundamental Research and Development (973 Program 2006CB202306)
文摘There are some differences in reservoir quality of clastic rock between the hanging wall and the foot wall of the Ke-Bai overthrust belt, northwestern margin of the Junggar Basin, western China, which affect the efficient petroleum exploration in this highly mature exploration area. Based on a large number of thin-sections, cast thin-sections, and physical property analysis of cores, we systematically discuss the Permian-Jurassic reservoir differences between the hanging wall and the foot wall of the Ke- Bai overthrust fault from the aspects of structural evolution, time-space distribution of the depositional system, diagenesis characteristics, and reservoir quality and analyzed the reasons for the differences in reservoir properties. The overthrusting of the Ke-Bai fault directly results in different burial histories, diagenesis evolution, and porosity evolution between the hanging wall and the foot wall. The diflbrences of reservoir characteristics are mainly embodied in buried depth, grain size, sedimentary facies, diagenetic stage, and reservoir quality. The analysis results showed that burial history and depositional characteristics controlled by overthrusting are direct influencing factors of reservoir differences. Because of shallow burial depth of the hanging wall, the reservoir compaction is weak and primary pores are preserved well. The porosity of reservoir on the hanging wall is generally 10%-25%. The strata on the foot wall are deeply buried, and there are mainly mixed pores with the average porosity of 5%-20%. The favorable reservoir on the foot wall is generally developed near faults or in the channel sand bodies, which are usually dissolution development areas.
文摘On the basis of interpretation of comprehensive geophysical data and foreign data analysis,there existed a lot of overburden detachment shear thrust faults along the southeastern margin of Nansha Trough,which composed imbricated overthrust nappe structure.Thrust-faulted nappe structure pattern is determined in this area,which consists of frontal fault zone,thrust fault-folded zone and root zone structures,and presents regularly zonation on plane.The detail description of the structural geometrical characteristics is given in shallow thrust fault zone,and the kinematical mechanism of thrust fault nappe structure is furtherly discussed.Overthrnst nappe structure in this area is resulted from island arc-continent collision and orogenic activities.
文摘The region around the Karamay-Baikouquan （Ke-Bai） overthrust belt is the richest in hydrocarbon accumulation in the Junggar Basin. Previous research has indicated that oil in the region came from the Fengcheng Formation in the Mahu Depression to the northeast of the region, but the oil distribution around the Mahu Depression is remarkably uneven. Large amounts of oil have been found in the Ke-Bai overthrust belt to the west of the depression and only some small oilfields have been discovered in the eastern margin of the depression. This uneven distribution revealed that the oil source of the Ke- Bai region might not be from the Mahu Depression. The oil type distribution and the oil migration pattern revealed in this paper showed that there may be another oil source under the Karamay overthrust. Based on geochemical data, the oil was classified into two types from the sterane and terpane characteristics. Type A oil was mainly distributed in the Huwan area and blocks V and VIII of the Karamay Oilfield in the southern part of the region, while type B oil was mainly distributed in the Baikouquan Oilfield in the northern part of the region. In addition, oil migration pathways and direction were determined by the values of diasterane / regular sterane and C30 moretane / C30 hopane ratios. It is shown that the oil of Huwan area on the hanging wall of the overthrust was mainly charged along the overthrust fault surfaces and then migrated to the west, whereas the oil in blocks V and VIII on the foot wall of the overthrust came from the Mahu Depression in the east. As a result, there may be at least two hydrocarbon source kitchens in the study area. The hydrocarbons in the blocks V and VIII on the footwall of the overthrust belt and in the Baikouquan Oilfield mainly came from the Fengcheng Formation in the Mahu Depression, and the hydrocarbons in the Huwan area on the hanging wall of the overthrust belt may come from another hydrocarbon source kitchen below the overthrust. This recognition indicates that there is substantial exploration potential in the deep Carboniferous strata on the hanging wall of the overthrust belt.
文摘The arcuate nappe structure on the north edge of the Wuliang Mountains in westernYunnan Province is a complex nappe structural system with multiple superimposed structures.The autochthonous system is a WNW-trending arcuate fold belt consisting of the Jurassic andCretaceous and the allochthonous system is mainly composed of Upper Triassic rocks. Generally,the nappe structure moved from south to north, with the hanging wall thrusting in a WNW direc-tion for a distance of over 10km. The deep nappe structural system was formed at depths ofabout 5-10km in an environment not exceeding the greenschist facies. It occurred in theOligocene (about 40-20 Ma).
文摘The external thrustbelt of Albania consists of some tectonic zones(Ionian,Kruja and Krasta-Cukali zones),that are westward overthrust,with a large amplitude(50e100 km),above the Apulian platform and South Adriatic Basin.The relative movement of the Adriatico-Apulian sub-plate between,the Euro Asiatic and African plates during from the Mesozoic to the Tertiary period,mainly controlled the tectonic evolution of the Albanides.The Ionian zone consists of anticline belts(Berati,Kurveleshi and Cika),that are overthrust toward the west with an amplitude about 20e30 km Their overthrustings was realized through regional sliding evaporitic horizons,which caused the masking of folded structures in the subthrust,with the perspective plays.The Kurveleshi anticlinal belt represents a mega-anticlinal with a length of 210 km and a width of about 20 km,and it is characterized by anticline structures with heterogeneous dimensions,predominantly those of great dimensions and linear type.The overthrusting of the anticline units has a local character,and it is more developed in the Kurveleshi anticlinal belt.Its magnitude is about 8e10 km.As a result of these overthrusts,imbrication and duplex styles are formed,leadind to the masking of the subthrust complex with structures of large interest(e.g.Delvina,Karbunara,etc.)where two oil fields have been dioscovered beneath the Mali Gjere anticline(Delvina oil field)and the Kremenara anticline(Karbunara oil field).Backthrust faults phenomena are secondary and they taken place in the post-collision stage.Generally they are easterward thrust faults of structural units with an amplitude of 5e10 km.The Kurveleshi anticlinal belt,based on tectonic features,is divided into two parts:The southern part,from Qafa Sevaster in the north down to Greece to the south.and northern part,from Qafa Sevaster in the south up to the end of the Patos-Verbas structure.In the southern part these features predominate:The anticline structures are large in size,and overthrust with a large amplitude(8e10 km)westward.The evaporitic diapirs have erupted through local faults of the anticline structures of the Kurveleshi anticlinal belt(Mali Gjere,Kurveleshi and Fterra anticlines).These eruptions(Delvina,Picar-Kapariel-Bashaj,etc.)have helped in the overthrusting of these structural units.It must be mentioned that the backthrusting is also affected by the diapir action.Moreover,vertical diapir occur,in the center of the structures like Navarica.In the northern part,the anticline structures are generally small to medium in size.Only the Patos-Verbas anticline is larger in size.In the Kurveleshi anticlinal belt the Ballsh and Visoka oilfields have developed.The eastern flank of the Shushica synclinal belt apears folded,and the carbonate anticline structures have developed.Existing oil fields include the Gorisht-Kocul,Cakran-Moallaj-Kreshpan and Amonica.These oil fields shoud continue towards the north(under the overthrust of the Patos-Verbas antcline)and in the south(under the regional ovethrust of the Kuervelesh anticlinal belt).
