Based on the seismic and drilling data, casting thin sections, geochemical analysis of oil and rock samples, and hydrocarbon generation history simulation, the hydrocarbon accumulation characteristics and exploration ...Based on the seismic and drilling data, casting thin sections, geochemical analysis of oil and rock samples, and hydrocarbon generation history simulation, the hydrocarbon accumulation characteristics and exploration direction of Termit superimposed marine–continental rift basin are discussed. The Termit basin is superimposed with two-phase rifts(Early Cretaceous and Paleogene). The subsidence curves from two wells on the Trakes slope in the east of the basin show high subsidence rate in the Late Cretaceous, which is believed to be high deposition rate influenced by transgression. However, a weak rift may also be developed. The depositional sequences in the Termit basin were controlled by the Late Cretaceous marine transgression cycle and the Paleogene lacustrine transgression cycle, giving rise to two types of superimposed marine–continental “source-sink” deposits. The marine and continental mixed source rocks developed universally in the whole basinduring the marine transgression period, and are overlaid by the Paleogene Sokor 1 reservoir rocks and Sokor 2 caprocks developed during the lacustrine transgression period, forming the unique superimposed marine–continental basin in WCARS. The early low geothermal gradient in the Termit basin resulted in the late hydrocarbon generated by the source rock of Upper Cretaceous Yogou in Paleogene. Mature source rock of Upper Cretaceous Donga developed in the Trakes slope, so that the double-source-supply hydrocarbon and accumulation models are proposed for the Trakes slope in which formed the oil fields. Due to virtue of the newly proposed hydrocarbon accumulation model and the exploration activities in recent years in the Termit superimposed marine–continental rift basin, an additional effective exploration area of about 2500 km2has been confirmed in the east of the basin. It is believed that potential domains such as Sokor 1, Donga and Upper Cretaceous lithologic traps in the southeast of the basin are key expected targets for exploration and frontier evaluation in future.展开更多
Commercial hydrocarbon reservoirs have been discovered in shallow-water areas of the Scotian Basin, Eastern Canada. However, knowledge about the structure and hydrocarbon accumulation characteristics of the basin is s...Commercial hydrocarbon reservoirs have been discovered in shallow-water areas of the Scotian Basin, Eastern Canada. However, knowledge about the structure and hydrocarbon accumulation characteristics of the basin is still insufficient, which constrains the oil and gas exploration in deep-water areas. Based on comprehensive data of magnetic anomalies, seismic survey, and drilling, this study determines the structure characteristics of the Scotian Basin and its hydrocarbon accumulation conditions in deep waters and evaluates the deep-water hydrocarbon exploration potential. The transform faults and basement structures in the northern basin control the sedimentary framework showing thick strata in east and thin strata in west of the basin. The bowl-shaped depression formed by thermal subsidence during the transitional phase and the confined environment (micro basins) caused by salt tectonics provide favorable conditions for the development of source rocks during the depression stage (also referred to as the depression period sequence) of the basin. The progradation of large shelf-margin deltas during the drift phase and steep continental slope provide favorable conditions for the deposition of slope-floor fans on continental margins of the basin. Moreover, the source-reservoir assemblage comprising the source rocks within the depression stage and the turbidite sandstones on the continental margin in the deep waters may form large deep-water turbidite sandstone reservoirs. This study will provide a valuable reference for the deep-water hydrocarbon exploration in the Scotian Basin.展开更多
Based on outcrop,seismic and drilling data,the main regional unconformities in the Sichuan Basin and their controls on hydrocarbon accumulation were systematically studied.Three findings are obtained.First,six regiona...Based on outcrop,seismic and drilling data,the main regional unconformities in the Sichuan Basin and their controls on hydrocarbon accumulation were systematically studied.Three findings are obtained.First,six regional stratigraphic unconformities are mainly developed in the Sichuan Basin,from the bottom up which are between pre-Sinian and Sinian,between Sinian and Cambrian,between pre-Permian and Permian,between middle and upper Permian,between middle and upper Triassic,and between Triassic and Jurassic.Especially,16 of 21l conventional(and tight)gas fields discovered are believed to have formed in relation to regional unconformities.Second,regional unconformity mainly controls hydrocarbon accumulation from five aspects:(1)The porosity and permeability of reservoirs under the unconformity are improved through weathering crust karstification to form large-scale karst reservoirs;(2)Good source-reservoir-caprock assemblage can form near the unconformity,which provides a basis for forming large gas field;(3)Regional unconformity may lead to stratigraphic pinch-out and rugged ancient landform,giving rise to a large area of stratigraphic and lithologic trap groups;(4)Regional unconformity provides a dominant channel for lateral migration of oil and gas;and(5)Regional unconformity is conducive to large-scale accumulation of oil and gas.Third,the areas related to regional unconformities are the exploration focus of large gas fields in the Sichuan Basin.The pre-Sinian is found with source rocks,reservoir rocks and other favorable conditions for the formation of large gas fields,and presents a large exploration potential.Thus,it is expected to be an important strategic replacement.展开更多
The purpose of this paper is to discuss the poly-phase salt tectonics and its relation to the hydrocarbon accumulation of the Tarim superimposed basin. Several salt sequences are developed in the Tarim basin, they are...The purpose of this paper is to discuss the poly-phase salt tectonics and its relation to the hydrocarbon accumulation of the Tarim superimposed basin. Several salt sequences are developed in the Tarim basin, they are: (1) the Mid-Early Cambrian salt sequence, mainly distributed in the west part of the north Tarim uplift and Keping uplift; (2) the Early Carboniferous salt sequence, mainly distributed in the south slope of the north Tarim uplift; (3) the Paleogene salt sequence, mainly distributed in the mid-west part of the Kuqa foreland fold belt and north Tarim uplift; and (4) the Miocene salt sequence, mainly distributed in the east part of the Kuqa foreland fold belt. The salt sequences deposited in the tectonically calm scenario, while the salt layers deformed during the period of intense tectonism. Although the salt sequences are characteristic of plastic flow, the differences of salt deformation styles exist in the different salt sequences be-cause of the different deformation mechanism. It is attractive that the distribution of the large oil-gas fields or pools has a bearing upon the salt sequences and salt structures, such as the Tahe oilfield related to the Lower Carboniferous salt sequence and laterally facies changed mudstone, the Kela No.2 gas field to the Paleogene salt structures, and the Dina gas field to the Miocene salt structures. It is indicated that the large-scale hydrocarbon accumulation is con-trolled by the poly-phase salt sequences and structures. The deep analysis of the poly-phase salt tectonics is helpful to understanding the characteristics of the structural deformation and oil-gas accumulation of the Tarim basin.展开更多
我国石油公司在中东阿曼山西侧前陆盆地莱克维尔隆起拥有多个油气合作项目,由于勘探程度较低,对其区域构造与油气成藏特征的认识还不够深入。基于新的井震资料,开展莱克维尔隆起区构造、断裂解释与油气成藏分析。结果表明:①莱克维尔隆...我国石油公司在中东阿曼山西侧前陆盆地莱克维尔隆起拥有多个油气合作项目,由于勘探程度较低,对其区域构造与油气成藏特征的认识还不够深入。基于新的井震资料,开展莱克维尔隆起区构造、断裂解释与油气成藏分析。结果表明:①莱克维尔隆起在三叠纪—侏罗纪处于拉张环境,晚白垩世构造发生反转形成反转背斜,其形成主要受控于阿曼山快速隆升挤压作用,上覆古近系直接披覆于隆起区中白垩统之上呈不整合接触。②隆起区发育两组高角度正断层,断层形态在剖面上呈“Y”形、复合“Y”形,在平面上呈“X”形交叉分布;晚白垩世由于造山作用导致断层处于挤压状态。③研究区中生代长期处于被动陆缘,具有3类典型成藏模式,包括下白垩统Shuaiba组礁滩岩性油气藏、上白垩统Natih组断块型油气藏及地层不整合油气藏、古近系Umm er Radhuma组生物碎屑灰岩岩性油气藏;晚白垩世以来上侏罗统Diyab组、下白垩统Bab组2套主力烃源岩已进入成熟阶段,晚白垩世发育的不整合及三叠纪—侏罗纪伸展背景下形成的垂向断裂构成重要的油气输导体系,促进了区域油气聚集成藏。认为莱克维尔隆起顶部、西侧斜坡带与东侧前渊斜坡带的地质条件相似,具有较大勘探潜力,是未来重要的油气勘探方向。展开更多
The northern area of the South Yellow Sea, located in the offshore region of China, resulted from the continental-continental collision orogeny during the Mesozoic and can be divided into four stages in terms of tecto...The northern area of the South Yellow Sea, located in the offshore region of China, resulted from the continental-continental collision orogeny during the Mesozoic and can be divided into four stages in terms of tectonic evolution: (1) pre-orogenic passive continental margin stage (Z-T2); (2) foreland basin stage corresponding with the late phase of the Sulu (苏鲁) orogeny (J3-K); (3) post-orogenic intracontinental rifted basin stage (K2t-E); and (4) regional subsidence and coverage stage (N-Q). Based on detailed investigation and study of the intracontinental rifted basin, hydrocar- bon source rocks of Late Cretaceous Taizhou (泰州) Formation distributed well in the basin, and four reservoir-cap combinations as well as numerous trap structures were found. As a result, the geological conditions would be excellent for reservoir formation in the basin, and the oil resource amount is estimated at about 20×10^8 t, which makes the basin a major target for hydrocarbon exploration in the South Yellow Sea.展开更多
基金Supported by CNPC Scientific Research and Technology Development Project (2021DJ3103)CNODC Overseas Rresearch and Development Support Project (2023-YF-01-04)。
文摘Based on the seismic and drilling data, casting thin sections, geochemical analysis of oil and rock samples, and hydrocarbon generation history simulation, the hydrocarbon accumulation characteristics and exploration direction of Termit superimposed marine–continental rift basin are discussed. The Termit basin is superimposed with two-phase rifts(Early Cretaceous and Paleogene). The subsidence curves from two wells on the Trakes slope in the east of the basin show high subsidence rate in the Late Cretaceous, which is believed to be high deposition rate influenced by transgression. However, a weak rift may also be developed. The depositional sequences in the Termit basin were controlled by the Late Cretaceous marine transgression cycle and the Paleogene lacustrine transgression cycle, giving rise to two types of superimposed marine–continental “source-sink” deposits. The marine and continental mixed source rocks developed universally in the whole basinduring the marine transgression period, and are overlaid by the Paleogene Sokor 1 reservoir rocks and Sokor 2 caprocks developed during the lacustrine transgression period, forming the unique superimposed marine–continental basin in WCARS. The early low geothermal gradient in the Termit basin resulted in the late hydrocarbon generated by the source rock of Upper Cretaceous Yogou in Paleogene. Mature source rock of Upper Cretaceous Donga developed in the Trakes slope, so that the double-source-supply hydrocarbon and accumulation models are proposed for the Trakes slope in which formed the oil fields. Due to virtue of the newly proposed hydrocarbon accumulation model and the exploration activities in recent years in the Termit superimposed marine–continental rift basin, an additional effective exploration area of about 2500 km2has been confirmed in the east of the basin. It is believed that potential domains such as Sokor 1, Donga and Upper Cretaceous lithologic traps in the southeast of the basin are key expected targets for exploration and frontier evaluation in future.
基金supported by the National Science and Technology Major Project of China(2016ZX05033)the Project of SINOPEC Science and Technology Department(P19021-2)the Basic Prospective Research Project of SINOPEC(P22214-2).
文摘Commercial hydrocarbon reservoirs have been discovered in shallow-water areas of the Scotian Basin, Eastern Canada. However, knowledge about the structure and hydrocarbon accumulation characteristics of the basin is still insufficient, which constrains the oil and gas exploration in deep-water areas. Based on comprehensive data of magnetic anomalies, seismic survey, and drilling, this study determines the structure characteristics of the Scotian Basin and its hydrocarbon accumulation conditions in deep waters and evaluates the deep-water hydrocarbon exploration potential. The transform faults and basement structures in the northern basin control the sedimentary framework showing thick strata in east and thin strata in west of the basin. The bowl-shaped depression formed by thermal subsidence during the transitional phase and the confined environment (micro basins) caused by salt tectonics provide favorable conditions for the development of source rocks during the depression stage (also referred to as the depression period sequence) of the basin. The progradation of large shelf-margin deltas during the drift phase and steep continental slope provide favorable conditions for the deposition of slope-floor fans on continental margins of the basin. Moreover, the source-reservoir assemblage comprising the source rocks within the depression stage and the turbidite sandstones on the continental margin in the deep waters may form large deep-water turbidite sandstone reservoirs. This study will provide a valuable reference for the deep-water hydrocarbon exploration in the Scotian Basin.
基金Supported by the National Natural Science Foundation Project of China(U22B6002)Prospective Basic Technology Research Project of PetroChina(2021DJ0605).
文摘Based on outcrop,seismic and drilling data,the main regional unconformities in the Sichuan Basin and their controls on hydrocarbon accumulation were systematically studied.Three findings are obtained.First,six regional stratigraphic unconformities are mainly developed in the Sichuan Basin,from the bottom up which are between pre-Sinian and Sinian,between Sinian and Cambrian,between pre-Permian and Permian,between middle and upper Permian,between middle and upper Triassic,and between Triassic and Jurassic.Especially,16 of 21l conventional(and tight)gas fields discovered are believed to have formed in relation to regional unconformities.Second,regional unconformity mainly controls hydrocarbon accumulation from five aspects:(1)The porosity and permeability of reservoirs under the unconformity are improved through weathering crust karstification to form large-scale karst reservoirs;(2)Good source-reservoir-caprock assemblage can form near the unconformity,which provides a basis for forming large gas field;(3)Regional unconformity may lead to stratigraphic pinch-out and rugged ancient landform,giving rise to a large area of stratigraphic and lithologic trap groups;(4)Regional unconformity provides a dominant channel for lateral migration of oil and gas;and(5)Regional unconformity is conducive to large-scale accumulation of oil and gas.Third,the areas related to regional unconformities are the exploration focus of large gas fields in the Sichuan Basin.The pre-Sinian is found with source rocks,reservoir rocks and other favorable conditions for the formation of large gas fields,and presents a large exploration potential.Thus,it is expected to be an important strategic replacement.
基金jointly supported by the National Major Fundamental Research and Development Project(Grant No.G19990433)the National Natural Science Foundation of China(Grant No.40172076)the National Key Project of Ninth Five-Year Plan(No.99-111).
文摘The purpose of this paper is to discuss the poly-phase salt tectonics and its relation to the hydrocarbon accumulation of the Tarim superimposed basin. Several salt sequences are developed in the Tarim basin, they are: (1) the Mid-Early Cambrian salt sequence, mainly distributed in the west part of the north Tarim uplift and Keping uplift; (2) the Early Carboniferous salt sequence, mainly distributed in the south slope of the north Tarim uplift; (3) the Paleogene salt sequence, mainly distributed in the mid-west part of the Kuqa foreland fold belt and north Tarim uplift; and (4) the Miocene salt sequence, mainly distributed in the east part of the Kuqa foreland fold belt. The salt sequences deposited in the tectonically calm scenario, while the salt layers deformed during the period of intense tectonism. Although the salt sequences are characteristic of plastic flow, the differences of salt deformation styles exist in the different salt sequences be-cause of the different deformation mechanism. It is attractive that the distribution of the large oil-gas fields or pools has a bearing upon the salt sequences and salt structures, such as the Tahe oilfield related to the Lower Carboniferous salt sequence and laterally facies changed mudstone, the Kela No.2 gas field to the Paleogene salt structures, and the Dina gas field to the Miocene salt structures. It is indicated that the large-scale hydrocarbon accumulation is con-trolled by the poly-phase salt sequences and structures. The deep analysis of the poly-phase salt tectonics is helpful to understanding the characteristics of the structural deformation and oil-gas accumulation of the Tarim basin.
文摘我国石油公司在中东阿曼山西侧前陆盆地莱克维尔隆起拥有多个油气合作项目,由于勘探程度较低,对其区域构造与油气成藏特征的认识还不够深入。基于新的井震资料,开展莱克维尔隆起区构造、断裂解释与油气成藏分析。结果表明:①莱克维尔隆起在三叠纪—侏罗纪处于拉张环境,晚白垩世构造发生反转形成反转背斜,其形成主要受控于阿曼山快速隆升挤压作用,上覆古近系直接披覆于隆起区中白垩统之上呈不整合接触。②隆起区发育两组高角度正断层,断层形态在剖面上呈“Y”形、复合“Y”形,在平面上呈“X”形交叉分布;晚白垩世由于造山作用导致断层处于挤压状态。③研究区中生代长期处于被动陆缘,具有3类典型成藏模式,包括下白垩统Shuaiba组礁滩岩性油气藏、上白垩统Natih组断块型油气藏及地层不整合油气藏、古近系Umm er Radhuma组生物碎屑灰岩岩性油气藏;晚白垩世以来上侏罗统Diyab组、下白垩统Bab组2套主力烃源岩已进入成熟阶段,晚白垩世发育的不整合及三叠纪—侏罗纪伸展背景下形成的垂向断裂构成重要的油气输导体系,促进了区域油气聚集成藏。认为莱克维尔隆起顶部、西侧斜坡带与东侧前渊斜坡带的地质条件相似,具有较大勘探潜力,是未来重要的油气勘探方向。
基金supported by the National Natural Science Foundation of China (No. 40620140435)
文摘The northern area of the South Yellow Sea, located in the offshore region of China, resulted from the continental-continental collision orogeny during the Mesozoic and can be divided into four stages in terms of tectonic evolution: (1) pre-orogenic passive continental margin stage (Z-T2); (2) foreland basin stage corresponding with the late phase of the Sulu (苏鲁) orogeny (J3-K); (3) post-orogenic intracontinental rifted basin stage (K2t-E); and (4) regional subsidence and coverage stage (N-Q). Based on detailed investigation and study of the intracontinental rifted basin, hydrocar- bon source rocks of Late Cretaceous Taizhou (泰州) Formation distributed well in the basin, and four reservoir-cap combinations as well as numerous trap structures were found. As a result, the geological conditions would be excellent for reservoir formation in the basin, and the oil resource amount is estimated at about 20×10^8 t, which makes the basin a major target for hydrocarbon exploration in the South Yellow Sea.