In response to the problems of unclear distribution of deep-water pre-salt carbonate reservoirs and formation conditions of large oil fields in the Santos passive continental margin basin,based on comprehensive utiliz...In response to the problems of unclear distribution of deep-water pre-salt carbonate reservoirs and formation conditions of large oil fields in the Santos passive continental margin basin,based on comprehensive utilization of geological,seismic,and core data,and reconstruction of Early Cretaceous prototype basin and lithofacies paleogeography,it is proposed for the first time that the construction of pre-salt carbonate build-ups was controlled by two types of isolated platforms:inter-depression fault-uplift and intra-depression fault-high.The inter-depression fault-uplift isolated platforms are distributed on the present-day pre-salt uplifted zones between depressions,and are built on half-and fault-horst blocks that were inherited and developed in the early intra-continental and inter-continental rift stages.The late intra-continental rift coquinas of the ITP Formation and the early inter-continental rift microbial limestones of the BVE Formation are continuously constructed;intra-depression fault-high isolated platforms are distributed in the current pre-salt depression zones,built on the uplifted zones formed by volcanic rock build-ups in the early prototype stage of intra-continental rifts,and only the BVE microbial limestones are developed.Both types of limestones formed into mound-shoal bodies,that have the characteristics of large reservoir thickness and good physical properties.Based on the dissection of large pre-salt oil fields discovered in the Santos Basin,it has been found that both types of platforms could form large-scale combined structural-stratigraphic traps,surrounded by high-quality lacustrine and lagoon source rocks at the periphery,and efficiently sealed by thick high-quality evaporite rocks above,forming the optimal combination of source,reservoir and cap in the form of“lower generation,middle storage,and upper cap”,with a high degree of oil and gas enrichment.It has been found that the large oil fields are all bottom water massive oil fields with a unified pressure system,and they are all filled to the spill-point.The future exploration is recommended to focus on the inter-depression fault-uplift isolated platforms in the western uplift zone and the southern section of eastern uplift zones,as well as intra-depression fault-high isolated platforms in the central depression zone.The result not only provides an important basis for the advanced selection of potential play fairways,bidding of new blocks,and deployment of awarded exploration blocks in the Santos Basin,but also provides a reference for the global selection of deep-water exploration blocks in passive continental margin basins.展开更多
通过收集相关基础资料和数据,基于中国土壤流失方程计算出四川省级水土流失动态监测区土壤侵蚀状况,并将监测结果与2011年第一次全国水利普查水土保持情况普查成果进行对比分析。结果表明:监测区水土流失面积为36945.20 km 2,占动态监...通过收集相关基础资料和数据,基于中国土壤流失方程计算出四川省级水土流失动态监测区土壤侵蚀状况,并将监测结果与2011年第一次全国水利普查水土保持情况普查成果进行对比分析。结果表明:监测区水土流失面积为36945.20 km 2,占动态监测区总面积的27.16%,区内整体土壤侵蚀程度较轻,但侵蚀分布空间异质性明显,局部地区仍存在严重水土流失;监测区水土流失面积减少率为4.85%,且水土流失强度由高强度转向低强度,但水土流失消长情况具有空间差异性,川西地区部分区县水土流失面积仍有小幅增加。近年来四川省水土流失治理力度加大,对改善监测区水土流失起到了积极作用,但局部地区仍要加强水土流失预防监督工作。展开更多
Based on regional geology,2D seismic and ocean drilling data,the formation of the Eratosthenes Seamount(ESM)and its surrounding isolated platforms,types of organic reefs and hydrocarbon accumulation conditions in the ...Based on regional geology,2D seismic and ocean drilling data,the formation of the Eratosthenes Seamount(ESM)and its surrounding isolated platforms,types of organic reefs and hydrocarbon accumulation conditions in the eastern Mediterranean were analyzed through fine tectonic interpretation and seismic facies study,and the future exploration targets were pointed out.The formation and evolution of the ESM and its peripheral isolated platforms are highly related to the open and close of the Neotethyan ocean.The precursors of the ESM and its peripheral isolated platforms are both horst-type fault blocks formed in the Middle Triassic-Early Jurassic intracontinental rift stage.The ESM and its peripheral isolated platforms underwent continued and inherited carbonate build-ups during the Middle Jurassic intercontinental rift stage,the Late Jurassic-Late Cretaceous Turonian passive drift stage,and Late Cretaceous Senonian-Miocene subduction stage,as well as medium-slight inversion transformation beginning in the Late Miocene Messinian caused by the closure of the Neotethyan ocean.Three types of isolated platforms formed controlled by variant paleo-tectonic settings:the first type is composed of a single patch-like reef controlled by a small-scale and narrow horst-type fault block,the second type consists of a single atoll controlled by a middle-scale and wide horst-type fault block,and the third type is comprised of multiple reef-beach complexes controlled by a large-scale and broad paleo-high.The first two types universally developed in the highs of the alternate sag-uplift structural zones on the south and west of Eratosthenes,and the third type only developed in the ESM.As a result of fluctuation of sea level,two sequences of reef build-ups,i.e.the Middle Jurassic Bajocian-Upper Cretaceous Turonian and the Miocene,developed in the ESM as well as the highs in the alternate sag-uplift structural zones on the south and west of Eratosthenes.Drillings have confirmed that the first two types of isolated platforms with a single patch-like reef and a single circle-like reef have good conditions for natural gas accumulations.The isolated platform of reef-beach complexes in the ESM also has accumulation potentials of natural gas and is worth prospecting.展开更多
基金Supported by the National Science and Technology Major Project(2016ZX05029001)CNPC Science and Technology Project(2019D-4310)。
文摘In response to the problems of unclear distribution of deep-water pre-salt carbonate reservoirs and formation conditions of large oil fields in the Santos passive continental margin basin,based on comprehensive utilization of geological,seismic,and core data,and reconstruction of Early Cretaceous prototype basin and lithofacies paleogeography,it is proposed for the first time that the construction of pre-salt carbonate build-ups was controlled by two types of isolated platforms:inter-depression fault-uplift and intra-depression fault-high.The inter-depression fault-uplift isolated platforms are distributed on the present-day pre-salt uplifted zones between depressions,and are built on half-and fault-horst blocks that were inherited and developed in the early intra-continental and inter-continental rift stages.The late intra-continental rift coquinas of the ITP Formation and the early inter-continental rift microbial limestones of the BVE Formation are continuously constructed;intra-depression fault-high isolated platforms are distributed in the current pre-salt depression zones,built on the uplifted zones formed by volcanic rock build-ups in the early prototype stage of intra-continental rifts,and only the BVE microbial limestones are developed.Both types of limestones formed into mound-shoal bodies,that have the characteristics of large reservoir thickness and good physical properties.Based on the dissection of large pre-salt oil fields discovered in the Santos Basin,it has been found that both types of platforms could form large-scale combined structural-stratigraphic traps,surrounded by high-quality lacustrine and lagoon source rocks at the periphery,and efficiently sealed by thick high-quality evaporite rocks above,forming the optimal combination of source,reservoir and cap in the form of“lower generation,middle storage,and upper cap”,with a high degree of oil and gas enrichment.It has been found that the large oil fields are all bottom water massive oil fields with a unified pressure system,and they are all filled to the spill-point.The future exploration is recommended to focus on the inter-depression fault-uplift isolated platforms in the western uplift zone and the southern section of eastern uplift zones,as well as intra-depression fault-high isolated platforms in the central depression zone.The result not only provides an important basis for the advanced selection of potential play fairways,bidding of new blocks,and deployment of awarded exploration blocks in the Santos Basin,but also provides a reference for the global selection of deep-water exploration blocks in passive continental margin basins.
文摘通过收集相关基础资料和数据,基于中国土壤流失方程计算出四川省级水土流失动态监测区土壤侵蚀状况,并将监测结果与2011年第一次全国水利普查水土保持情况普查成果进行对比分析。结果表明:监测区水土流失面积为36945.20 km 2,占动态监测区总面积的27.16%,区内整体土壤侵蚀程度较轻,但侵蚀分布空间异质性明显,局部地区仍存在严重水土流失;监测区水土流失面积减少率为4.85%,且水土流失强度由高强度转向低强度,但水土流失消长情况具有空间差异性,川西地区部分区县水土流失面积仍有小幅增加。近年来四川省水土流失治理力度加大,对改善监测区水土流失起到了积极作用,但局部地区仍要加强水土流失预防监督工作。
基金Supported by the China National Science and Technology Major Project(2016ZX05029001)the CNPC Science and Technology Project(2019D-4310)。
文摘Based on regional geology,2D seismic and ocean drilling data,the formation of the Eratosthenes Seamount(ESM)and its surrounding isolated platforms,types of organic reefs and hydrocarbon accumulation conditions in the eastern Mediterranean were analyzed through fine tectonic interpretation and seismic facies study,and the future exploration targets were pointed out.The formation and evolution of the ESM and its peripheral isolated platforms are highly related to the open and close of the Neotethyan ocean.The precursors of the ESM and its peripheral isolated platforms are both horst-type fault blocks formed in the Middle Triassic-Early Jurassic intracontinental rift stage.The ESM and its peripheral isolated platforms underwent continued and inherited carbonate build-ups during the Middle Jurassic intercontinental rift stage,the Late Jurassic-Late Cretaceous Turonian passive drift stage,and Late Cretaceous Senonian-Miocene subduction stage,as well as medium-slight inversion transformation beginning in the Late Miocene Messinian caused by the closure of the Neotethyan ocean.Three types of isolated platforms formed controlled by variant paleo-tectonic settings:the first type is composed of a single patch-like reef controlled by a small-scale and narrow horst-type fault block,the second type consists of a single atoll controlled by a middle-scale and wide horst-type fault block,and the third type is comprised of multiple reef-beach complexes controlled by a large-scale and broad paleo-high.The first two types universally developed in the highs of the alternate sag-uplift structural zones on the south and west of Eratosthenes,and the third type only developed in the ESM.As a result of fluctuation of sea level,two sequences of reef build-ups,i.e.the Middle Jurassic Bajocian-Upper Cretaceous Turonian and the Miocene,developed in the ESM as well as the highs in the alternate sag-uplift structural zones on the south and west of Eratosthenes.Drillings have confirmed that the first two types of isolated platforms with a single patch-like reef and a single circle-like reef have good conditions for natural gas accumulations.The isolated platform of reef-beach complexes in the ESM also has accumulation potentials of natural gas and is worth prospecting.
