The Triassic Jialingjiang Formation and Leikoupo Formation are characterized by thick salt layers. Three tectono-stratigraphic sequences can be identified according to detachment layers of Lower-Middle Triassic salt b...The Triassic Jialingjiang Formation and Leikoupo Formation are characterized by thick salt layers. Three tectono-stratigraphic sequences can be identified according to detachment layers of Lower-Middle Triassic salt beds in the northern Sichuan Basin, i.e. the sub-salt sequence composed of Sinian to the Lower Triassic Feixianguan Formation, the salt sequence of the Lower Triassic Jialingjiang Formation and Mid-Triassic Leikoupou Formation, and the supra-salt sequence composed of continental clastics of the Upper-Triassic Xujiahe Formation, Jurassic and Cretaceous. A series of specific structural styles, such as intensively deformed belt of basement-involved imbricated thrust belt, basement-involved and salt-detached superimposed deformed belt, buried salt-related detached belt, duplex, piling triangle zone and pop-up, developed in the northern Sichuan Basin. The relatively thin salt beds, associated with the structural deformation of the northern Sichuan Basin, might act as a large decollement layer. The deformation mechanisms in the northern Sichuan Basin included regional compression and shortening, plastic flow and detachment, tectonic upwelling and erosion, gravitational sliding and spreading. The source rocks in the northern Sichuan Basin are strata underlying the salt layer, such as the Cambrian, Silurian and Permian. The structural deformation related to the Triassic salt controlled the styles of traps for hydrocarbon. The formation and development of hydrocarbon traps in the northern Sichuan Basin might have a bearing upon the Lower-Middle Triassic salt sequences which were favorable to the hydrocarbon accumulation and preservation. The salt layers in the Lower-Middle Triassic formed the main cap rocks and are favorable for the accumulation and preservation of hydrocarbon.展开更多
This study investigated the characteristics and genesis of reservoirs in the 2^(nd) and 4^(th) members of Sinian Dengying Formation in northern Sichuan and its surrounding areas, on the basis of outcrop, drilling core...This study investigated the characteristics and genesis of reservoirs in the 2^(nd) and 4^(th) members of Sinian Dengying Formation in northern Sichuan and its surrounding areas, on the basis of outcrop, drilling cores and thin section observation and geochemical analysis. The reservoirs of 2^(nd) member are distributed in the middle part of the stratum. The reservoir quality is controlled by supergene karst and the distribution of mound-shoal complex. The bedded elongated isolated algal framework solution-cave and the residual "grape-lace" cave, which are partially filled with multi-stage dolosparite, constituted the main reservoir space of the 2^(nd) member. There is no asphalt distribution in the pores. The pore connectivity is poor, and the porosity and permeability of the reservoir is relatively low. The reservoirs of 4^(th) member were distributed in the upper and top part of the stratum. The reservoir quality is controlled by burial dissolution and the distribution of mound-shoal complex. The bedded algal framework solution-pores or caves, intercrystalline pores and intercrystalline dissolved pores constituted the main reservoir space of the 4^(th) member. It's partially filled with asphalt and quartz, without any dolosparite fillings in the pores and caves. The pore connectivity is good. Most of the 4^(th) member reservoirs had medium-low porosity and low permeability, and, locally, medium-high porosity and medium permeability. Affected by the development of mound-shoal complex and heterogeneous dissolution, the platform margin along Ningqiang, Guangyuan, Jiange and Langzhong is the most favorable region for reservoir development. Deep buried Dengying Formation in the guangyuan and langzhong areas should be the most important hydrocarbon target for the future exploration.展开更多
Described in detail in this paper are the geochemical charederistics of thesandstone-type urboum deposits in northern Sichuan Province. Favoable and unfavor-able conditions for the enrichment of uranium are explored o...Described in detail in this paper are the geochemical charederistics of thesandstone-type urboum deposits in northern Sichuan Province. Favoable and unfavor-able conditions for the enrichment of uranium are explored on the basis of the elementalabundances and ratios of U, Th and K determined by gamma-ray spectroscopy Gamma-ray spectroscopic (U, Th and K) and XRF analyses (As, Ba) are helpful to distinguishU-bearing light-colorea sandstones from U-barren light-colored ones and red sandstones(red claystone) from light-colored sandstones. Therefore, the favorable target area forprospecting the sandstone-type uranium deposits can be defined in northern SichuanProvince.展开更多
With the extended petroleum exploration of the carbonate reservoir in the Longwangmiao Formation,Lower Cambrian in Sichuan basin,looking for a new favorable exploration area is the primary task in current exploration....With the extended petroleum exploration of the carbonate reservoir in the Longwangmiao Formation,Lower Cambrian in Sichuan basin,looking for a new favorable exploration area is the primary task in current exploration.This paper focusing on the dolomite reservoir in the Longwangmiao Formation in the Northern Sichuan basin,will evaluate the reservoir conditions,including reservoir lithology,reservoir spaces,physical properties and other basic characteristics.Combined with sedimentary environment study and diagenesis analysis,the genetic mechanism of Longwangmiao reservoir in study area will be discussed.It indicates that the reservoir rocks of Longwangmiao Formation in the study area are composed of dolarenite and crystalline dolomite,and the main reservoir spaces are intergranular dissolved pores,intragranular dissolved pores and intercrystalline dissolved pores.However,most of dissolved pores have been filled with bitumen,which lead to the reservoir properties very poor,both the porosity and permeability are worse than that of central Sichuan basin,so the reservoir in the Longwangmiao Formation in the Northern Sichuan basin is low-porosity and low-permeability reservoir.During the Early Cambrian Longwangmiao period,the study was near the old-land,and the energy of sea water was not enough to deposit many grain shoals,which cause the sediments are small with lots of quartz and muds.Moreover,because lacking of large scale karstification in the late diagenesis,there isn't much dissolved pores and vugs develop in the Longwangmiao Formation.Some Intergranular dissolved pores and intercrystalline dissolved pores formed by the early atmosphere water dissolved exist as some reservoir spaces,but most of them have been filled with bitumen,which was residual when the ancient oil reservoir transformed.Above factors cause the Longwangmiao Formation in the Northern Sichuan basin become not a very favorable reservoir in Sichuan basin.展开更多
基金the National Natural Science Foundation of China(Grant No.40672143,40472107 and 40172076)the National Major Fundamental Research and Development Project(Grant No.2005CB422107 and G1999043305)+1 种基金Development Foundation of Key Laboratory for Hydrocarbon Accumulation of the Education Ministry(Grant No.2003-01)Project of Southern Exploration and Development Division Company,SINOPEC(2003-04).
文摘The Triassic Jialingjiang Formation and Leikoupo Formation are characterized by thick salt layers. Three tectono-stratigraphic sequences can be identified according to detachment layers of Lower-Middle Triassic salt beds in the northern Sichuan Basin, i.e. the sub-salt sequence composed of Sinian to the Lower Triassic Feixianguan Formation, the salt sequence of the Lower Triassic Jialingjiang Formation and Mid-Triassic Leikoupou Formation, and the supra-salt sequence composed of continental clastics of the Upper-Triassic Xujiahe Formation, Jurassic and Cretaceous. A series of specific structural styles, such as intensively deformed belt of basement-involved imbricated thrust belt, basement-involved and salt-detached superimposed deformed belt, buried salt-related detached belt, duplex, piling triangle zone and pop-up, developed in the northern Sichuan Basin. The relatively thin salt beds, associated with the structural deformation of the northern Sichuan Basin, might act as a large decollement layer. The deformation mechanisms in the northern Sichuan Basin included regional compression and shortening, plastic flow and detachment, tectonic upwelling and erosion, gravitational sliding and spreading. The source rocks in the northern Sichuan Basin are strata underlying the salt layer, such as the Cambrian, Silurian and Permian. The structural deformation related to the Triassic salt controlled the styles of traps for hydrocarbon. The formation and development of hydrocarbon traps in the northern Sichuan Basin might have a bearing upon the Lower-Middle Triassic salt sequences which were favorable to the hydrocarbon accumulation and preservation. The salt layers in the Lower-Middle Triassic formed the main cap rocks and are favorable for the accumulation and preservation of hydrocarbon.
基金Supported by the China National Science and Technology Major Project(2017ZX05001001-002)
文摘This study investigated the characteristics and genesis of reservoirs in the 2^(nd) and 4^(th) members of Sinian Dengying Formation in northern Sichuan and its surrounding areas, on the basis of outcrop, drilling cores and thin section observation and geochemical analysis. The reservoirs of 2^(nd) member are distributed in the middle part of the stratum. The reservoir quality is controlled by supergene karst and the distribution of mound-shoal complex. The bedded elongated isolated algal framework solution-cave and the residual "grape-lace" cave, which are partially filled with multi-stage dolosparite, constituted the main reservoir space of the 2^(nd) member. There is no asphalt distribution in the pores. The pore connectivity is poor, and the porosity and permeability of the reservoir is relatively low. The reservoirs of 4^(th) member were distributed in the upper and top part of the stratum. The reservoir quality is controlled by burial dissolution and the distribution of mound-shoal complex. The bedded algal framework solution-pores or caves, intercrystalline pores and intercrystalline dissolved pores constituted the main reservoir space of the 4^(th) member. It's partially filled with asphalt and quartz, without any dolosparite fillings in the pores and caves. The pore connectivity is good. Most of the 4^(th) member reservoirs had medium-low porosity and low permeability, and, locally, medium-high porosity and medium permeability. Affected by the development of mound-shoal complex and heterogeneous dissolution, the platform margin along Ningqiang, Guangyuan, Jiange and Langzhong is the most favorable region for reservoir development. Deep buried Dengying Formation in the guangyuan and langzhong areas should be the most important hydrocarbon target for the future exploration.
文摘Described in detail in this paper are the geochemical charederistics of thesandstone-type urboum deposits in northern Sichuan Province. Favoable and unfavor-able conditions for the enrichment of uranium are explored on the basis of the elementalabundances and ratios of U, Th and K determined by gamma-ray spectroscopy Gamma-ray spectroscopic (U, Th and K) and XRF analyses (As, Ba) are helpful to distinguishU-bearing light-colorea sandstones from U-barren light-colored ones and red sandstones(red claystone) from light-colored sandstones. Therefore, the favorable target area forprospecting the sandstone-type uranium deposits can be defined in northern SichuanProvince.
基金This research was supported by scientific research starting project of SWPU(No.2017QHZ005)open fund of Shandong Provincial key laboratory of Depositional mineralization(No.DMsMzO1TO35)。
文摘With the extended petroleum exploration of the carbonate reservoir in the Longwangmiao Formation,Lower Cambrian in Sichuan basin,looking for a new favorable exploration area is the primary task in current exploration.This paper focusing on the dolomite reservoir in the Longwangmiao Formation in the Northern Sichuan basin,will evaluate the reservoir conditions,including reservoir lithology,reservoir spaces,physical properties and other basic characteristics.Combined with sedimentary environment study and diagenesis analysis,the genetic mechanism of Longwangmiao reservoir in study area will be discussed.It indicates that the reservoir rocks of Longwangmiao Formation in the study area are composed of dolarenite and crystalline dolomite,and the main reservoir spaces are intergranular dissolved pores,intragranular dissolved pores and intercrystalline dissolved pores.However,most of dissolved pores have been filled with bitumen,which lead to the reservoir properties very poor,both the porosity and permeability are worse than that of central Sichuan basin,so the reservoir in the Longwangmiao Formation in the Northern Sichuan basin is low-porosity and low-permeability reservoir.During the Early Cambrian Longwangmiao period,the study was near the old-land,and the energy of sea water was not enough to deposit many grain shoals,which cause the sediments are small with lots of quartz and muds.Moreover,because lacking of large scale karstification in the late diagenesis,there isn't much dissolved pores and vugs develop in the Longwangmiao Formation.Some Intergranular dissolved pores and intercrystalline dissolved pores formed by the early atmosphere water dissolved exist as some reservoir spaces,but most of them have been filled with bitumen,which was residual when the ancient oil reservoir transformed.Above factors cause the Longwangmiao Formation in the Northern Sichuan basin become not a very favorable reservoir in Sichuan basin.
