A geological feature in the Qaidam Basin known as the"Shell Bar"contains millions of freshwater articulated clam shells buried in-situ.Since the 1980s this feature in the now hyper-arid basin has been interp...A geological feature in the Qaidam Basin known as the"Shell Bar"contains millions of freshwater articulated clam shells buried in-situ.Since the 1980s this feature in the now hyper-arid basin has been interpreted to be lake deposits that provide evidence for a warmer and more humid climate than present during late Marine Isotope Stage 3(MIS 3)(Bowler et al.,1986).However,the global climate during展开更多
The GOI（grains containing oil inclusions） index is used to distinguish oil zones,oil-water zones and water zones in sandstone oil reservoirs.However,this method cannot be directly applied to carbonate rocks that may...The GOI（grains containing oil inclusions） index is used to distinguish oil zones,oil-water zones and water zones in sandstone oil reservoirs.However,this method cannot be directly applied to carbonate rocks that may not have clear granular textures.In this paper we propose the Effective Grid Containing Oil Inclusions（EGOI） method for carbonate reservoirs.A microscopic view under10× ocular and 10 x objective is divided into 10×10 grids,each with an area of 0.0625 mm×0.0625 mm.An effective grid is defined as one that is cut（touched） by a stylolite,a healed fracture,a vein,or a pore-filling material.EGOI is defined as the number of effective grids containing oil inclusions divided by the total number of effective grids multiplied by 100%.Based on data from the Tarim Basin,the EGOI values indicative of the paleo-oil zones,oil-water zones,and water zones are 〉5%,1%-5%,and 〈1%,respectively.However,the oil zones in young reservoirs（charged in the Himalayan） generally have lower EGOI values,typically 3%-5%.展开更多
The Silurian hydrocarbon exploration in the northwest Tarim Basin had long been fruitless, till Well XSD1 drilled in 2018 in the Shajingzi structural belt, northwest Tarim Basin tapped industrial gas flow from the Sil...The Silurian hydrocarbon exploration in the northwest Tarim Basin had long been fruitless, till Well XSD1 drilled in 2018 in the Shajingzi structural belt, northwest Tarim Basin tapped industrial gas flow from the Silurian for the first time. The reservoir-forming model and resource extent need to be made clear urgently. Based on the comprehensive research of drilling,formation testing, geochemical data, and sedimentary and accumulation history, in combination with field surveys, experiments, structure interpretation and reconstruction of structure evolution, it is found that:(1) The northwest Tarim Basin had widespread tidal deltaic deposits in the Silurian period, which contain good reservoir-cap combinations;(2) the Shajingzi fault and associated faults connected the Cambrian-Ordovician source rocks in the Awati sag, and controlled the formation of Silurian structural traps, hence, the traps turned up along the structural belt in an orderly pattern and came together into contiguous tracts;(3) the Silurian petroleum in Shajingzi structural belt was dominated by gas, and the major accumulation period was the Himalayan period when the traps fixed in shape;(4) the Silurian gas resources in the Shajingzi belt were estimated at around 2.018×10^(11)m^(3), and Silurian gas resources of the northwest Tarim Basin were estimated at 2.03×10^(12)m^(3), implying huge exploration potential, so this area will become a major area for reserve and production increase from clastic strata in the basin;(5) with the Shajingzi fault of large scale and long active time connecting deep source rock layers, multiple formations in Lower Paleozoic of Shajingzi structural belt may have breakthroughs in hydrocarbon exploration.展开更多
文摘A geological feature in the Qaidam Basin known as the"Shell Bar"contains millions of freshwater articulated clam shells buried in-situ.Since the 1980s this feature in the now hyper-arid basin has been interpreted to be lake deposits that provide evidence for a warmer and more humid climate than present during late Marine Isotope Stage 3(MIS 3)(Bowler et al.,1986).However,the global climate during
基金supported by the project of Research on Fluid Inclusions and Geological Ages of Hydrocarbon Accumulations of Key Reservoirs in the Tarim Basin (No.041014080008)
文摘The GOI（grains containing oil inclusions） index is used to distinguish oil zones,oil-water zones and water zones in sandstone oil reservoirs.However,this method cannot be directly applied to carbonate rocks that may not have clear granular textures.In this paper we propose the Effective Grid Containing Oil Inclusions（EGOI） method for carbonate reservoirs.A microscopic view under10× ocular and 10 x objective is divided into 10×10 grids,each with an area of 0.0625 mm×0.0625 mm.An effective grid is defined as one that is cut（touched） by a stylolite,a healed fracture,a vein,or a pore-filling material.EGOI is defined as the number of effective grids containing oil inclusions divided by the total number of effective grids multiplied by 100%.Based on data from the Tarim Basin,the EGOI values indicative of the paleo-oil zones,oil-water zones,and water zones are 〉5%,1%-5%,and 〈1%,respectively.However,the oil zones in young reservoirs（charged in the Himalayan） generally have lower EGOI values,typically 3%-5%.
基金Supported by the China Geological Survey Project (DD20190106,DD20190090)。
文摘The Silurian hydrocarbon exploration in the northwest Tarim Basin had long been fruitless, till Well XSD1 drilled in 2018 in the Shajingzi structural belt, northwest Tarim Basin tapped industrial gas flow from the Silurian for the first time. The reservoir-forming model and resource extent need to be made clear urgently. Based on the comprehensive research of drilling,formation testing, geochemical data, and sedimentary and accumulation history, in combination with field surveys, experiments, structure interpretation and reconstruction of structure evolution, it is found that:(1) The northwest Tarim Basin had widespread tidal deltaic deposits in the Silurian period, which contain good reservoir-cap combinations;(2) the Shajingzi fault and associated faults connected the Cambrian-Ordovician source rocks in the Awati sag, and controlled the formation of Silurian structural traps, hence, the traps turned up along the structural belt in an orderly pattern and came together into contiguous tracts;(3) the Silurian petroleum in Shajingzi structural belt was dominated by gas, and the major accumulation period was the Himalayan period when the traps fixed in shape;(4) the Silurian gas resources in the Shajingzi belt were estimated at around 2.018×10^(11)m^(3), and Silurian gas resources of the northwest Tarim Basin were estimated at 2.03×10^(12)m^(3), implying huge exploration potential, so this area will become a major area for reserve and production increase from clastic strata in the basin;(5) with the Shajingzi fault of large scale and long active time connecting deep source rock layers, multiple formations in Lower Paleozoic of Shajingzi structural belt may have breakthroughs in hydrocarbon exploration.
