Both the XWD1 and XWD2 wells drilled in 2017 in the Wensu salient, northwest Tarim Basin have achieved high-yield industrial oil flow. Based on the comprehensive research on drilling, oil testing, geochemistry and log...Both the XWD1 and XWD2 wells drilled in 2017 in the Wensu salient, northwest Tarim Basin have achieved high-yield industrial oil flow. Based on the comprehensive research on drilling, oil testing, geochemistry and logging data, in combination with the field surveys, 2 D seismic data processing and interpretation as well as sedimentation and accumulation history comparison, we carefully compared the source conditions, migration channels, reservoir-cap distribution and trapping types in the Wensu salient, and subsequently constructed a reservoir-forming pattern. Though the Wensu salient is lack of source rocks, some drainage systems were widely developed and efficiently connected to adjacent fertile depressions. Due to the moderate Miocene paleogeomorphic conditions in the Wensu salient, the delta and shore-shallow lacustrine beach bar sandy bodies were developed within the Jidike formation, and consequently form widely distributed structural-lithologic traps. The hydrocarbon generation, migration and accumulation mainly happened in the Neogene-Quaternary period, which suggests that the reservoir-forming pattern should be characterized as late-period and compound accumulation. It suggests that, although the border belts in the Tarim Basin might be short of source rocks and structural traps, they are potential to accumulate hydrocarbon in a large scale; the description of efficient hydrocarbon migration channels and structural-lithologic traps is crucial for any successful exploration.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
基金Supported by China Geological Survey Projects(DD20160203,DD20189602,DD20160169)
文摘Both the XWD1 and XWD2 wells drilled in 2017 in the Wensu salient, northwest Tarim Basin have achieved high-yield industrial oil flow. Based on the comprehensive research on drilling, oil testing, geochemistry and logging data, in combination with the field surveys, 2 D seismic data processing and interpretation as well as sedimentation and accumulation history comparison, we carefully compared the source conditions, migration channels, reservoir-cap distribution and trapping types in the Wensu salient, and subsequently constructed a reservoir-forming pattern. Though the Wensu salient is lack of source rocks, some drainage systems were widely developed and efficiently connected to adjacent fertile depressions. Due to the moderate Miocene paleogeomorphic conditions in the Wensu salient, the delta and shore-shallow lacustrine beach bar sandy bodies were developed within the Jidike formation, and consequently form widely distributed structural-lithologic traps. The hydrocarbon generation, migration and accumulation mainly happened in the Neogene-Quaternary period, which suggests that the reservoir-forming pattern should be characterized as late-period and compound accumulation. It suggests that, although the border belts in the Tarim Basin might be short of source rocks and structural traps, they are potential to accumulate hydrocarbon in a large scale; the description of efficient hydrocarbon migration channels and structural-lithologic traps is crucial for any successful exploration.
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.
基金the National Natural Science Foundation of China(Nos.42004107,42074165)the Open Research Fund Program of Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University)+1 种基金Ministry of Education,China(No.2019YSJS13)Department of Water Resources of Hunan Province,China(No.XSKJ2019081).
