塔中隆起F21断裂带油气成藏过程与多相态成因

Hydrocarbon Accumulation Process and Multiphase Formation in the F21 Strike-slip Fault Zone of Tazhong Uplift

熊昶 赵星星 吴江勇 张新樵 汪鹏

XIONGChang ZHAOXingxing WUJiangyong ZHANGXinqiao WANGPeng

中国石油塔里木油田公司, 新疆 库尔勒 841000 中国石油天然气集团有限公司超深层复杂油气藏勘探开发技术研发中心, 新疆 库尔勒 841000

Tarim Oilfield Company, PetroChina, Korla, Xinjiang 841000, China R & D Center for Ultra-deep Complex Reservoir Exploration and Development, CNPC, Korla, Xinjiang 841000, China

针对塔中隆起F$_{\rm{{Ⅱ}}}$21断裂带奥陶系油气藏相态分布复杂问题，基于构造解析、地球化学的综合分析认为，原油密度、天然气干燥系数及气油比等参数的平面分布趋势与走滑断裂分段构造密切相关，翼尾构造带北部发育凝析气藏，南部依次发育挥发性油藏与原油油藏。F$_{\rm{{Ⅱ}}}$21断裂带与北部拗陷富满、顺北地区原油生源相同，主要来源于下寒武统烃源岩。原油成熟度沿断裂带由北至南依次降低，断裂带北部主要为原油裂解气，中部与南部主要为干酪根裂解气。F$_{\rm{{Ⅱ}}}$21断裂带经历多期油气充注，翼尾地堑部位为油气有利充注点，喜马拉雅期盐下原油裂解气的强烈充注改造是北部凝析气藏形成的重要原因，受古构造影响，晚加里东期与晚海西期生成的原油资源主要于翼尾地堑构造南部鼻状隆起区域聚集成藏。

Aiming at the complicated phase distribution of Ordovician reservoirs in Fault F$_{\rm{{Ⅱ}}}$21 of Tazhong Uplift, we make a comprehensive analysis of tectonic analytical geochemistry, and find out that the plane distribution of oil and gas physical properties such as oil density, gas drying coefficient, gas oil ratio, etc. is closely related to strike-slip fault segment structure, that condensate gas reservoir develops in the north of the wing tail structure zone, and that volatile oil reservoir and crude oil reservoir develop successively in the south area. The crude oil in the F$_{\rm{{Ⅱ}}}$21 fault is the same as that of the northern depression Fuman and Shunbei areas, mainly from Lower Cambrian source rocks. The maturity of crude oil decreases from north to south along the fault zone. Natural gas in the north of the fault zone is mainly crude oil cracking gas, and in the central and southern parts mainly kerogen cracking gas. The Ordovician reservoir in the F$_{\rm{{Ⅱ}}}$21 fault zone underwent multi-stage oil and gas injection, and the wing tail graben site was a favorable filling point for oil and gas, and the strong charging and transformation of pre-salt crude oil cracking gas in the Himalayan period was an important reason for the formation of condensate gas reservoir in the northern part of the fault zone. Affected by the paleostructural, the oil resources generated in the Late Caledonian and Late Hercynian periods were mainly accumulated in the southern nose uplift area of the wing tail graben structure.

10.11885/j.issn.1674-5086.2024.02.29.06