黔西北地区天然气成藏地质特征

GEOLOGIC CHARACTERISTICS OF NATURAL GAS ACCUMULATIONS IN THE NORTHWEST OF GUIZHOU

王津义 涂伟 曾华盛 潘文蕾 武蔚文

Wang Jinyi Tu Wei Zeng Huasheng Pan Wenlei Wu Weiwen

中国石油化工股份有限公司, 石油勘探开发研究院, 无锡石油地质研究所, 江苏, 无锡, 214151 2. 长江大学, 石油资源与地球物理学院, 湖北, 荆州, 434023

Wuxi Research Institute of Petroleum Geology, Research Institute of Petroleum Exploration and Production, SINOPEC, Wuxi, Jiangsu 214151, China 2. School of Petroleum Resources and Geophysics, Changjiang University, Jinzhou, Hubei 434023, China

黔西北地区是下寒武统牛蹄塘组、下志留统龙马溪组、上震旦统陡山沱组烃源岩主要发育分布区。对关岭、织金珠藏、金沙岩孔等3个地区烃源岩演化史研究表明,金沙岩孔地区油气生成演化速度慢,成油期持续时间长,干酪根充分降解,对油气生成十分有利,证实黔西北地区具备良好的油气生成条件。黔西北地区主体构造是在以黔中隆起为主导的古构造作用控制下演变和发展的,油气成藏以近源成藏为主,靠近生油中心的黔中隆起是油气运聚的有利区带,古隆起提供的大型岩性—构造复合圈闭是油气富集的主要场所。加里东末期抬升剥蚀使早期油气藏被改造或破坏,燕山期后构造运动是造成早期油气藏破坏与保存的关键因素。因此,保存条件是本区晚期油气成藏的关键。据钻井资料揭示,黔西北地区寒武—志留系压力系统仍然存在,现今仍可能有保存完好的油气单元。

The northwest of Guizhou is the main generation and distribution region for Lower Cambrian Niutitang Formation,Lower Silurian Longmaxi Formation and Upper Sinian Doushantuo Formation source rocks.Studies of source rock evolution histories in Guanling County,Zhuzang Town of Zhijin County and Yankong Town of Jinsha County have indicated that,petroleum generates and evolves slowly in Yankong Town and kerogen is degradated completely,which is favorable for hydrocarbon generation.Tectonic evolutions in the northwest of Guizhou are controlled by ancient tectonic effects leading by Middle Guizhou Uplift.Hydrocarbons mainly accumulate around source rocks.Middle Guizhou Uplift near petroleum generation center is favorable for petroleum migration and accumulation.Large lithologic and tectonic traps provided by ancient uplifts are main locations for oil and gas pools.Uprises and erosions in late Caledonian destroy early pools.Tectonic movements after Yanshanian are the keys for pool destroy and preservation.Cambrian and Silurian pressure system still exist in the northwest of Guizhou,where petroleum units may still exist.

中国石油化工股份有限公司科技项目(P04038)

https://doi.org/10.11781/sysydz200805445