构造活动对雪峰山邻区海相油气分布的控制

在厘定雪峰山活动带大地构造属性的基础上, 据湘鄂西地区和湘中地区原始油气地质条件及后期破坏、 次生成藏特点, 探讨了显生宙以来雪峰山活动带对邻区海相油气分布的构造控制。研究表明： 加里东运动和燕山运动是雪峰山地区最强烈的两期陆内造山事件, 构造变形的区域不均一性导致两侧邻区海相油气地质特征和分布各异。湘鄂西地区下组合震旦系—志留系烃源岩均已高过成熟, 以干气为主, 主要聚集在复向斜内封堵条件好的构造–岩性复合型圈闭内; 而湘中地区海相油气赋存在上组合内, 烃源岩处于成熟—过成熟阶段, 龙潭组煤系盖层以下古背斜及相邻向斜内的次级背斜对油气聚集较为有利。

The Tectonic Controls on the Distribution of Marine Oil and Gas in the AdjacentAreas of Xuefeng Mountain

Based on determining the property of the tectonic activity of the Xuefeng Mountain, according to theoriginal petroleum geology condition, post-destruction of oil and gas and sub-generating characteristics of reser-voirs in western Hunan and Hubei, and central Hunan regions, this paper explores the tectonic controls of XuefengMountain Activities on the distribution of marine oil and gas in adjacent areas. Studies show that the Caledonianmovement and Yansian movement were the most powerful two intracontinental orogenic events in the XuefengMountain region, and the regional disparity of tectonic deformation has led to the differences of geology charac-teristics and distribution of marine oil and gas on both sides. The maturity of source rocks of lower assemblage inwestern Hunan and Hubei provinces are high over-mature, and the component is mainly dry gas, and they mainlygather in structural-lithologic compound traps, where the plugging condition are better in synclinorium. The marineoil and gas of the Hunan regions gather in upper assemblage, and the source rocks are mature-over-mature. Theancient anticline under Longtan Formation coal-bearing cap rock and the sub-anticline within adjacent syncline aremore favorable for oil and gas sub-aggregation.