埕岛东部潜山油气成藏分析

Analysis of hydrocarbon accumulation of buried hill in east Chengdao area

针对埕岛东部潜山地质格局及油气成藏规律比较复杂、成藏特征认识不够深入等问题,通过对钻井、录井、构造解释及测试资料等的综合分析,研究其构造及地层特征,对其油气分布规律及成藏主控因素进行深入探讨。结果表明,受多期强烈构造运动的影响,研究区地层分布非常复杂,不同构造带或同一构造带不同构造部位的地层发育均存在差异。纵向上,埕岛东部潜山在太古界、下古生界、上古生界和中生界均有不同程度的油气富集,其中以下古生界最为富集,且主要分布于构造较高部位; 平面上,由构造主体向翼部,油气分布层位由老到新,油气藏类型由断块—残丘型油气藏向地层不整合油气藏过渡。通过对典型井的解剖,认为储盖组合和侧向封堵条件为研究区油气成藏的主控因素,由此建立埕岛东部潜山的油气成藏模式。

In accordance with complicated geological framework and hydrocarbon accumulation rules and insufficient understanding for reservoir characteristic, comprehensive analysis of drilling, borehole logging, structure interpretation and testing data was put forward to study its structure and strata characteristics, petroleum distribution rules and master control factors for hydrocarbon accumulation. Result shows that the strata of research area are distributed irregularly as the result of multiphase tectonic movement and rollover. Strata in different structural zone or different place of the same structural zone have deviation. There is variable degree of petroleum enrichment in Archean, lower Paleozoic, upper Paleozoic, and Mesozoic along the vertical section. Lower Paleozoic has the most enrichment and petroleum mainly accumulates in high part of structure. Along the horizontal section, oil distribution horizon varies from older to newer and oil reservoir styles varies from fault block and residual hill to disconformity crossing the structural main part to the limb. Dissection of typical wells shows that the reservoir-cap relationship and lateral sealing condition are main control factors of hydrocarbon accumulation, and the hydrocarbon accumulation mode is herein constructed.