济阳坳陷上古生界煤成气成藏规律认识

Gas accumulation analysis of upper Paleozoic coal in Jiyang depression

通过对济阳坳陷已知气藏类型分析,指出了济阳坳陷煤成气藏的主要控制因素是沉积埋藏史,同时考虑构造变动、储集条件、保存条件及圈闭的完整性等因素,将济阳坳陷源自上古生界石炭—二叠系的油气藏划分成两大类六类成藏模式。其中济阳坳陷较为重要的成藏模式类型包括中坳新坳间断式成烃成藏模式、中坳新隆间断式成烃成藏模式和中隆新坳间断式成烃成藏模式。各种成烃成藏模式具有不同的特点,其勘探目的层系和资源潜力也有所不同,尤以中坳新坳型成藏模式最为有利,例如惠民凹陷南坡、沾化凹陷孤西断裂带等。

Based on the analysis of known gas pools in Jiyang depression, it is pointed out that the sediment-burial history is the critical factor for the formation of coal-formed gas pool. The pool formation types can be divided into two categories and six sub-categories according to sediment-burial history and other factors such as tectonic movement, reservoir conditions, reservation conditions and integrity of trap. Among these gas pool formation types there are three types which are very important in Jiyang depression, i.e., Mesozoic era subsidence-Cenozoic era subsidence model; Mesozoic era subsidence-Cenozoic era swell model and Mesozoic era swell-Cenozoic era subsidence model. Every model has different character and its exploration goal and resource potential are variable. The most favorable model is Mesozoic era subsidence-Cenozoic era subsidence, such as south slope of Huimin sag and Guxi fault belt of Zhanhua sag.