吐鲁番坳陷地下水动力环境与油气赋存关系

THE RELATION BETWEEN GROUNDWATER DYNAMICS ENVIRONMENT AND HYDROCARBON ENRICHMENT IN TULUFAN DEPRESSION

现代地质理论研究认为,地层水是烃类运移聚集的栽体,油气运聚规律与水动力势场的关系密不可分。吐哈盆地水动力类型为重力流盆地,主要供水区是盆地北部博格达山;区域水头高程呈现北高南低、地层水水势梯度东弱西强的特点,最小水头高程与白垩纪至第四纪沉降中心的迁移相一致,从东向西由红台地区的洼陷中央逐渐过渡到西部的艾丁湖南斜坡;油气富集规律受控与水动力势场及地层水与地表水的交替区带,油气富集区与水动力低势区完全吻合,从东向西,小草湖洼陷分布于东南斜坡区,丘东洼陷富集于南斜坡,胜北洼陷则分布于南部和西南部;油气藏形成后同样受水动力场的影响,油气调整再分配和被地表水驱替而遭破坏。坳陷西南部艾丁湖斜坡区(鲁西低凸起)是水动力低势区,可能是形成岩性地层油气藏的有利场所。

In modern geology, groundwater is the cartier of hydrocarbon migration and accumulation, thus they are inseparably related. The type of groundwater dynamics in Tuha basin is gravity flow, where the main water supply zone is the Bogeda mountain in the north of the basin. Oil enrichment is dominated by groundwater potential field and the alternate zone of surface water and formation water. The oil enrichment zones match the low hydrodynamic potential area exactly. Similarly, hydrodynamic field influences the reservoirs after they were formed, the results of it are the oil and gas adjustment and redistribution, or the damage of some reservoirs caused by surface water displacement. The Aidinghu slope area southwest of the depression, as a low hydrodynamic area, is a promising region for hthologic pinehout reservoirs in future exploration.