巴什托普构造-岩性超高压油藏油水倒置成因

针对塔里木盆地巴什托普油田生屑灰岩段钻井揭示出的油水倒置现象,应用油井动态生产资料和流体性质的对比研究,分析油藏的流体连通性;通过岩心和薄片观察,查清储集层岩石学特征。研究油藏流体的异常高压成因,探索油气运移和超压的关系,最终建立新的油藏模式。指出,在调整中的油藏内部,是小型超压单元和物性致密带克服油水驱替压力,阻碍油气向斜坡高部位运移,形成"油水倒置"。并提出在麦盖提西部非构造油气勘探方向的和领域。

Origin of Oil/Water Inversion in Structural-Lithologic Overpressure Reservoir in Bashituopu Oilfield, Tarim Basin

The oil/water inversion phenomenon has been revealed by recent well drilling aimed at the Carboniferous bioclastic limestone in Bashituopu oilfield in Tarim basin.To interpret the abnormal phenomenon,the fluid connectivity in this reservoir is analyzed by well perfomance and production data and fluid property correlation,and the petrological characteristic of the reservoir is investigated by core and thin-section observation.And then the reservoir model is developed by research of its abnormal pressure genesis and relations between oil-gas migration and overpressure.It is suggested that in inner regulation of reservoir,it is the mini-overpressure unit and tight zone that overcome the oil-water displacement pressure and block the oil-gas migration toward the top of slope,hence forming the phenomenon of oil/water inversion.Also,the direction and domain of the non-structural oil-gas prospecting in western Maigaiti slope are presented in this paper.