黑墩油田芦草沟组裂缝油藏储层应力敏感性评价

STRESS SENSITIVITY EVALUATION OF THE LUCAOGOU FRACTURE RESERVOIR IN HE[DUN OILFIELD

三塘湖盆地主要的生油凹陷是马朗凹陷,主力油层在二叠系芦草沟组。储层基岩基本无渗透性,裂缝为其主要的储集空间和渗流通道,黑墩油田二叠系芦草沟组油藏裂缝特征最为突出。裂缝性油藏与孔隙性油藏及双重介质性油藏应力敏感性差异很大。在黑墩油田储层物性特征研究的基础上,对应力敏感性机理做了分析,通过应力敏感实验,获得了应力敏感曲线和应力敏感滞后曲线,经评价黑墩油田应力敏感性强,滞后效应较弱。在二叠系芦草沟组裂缝性油田开发过程中油层保护应以裂缝性油藏为主,油田注水开发可以在一次采油后期进行。

The main oil-generating sag in Santanghu basin is Malang sag, and main pay zone Permian Lucaogou formation. The reservoir matrix is not permeable essentially, where fracture is the main storage space and drainage channel. The characteristics of fracture reservoir of the Permian Lucaogou formation in Heidun oilfield show the best. There are marked differences in stress sensitivity between fracture reservoir, porous reservoir and fracture-porous reservoir. Stress sensitivity mechanism was analyzed based on the reservoir physical property study of Heidun oilfield. The stress sensitivity curve and stress sensitivity lag curve were achieved by stress sensitivity experiments. There were strong stress sensitivity and faint lag effect in Heidun oilfield according to evaluation. The pay zone protection should give priority to the fracture reservoir in development of Permian lucaogou formation. Waterflooding can begin at the end of primary recovery phase.