姬塬油田长4+5砂岩储层微裂缝与水驱油特征

目的对鄂尔多斯盆地姬塬油田长4 5砂岩储层微裂缝与水驱油特征进行综合研究。方法在研究区评价井、探井、生产井动态资料解释的基础上,通过岩心观察、薄片分析、真实砂岩微观模型水驱油实验的方法分析裂缝与水驱油特征。结果姬塬油田长4 5储层岩性主要为岩屑长石砂岩,岩屑平均含量17.1%;几乎在所有的岩石碎屑集合体中均发育有微裂缝,微裂缝的发育受控于3种因素:三角洲古坡度、成岩过程中的差异压实作用和构造运动。结论长4 5储层基质孔隙主要通过岩屑中的微裂缝相互连通,两者之间构成良好的网络连通系统;储层中微裂缝对储集空间的贡献作用不大,微裂缝能够降低注水压力,对于连通基质孔隙、提高储层的渗流能力起到重要的作用。

Characteristics of micro-fracture and water-flooding in Chang 4+5 sandstones reservoir of Jiyuan Oilfieid

Aim The multidisciplinary analysis on characteristics of micro-fracture and water-flooding in Chang 4 5 sandstones reservoir of Jiyuan Oilfield.Methods Rely on dynamic data of exploration wells,producible wells,appraisal wells,and use methods of core observation,thin section analysis,experiment of authentic sandstone micro model.Results The Chang 4 5 reservoir rock of Jiyuan Oilfield is mainly lithic arkose with average rock fragment content of 17.89%.Micro-fracture is well developed in rock fragments aggregation.Three controlling factors of micro-fracture well developed is delta slope,differential comparison during diagenetic process and tectonic movements.Conclusion Micro-fractures mostly found in rock fragments connect each other through matrix pore.The micro-fracture and reservoir matrix pore compose a net-model seepage system with good performance.Micro-fracture can reduce the injection pressure,improve the connect ability between the micro-fracture and pore,and enhance the seepage ability in the reservoir rock.