高盐油藏水驱开发盐析伤害表征方法

Characterization method of salting?鄄out damage by water flooding in high?鄄salt reservoir

李南 田虓丰 任仲瑛 谭先红 张利军 彭世强1

中海油研究总院有限责任公司开发研究院，北京 100027 中国石油集团工程技术研究院有限公司北京石油机械有限公司，北京 102206

Development Research Department of CNOOC Research Institute Co., Ltd., Beijing 100027, China Beijing Petroleum Machinery Co., Ltd., CNPC Engineering Technology R&D Company Limited, Beijing 102206, China

通过对比不同地层水矿化度、不同压力下岩心渗透率的变化，初步认识了高盐油藏水驱开发机理，形成此类油藏水驱开发地层压力与渗透率保持率关系图版和盐析时机判断图版，从而有效量化盐析对储层渗透率造成的伤害，实现了盐析对储层渗透率伤害的动态表征。研究结果表明：相同的储层渗透率，地层水矿化度越高，储层盐析后渗透率保持率越低；而相同的地层水矿化度，储层渗透率越高，储层盐析后渗透率保持率越高。驱替压力越低，出现盐析的时机越早，最终的渗透率保持率也越低；在相同驱替压力下，渗透率与渗透率保持率呈正相关。通过验证发现，盐析伤害表征方法的预测结果与实际动态非常接近，研究成果对高盐油藏的合理开发具有指导意义。

By comparing the changes of core permeability under different formation water salinity and pressure, the mechanism of water flooding in high?鄄salt reservoirs is preliminarily understood. The relationship between formation pressure and permeability retention in water flooding development of this kind of reservoir and the judgment chart of salting-out time are formed. Based on this achievement, we can effectively quantify the damage caused by salting-out to reservoir permeability and realize the dynamic characterization of the damage caused by salting out. The results show that with the same reservoir permeability, the higher the salinity of formation water, the lower the permeability retention of reservoir after salting out is; with the same salinity of formation water, the higher the permeability of reservoir, the higher the permeability retention of reservoir after salting out; the lower the displacement pressure, the earlier the salting out, and the lower the ultimate permeability retention. Under the same displacement pressure, permeability is positively correlated with permeability retention. Through verification, it is found that the prediction results of salting-out damage characterization method in this paper are very close to the actual dynamic. This study will have a certain guiding significance for the rational development of high-salt reservoirs.

10.6056/dkyqt201906013