高含盐油藏储层参数变化微观实验研究

Micro Experiment Research on the Change of Saliferous Reservoir Parameters

用微观实验方法研究高含盐油藏水驱储层参数变化的规律与机理.采用真实岩心制作而成的微观孔隙模型进行水驱实验,研究了驱替速率、含盐量、岩心渗透率、注入水性质、驱替孔隙体积倍数等因素对储层参数变化的影响,并且对实验模型进行跟踪摄像,建立了高含盐油藏的动态地质模型.实验结果表明:水驱后渗透率有增有减,与普通砂岩油藏相比,渗透率变化有明显的滞后现象,孔隙度变化都呈增加趋势;水驱过程中存在微粒运移的现象.盐的溶解是储层参数变化的根本原因;作为胶结物形式存在的可溶性盐的溶解,造成了岩石颗粒的脱落和运移,它是储层参数变化的直接原因.

The dynamic geological model of saliferous reservoir was built with the micro experiment applied to studying the changing law and mechanism of formation parameters in saliferous reservoir during water flooding. The water flooding experiment was carried out with the micro pore model made of the real core. The effects of such factors as displacement rate, salinity, permeability, water quality, pore volume of displacement, ere, on the change of reservoir parameters were studied, and the experiment was traced continuously with photography. The results show that the permeability after water flooding can increase or decrease and there are exist obvious hysteresis in the change of permeability compared with the common sandstone reservoir. The porosity presents the increasing trend in this process. There exists migration of micro particles in the process of water flooding. The solution of salt existing as the cement results in the escape and migration of particles, which is the immediate cause leading to the change of reservoir parameters.