二元体系与油层渗透率的匹配关系——以克拉玛依油田七中区克拉玛依组下亚组砾岩油藏为例

Investigation on How Binary System Matches with Reservoir Permeability:A Case Study of the Conglomerate Reservoir in Lower Karamay Formation in District Qizhong,Karamay Oilfield

克拉玛依油田七中区油层气测渗透率主要分布在28.8~300.0 mD,渗透率级差大,部分区域存在高渗窜流通道。在二元体系驱先导试验过程中,由于对二元体系与储集层物性的匹配关系认识不清,部分井组油层堵塞,油井产液能力大幅下降,亟需确定二元体系与油层渗透率的匹配关系。针对扩大试验区的油藏特征,利用不同渗透率的岩心开展二元体系注入性实验,根据阻力系数、残余阻力系数和黏度损失率,进行注入性综合评价。结果表明,储集层气测渗透率不大于30.0 mD时,低分子量10~50 mPa·s、中—高分子量10~20 mPa·s的二元体系注入性好;气测渗透率为30.0~100.0 mD时,适合注入低—中分子量10~50 mPa·s、高分子量10~35 mPa·s的二元体系;气测渗透率为100.0~300.0 mD时,低—高分子量10~50 mPa·s的二元体系注入性皆宜。

The reservoir permeability obtained from mud log in District Qizhong of Karamay oilfield is mainly distributed between 28.8 and 300 mD.The permeability contrast is large and channeling is serious in partial zones.Pilot tests on binary flooding found some wells blocked and the production capability reduced greatly,so it was urgent to understand how the binary flooding system can well match with the reservoir properties.Binary flooding experiments were performed on cores with different permeabilities,and the results were evaluated in resistance co⁃efficient,residual resistance coefficient and viscosity loss rate.It is concluded that the binary systems with low or medium to high molecular weight(10-50 mPa·s and 10-20 mPa·s,respectively)are applicable for the reservoirs with the permeability not more than 30.0 mD,and those with low to medium(10-50 mPa·s)and high molecular weight(10-35 mPa·s)are applicable for the reservoir with the permeability of 30.0 to 100.0 mD,and those with low to high molecular weight(10-50 mPa·s)for the reservoir with the permeability of 100.0 to 300.0 mD.