关键词: 强水敏致密砾岩, 压裂液侵入, 液阻伤害, 物性, 岩性, 黏土矿物含量, 岩心驱替实验, 核磁共振实验, 定量预测模型

Abstract: The distance and influencing factors of fluid resistance damage in strong water sensitive tight glutenite reservoirs，as well as the reservoir damage pattern after fracturing fluid invasion，were simulated and studied through a combined measurement method of long core，conventional core displacement experiments，and nuclear magnetic resonance. Based on the experiment，a multivariate nonlinear regression prediction model was established to quantitatively predict the degree of fluid resistance damage. The results show that： （1）Reservoir properties play a decisive role in the distance of liquid resistance damage. The lower the permeability，the smaller the distance of liquid resistance damage，and the more likely it is to cause reservoir damage. When the permeability is the same，gravel bearing coarse sandstone cores are more prone to liquid resistance damage than gravel bearing fine sandstone cores，but the difference is small. After fracturing fluid invades the formation，it has obvious“three zones”characteristics，such as“pressing into the liquid resistance zone”， “imbibition resistance zone”，and“original stratigraphic zone”. And“pressing into the liquid resistance zone”is the main factor controlling the degree of liquid resistance damage.（2）The physical properties，lithology，and content of expansive clay minerals together constitute threshold that determines the variability of liquid resistance damage in tight conglomerate reservoirs. The lower the permeability of similar multimodal sandstone cores，the closer the variability threshold of liquid resistance damage is near 1. The initial liquid resistance damage rate of bimodal gravel coarse sandstone cores is higher，which is relieved after soaking，and the initial damage rate of bimodal gravel fine sandstone cores is lower，which increases after soaking. The damage rate of cores with higher clay mineral content tends to shift towards 1.（3）The accuracy of the established multiple nonlinear regression prediction model for the degree of liquid resistance damage and porosity，permeability，and clay mineral content is greater than 80%，this model can be used for quantitative prediction of the degree of liquid resistance damage in oilfield exploration and development processes when there is a lack of core samples or when indoor displacement simulation experiments are difficult to conduct.

Key words: strong water sensitive dense conglomerate, fracturing fluid intrusion, fluid resistance damage, physical properties, lithology, content of clay minerals, core displacement experiments, nuclear magnetic resonance test, quantitative prediction model