Although the stress sensitivity of carbonate reservoir has been investigated extensively, that of saline-lacustrine fractured tight carbonate reservoir still remains to be fully understood. In this work, permeability stress sensitivity behavior of saline-lacustrine fractured tight carbonate reservoir was investigated based on steady state test and pressure attenuation method. Several core analysis and time-dependent deformation experiments were adopted to reveal the factors and mechanisms of stress sensitivity. Experimental results showed that pressure attenuation method could be available for stress-sensitivity assessment of tight carbonate reservoirs. Rock permeability decreased with increasing in effective stress, which could be classified into three stages: rapid decline, moderate decline and stable-slight decline stage. Fractures had a strong stress sensitivity behavior and higher permeability recovery rate after stress unloading, showing the stronger elastic deformation, while tight matrix showed the opposite results with stronger plastic deformation. The increase in number of nano-intercrystal pores led to stronger stress sensitivity behavior. The relationship between the stress sensitivity and mineral type was qualitatively built, and stress sensitivity of carbonate reservoir was positively related to the content of dolomite, salt minerals and clays, and negatively related to the content of quartz and calcite. The time-dependent deformation of salt minerals strengthened the stress sensitivity of saline-lacustrine tight carbonate reservoir.

尽管已经对碳酸盐岩储层的应力敏感性进行了广泛研究，但盐湖相裂缝致密碳酸盐岩储层的应力敏感性仍有待充分理解。在这项工作中，基于稳态试验和压力衰减方法研究了盐湖相裂缝性致密碳酸盐岩储层的渗透应力敏感性行为。通过几个岩心分析和时变实验，揭示了应力敏感性的影响因素和机理。实验结果表明，压力衰减方法可用于致密碳酸盐岩储层的应力敏感性评价。岩石渗透率随有效应力的增加而减小，可分为三个阶段：快速下降，中度下降和轻度稳定下降。应力卸载后，断裂具有很强的应力敏感性行为和较高的渗透率恢复率，表现出更强的弹性变形，而紧密的基体则表现出相反的结果，塑性变形更强。纳米晶间孔数量的增加导致更强的应力敏感性行为。定性建立了应力敏感性与矿物类型的关系，碳酸盐岩储层的应力敏感性与白云岩，盐矿物和粘土的含量呈正相关，与石英和方解石的含量呈负相关。盐矿物随时间的变形增强了盐湖相致密碳酸盐岩储层的应力敏感性。表现出更强的弹性变形，而紧密的基体则表现出相反的结果，塑性变形更强。纳米晶间孔数量的增加导致更强的应力敏感性行为。定性建立了应力敏感性与矿物类型的关系，碳酸盐岩储层的应力敏感性与白云岩，盐矿物和粘土的含量呈正相关，与石英和方解石的含量呈负相关。盐矿物的时变变形增强了盐湖相致密碳酸盐岩储层的应力敏感性。表现出更强的弹性变形，而紧密的基体则表现出相反的结果，塑性变形更强。纳米晶间孔数量的增加导致更强的应力敏感性行为。定性建立了应力敏感性与矿物类型的关系，碳酸盐岩储层的应力敏感性与白云岩，盐矿物和粘土的含量呈正相关，与石英和方解石的含量呈负相关。盐矿物随时间的变形增强了盐湖相致密碳酸盐岩储层的应力敏感性。定性建立了应力敏感性与矿物类型的关系，碳酸盐岩储层的应力敏感性与白云岩，盐矿物和粘土的含量呈正相关，与石英和方解石的含量呈负相关。盐矿物随时间的变形增强了盐湖相致密碳酸盐岩储层的应力敏感性。定性建立了应力敏感性与矿物类型的关系，碳酸盐岩储层的应力敏感性与白云岩，盐矿物和粘土的含量呈正相关，与石英和方解石的含量呈负相关。盐矿物随时间的变形增强了盐湖相致密碳酸盐岩储层的应力敏感性。