碳酸盐岩应力敏感性对有效应力作用时间的响应  

RESPONSES OF CARBONATITE STRESS SENSITIVITY TO LOADING TIME UNDER EFFECTIVE PRESSURE

作　　者：王业众[1] 康毅力[1] 张浩[1] 游利军[1] 

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室

出　　处：《钻采工艺》2007年第3期105-107,共3页Drilling & Production Technology

基　　金：中国石油天然气股份有限公司科技风险创新研究项目;四川省青年科技基金项目资助;编号:02ZQ026-042

摘　　要：有效应力作用时间是影响岩石孔隙结构变形的重要因素。然而前人的研究鲜有提及有效应力作用时间对应力敏感性的影响。文章以某典型碳酸盐岩油气藏为研究对象,开展考虑有效应力作用时间的应力敏感性实验,并与常规实验结果进行了对比。结果表明,随有效应力作用时间的增加,岩样渗透率降低,且裂缝岩样较基块岩样渗透率降低幅度明显,2h基块岩样降低3%～5%,裂缝岩样降低4%～10%;与常规实验相比,考虑时间因素的基块和裂缝岩样应力敏感程度分别增加一个等级。分析认为,在有效应力长时间作用下岩样发生弹-塑性形变,孔喉及裂隙缩小幅度更加显著,导致渗透率进一步降低,应力敏感程度增强。The loading time under effective stress is an important factor that influences the deformation of rock’s pore structure. But there is little study on the influence of time on stress sensitivity. The experiments of stress sensitivity taking loading time under effective stress into account are conducted, and the results were compared with that of conventional experiments. It is showed that with the increase of the loading time under effective stress, the permeability of core samples curves cut down, and that the decreasing extent of fractured core samples is greater than that of matrix core samples. Within two hours, the permeability of matrix core samples reduces by 3~5 percent, and that of fractured core samples reduces by 4~10 percent. By contrasting,the stress sensitivity of matrix and fractured core samples taking into account loading time under effective stress are stronger than that of regular matrix and fractured core samples. The stress sensitivity increased one grade respectively. It is analyzed that core samples produce elastic-plastic strain under long time effective stress, the pores and cracks are reduced in large extent, which causes the permeability to decrease and the stress sensitivity to strengthen.

关 键 词：应力敏感 有效应力 时间 碳酸盐岩 弹-塑性形变 

分 类 号：P618.13[天文地球—矿床学]