低渗砂岩油藏压力敏感性实验研究

压力敏感性对低渗透砂岩气藏的损害程度主要由储集层岩石本身的特性所决定。储集层岩石颗粒和胶结物的成分、含量、分布,储集层的孔隙结构和喉道特征等因素都是影响和决定储集层压敏损害大小的内在因素。在研究低渗透砂岩油藏的压力敏感性损害过程中,利用天然岩心进行压力敏感性实验,结果表明,裂缝比孔隙的应力敏感程度要强得多,应力卸载后裂缝的渗透率恢复率不超过27.8%,孔隙性岩样的渗透率恢复率可达到原先的94.8%。并且分析了压力敏感性伤害的原因及其对注采过程的影响。

EXPERIMENTAL STUDY ON PRESSURE SENSITIVITY IN LOW PERMEABILITY SANDSTONE RESERVOIR

One of main damage factors in low-permeability sandstone oil pool is pressure sensitivity, degree of which is dependent on rock's features. The composition, content, distribution of rock particles and cements, pore structure and throat features are all inner factors that affect and determine the size of pressure sensitivity.During the research on pressure sensitivity damage of low-permeability sandstone oil pool, natural cores were used for the experimental analysis of pressure sensitivity, and results indicated that fracture type cores were more sensitive to stress than porous cores. After the stress was unloaded, the permeability of fracture type cores is returned by 27.8%, while the permeability of porous cores is returned by 94.8%. The paper also analyzed the reason of stress sensitivity and its influence on the procedure of injection and production.