论文部分内容阅读
鄂尔多斯盆地苏里格地区中二叠统石盒子组盒8下亚段砂岩属于低渗储层,因此在气藏开发时存在潜在的应力敏感性损害。通过对该区苏10井、苏11井和苏16井77个岩心样品采用围压升高—降低的方法进行应力敏感性实验,发现储层应力敏感性中—较强,非储层应力敏感性强。在结合前期对储层样品进行薄片、储集性能等的研究后,发现Ⅰ类、Ⅱ类储层砂岩,特别是其中含高岭石的岩屑石英砂岩在净围压为2 MPa时的渗透率较高,这类砂岩粒度多较粗,柔性岩屑含量较少,残余粒间孔隙和粒径较粗的高岭石晶间孔隙保存较好,在升压—降压过程中岩石受压力影响较小,因此表现出应力敏感性较弱,反之则较强。
Sandstone in the lower sub-stage 8 of the Middle Permian Shifangzi Formation in the Sulige area of the Ordos Basin belongs to a low-permeability reservoir, so potential stress-sensitivity damage exists during gas reservoir development. Through stress sensitivity experiments on 77 core samples of Su 10 well, Su 11 well and Su 16 well in this area, the stress sensitivity experiments were carried out by using confining pressure increasing-decreasing method. It is found that medium- Strong. After studying the samples and reservoirs in the early stage, we found that the permeability of Class Ⅰ and Ⅱ sandstones, especially kaolinite-bearing lithic quartz sandstones at a net confining pressure of 2 MPa The higher the sandstone size, the more coarse the sandstone is, the smaller the amount of the soft lithic debris is, the better the preservation of pore space between the residual intergranular pores and the coarse-grained kaolinite is, and the pressure of the rock under the step-up- Less affected, thus showing a less sensitive to stress and vice versa.