Experimental investigation of changes in petrophysical properties and structural deformation of carbonate reservoirs

• 作者: KAZEMZADEH Ezatallah MAJDI Abbas MORADZADEH Ali POURAFSHARY Peyman SALIMIDELSHAD Yaser
• 来源期刊: 石油勘探与开发:英文版
• 学科: 工学
• 关键词: CYCLIC pressure loading petrophysical PROPERTY CARBONATE reservoir CT SCAN rock physical PROPERTY structure deformation
• 年，卷（期）: 2019,（3）
• 页码范围: 565-575
• 页数: 11页
• 分类号: TE

摘要

To examine the effect of pressure on pore structure and petrophysical properties of carbonate rock, the porosity, permeability, CT scanning, SEM and elastic wave velocity of two carbonate core plug samples from an oilfield in Southwest Iran were analyzed under cyclic pressure. One of the plugs was calcite and the other was dolomite with anhydrite nodules. The cyclic pressure exerted on the samples increased from 13.79 MPa to 27.58 MPa in six steps, and the variations in petrophysical properties of the two samples at different pressure loading and unloading steps were counted and analyzed. The results show that the calcite sample decreases in porosity and permeability with the increase of pressure, which is consistent with the results from compression and shear wave velocity tests. In the dolomite sample, the decreasing trend was not observed;fluctuations of compressive and shear velocities were observed during the loading stage, which may be due to different geometries of the pores and the porosity variation in the sample. Understanding the variation of carbonate petrophysical properties with pressure is helpful for optimizing reservoir development scheme.