鄂尔多斯盆地特低渗透砂岩储层裂缝压力敏感性及其开发意义

The Pressure Sensitivity of Fractures and Its Development Significance for Extra Low-permeability Sandstone Reservoirs in Ordos Basin

为了分析特低渗透砂岩储层高角度裂缝的压力敏感性特征,对鄂尔多斯盆地陇东地区延长组特低渗透砂岩储层基质岩样、含天然裂缝岩样和含人造裂缝岩样进行了对比实验。实验结果表明,特低渗透砂岩储层裂缝的压力敏感性十分明显,在无裂缝时基质岩块为中等程度敏感性,含裂缝时为强压力敏感性。裂缝的开度越大,渗透率越高,其压力敏感性越强,裂缝渗透率的恢复程度越小。裂缝的压力敏感性特征对特低渗透砂岩油藏开发具有十分重要的意义。

In order to analyse the pressure sensitivity feature of high-dip fractures in the extra lowpermeability sandstone reservoirs, the contrast experiment among matrix sample, bearing natural fracture sample and bearing artifieial fracture sample of extra low-permeability reservoirs in Ordos basin was accomplished. The experiment results indicate quite obvious pressure sensitivity feature of fractures in the extra low-permeability reservoirs. The matrix sample without fracture has medium pressure sensitivity and the samples with fractures have strong pressure sensitivity. The biggei the fracture aperture and permeability, the stronger the pressure sensitivity is. The stronger the pressure sensitivity, the lower the resumptive degree of fracture permeability is. The pressure sensitivity of fractures is of great significance to the development of the extra low-permeability sandstone reservoirs.