陕甘宁盆地川口油田低渗透油藏长6油层裂缝特征

通过对野外野头观测，岩心观察，薄片鉴定、地层倾角测井解释等方法，对川口油田长6油层裂缝进行了研究，川口油田长6油层主层裂缝方向为近EW向，天然显裂缝规模小且不发育，裂缝在原始地层条件下多为闭合状态，只有在人工激发后才会表现出明显的裂缝特征，川口油田储层类型为孔隙型储集层，该区油层埋深500－700m，垂向应力为最小主应力，压裂后理论上应产生水平缝，但受到天然垂直（闭合）缝的影响，在裂缝发育区可能会形成垂直压裂缝，在目前注水条件下，注水实验区储层裂缝的作用还未表现出来。

Characteristics of fractures of Chang-6 low-permeability reservoir,in Chuankou oil field,Shan-Gan-Ning basin

Fractures of Chang 6 reservoir in Chuankou oil field are studied by use of the data of the outcrop,cores,slices and the dip log Main fractures,extending along the direction of near EW,are small in size and poor developed Most fractures are closed underground and will show the characteristics of open fractures by artificial excitation So Chang 6 1 belongs to porosity reservoir Chang 6 1 reservoir is 500~700 m in depth The minimum stress is vertical,and theoretically the hydraulic fracture should be horizontal However, in fracture developed areas,the hydraulic fractures may be vertical for the effect of natural fractures Fractures have not shown the effect on the waterflooding by now