哈南阿尔善油藏微裂缝特征及其对开发的影响

CHARACTERISTICS OF MICRO-FRACTURES AND THEIR INFLUENCE ON WATERFLOODING IN AERSHAN RESERVOIR, HANAN OILFIELD

张莉 杨亚娟 岳乐平 苗坤 宋社民 张满库

Zhang Li Yang Yajuan Yue Leping Miao Kun Song Shemin Zhang Manku

哈南油田阿尔善储层发育构造微裂缝.经显微镜薄片观察,微裂缝的开度区间为10～30μm,延伸长度为 l～3 mm,面积密度为每平方毫米0025 mm.微裂缝是大裂缝的前奏,大裂缝发育区也是微裂缝发育区,微裂缝发育受控于断裂构造,与断裂及大裂缝同向,以NE向为主.经模型观察,双重孔隙介质模型的水驱油方式为裂缝-部分基质孔隙驱油.微裂缝对开发具有双重作用,一方面微裂缝可以改善基质渗流能力,另一方面微裂缝与大裂缝、断层形成断裂网络,对汪水产生不利影响.针对这一特点,在微裂缝发育区域,应采用周期性注水以期提高驱油效果.

Structural fractures developed well in Aershan reservoir, Hanan Oilfield. The width of the micro-fractures is 10～30 pin, the length is 1～3 mm and surface density is 0.025 mm. The micro-fracture porosity and permeability have been calculated, and the distribution is analyzed. Micro-fractures are preface of macrn-fractures and the macro-fracture developed areas are also micro-fracture developed areas. A sandstone micro-model experiment has been done to investigate the process of displacement between fractures and matrix. Based on the above studies, micro-fractures play two different roles on waterflooding. On one hand, they may improve the permeability of the reservoirs; on the other hand, the together with macro-fractures and faults may improve network, which have bad effect on waterflooding. According to the characteristics of,micro-fractures in Aershan reservoir, some suggestions such as periodic injection are put forward to improve the effect of waterflodding in fracture-developed areas.

10.11743/ogg20010216