小拐油田二叠系佳木河组储层裂缝发育特征

Development Characteristic of Reservoir Fractures in Jiamuhe Formation of Xiaoguai Oilfield

小拐油田佳木河组储层主要发育微裂缝、高角度张开缝、高角度充填缝、直立缝、砾缘缝等,其中以未充填的直立缝最为发育,为主要裂缝类型。裂缝发育方位为近EW向和近SN向,其中近EW向裂缝占绝对优势,与现今最大主应力方向基本一致,有效性好。裂缝发育的主控因素主要为岩性和厚度,构造部位对裂缝发育程度影响不明显。裂缝综合预测结果表明,好的裂缝发育区位于距离红车断裂带稍远的拐102井—拐5井—拐105井区、拐103井—车排3井—拐9井—车502井—车501井一带,较好的裂缝发育区位于裂缝发育区周围,呈环带状分布,包括红车断裂带附近的拐11井—拐147井—拐101井—拐104井地区以及拐106井区。

Reservoir fractures in Jiamuhe Formation of Xiaoguai Oilfield have important influence on accumulation and productivity of oil and gas. This oilfield has micro-fractures, high-angle open fractures, high angle filled fractures, vertical fractures and gravel edge fractures. Vertical unfilled fractures develop best among them, which is the key types of fractures. The main orientation of fractures lies in nearly E-W and nearly S-N. Nearly E-W orientation fractures are dominant fractures, which is better validity because of its consistence with the direction of the recent maximum principal stress. The dominant factors of the fractures development mainly include rock types and rock stratum. The tectonic position plays less apparent effect on the fracture development. The comprehensive prediction result of fractures shows that developed zone of fractures lies in the well area of Guai102-GuaiS-Guai105, Guai103-Chepai3-Guai9-Che502-Che501, which is a far Hongche fault belts. Relative developed zone of fractures shows a zonal distribution around the developed zone of fractures, including the well area of Guail-Guai147-Guai101-Guai104 and Guai106.