低渗透油藏小井距开发试验研究

Development of low permeability reservoir with closely-spaced wells

克拉玛依油田八区下乌尔禾组油藏为低孔、特低渗透、带裂缝的厚层块状砾岩油藏。采用数值模拟方法开展了小井距开发层系划分与组合优化研究及井网和裂缝合理配置研究。确定了最佳层系组合方式,层系含水75％为最佳上返时机。合理开发方式为注水井排与裂缝方向平行的线状注水方式,裂缝穿透率应控制在40％左右,注水井排采油井含水80％时为最佳转注时机。小井距试验方案实施后,油藏开发效果明显改善,预计可提高采收率11.78％。

The fractured thick-bed clumpy conglomerate reservoir of Wuerhe Formation in Block 8 of Keramay Oilfield is characterized by low porosity and super-low permeability. The research on development layer division and combination, and on the reasonable relationship between the well pattern and fractures, is carried out by numerical simulation for closely-spaced well pattern development of the reservoir. The optimum layer combination is determined with the best opportunity for the upward movement of producing layer set to be at the watercut point of 75%. The linear waterflooding pattern, with the injector array parallel to the fractures, is most desirable for the reservoir development and the fracture penetration coefficient should be controlled by around 40%. The best conversion opportunity is at the watercut point of 80%. The closely-spaced well development scenario demonstrates production expectations after implement, the recovery will be enhanced by 11.78%, and thus provides a successful example for similar reservoirs.