重复压裂技术在江汉低渗透油田的应用

Application of Re-fracturing Technology in Low-permeability Oilfield of Jianghan

初次支撑裂缝和天然裂缝的应力场分布,以及生产活动引起的孔隙压力变化,导致了井眼附近应力的变化,决定了重复压裂裂缝是否能重新定向。重复压裂选井选层至关重要,其中剩余可采储量和地层能量是重复压裂取得增油效果的前提。适合于江汉低渗透油田重复压裂主要工艺措施有:加大施工规模、提高施工砂比,选用比初次压裂强度高、导流能力好的支撑剂等。

The stress field distribution of first-support fracture and natural fracture as well as the pore pressure change caused by production result in the stress change near the borehole, which determines whether the duplicate fracture can be reoriented. The key to re-fracture is well and layer selection, in which remaining recoverable reserves and strata energy are a prerequisite for the effect of increasing oil by re--fracturing. The main technology and measures to fit low--permeability oilfields of Jianghan include increasing the scale of construction, improving construction sand ratio, and selecting the propping agent which has higher strength and better conductivity than that used in the initial fracturing.