低渗透油藏老井侧钻技术研究与应用

低渗透油藏具有典型的低渗、低压,非均质性强和天然微裂缝发育特征。油藏经注水补充能量开发后开发矛盾突出,导致高含水井或水淹井比例增多和油藏采出程度低,严重影响了整体开发效果。鉴于目前针对高含水井或水淹井治理难度大的问题,立足低渗透油藏开发特征,在明确了水驱后剩余油分布规律和调研了512″套管井开窗侧钻技术现状的基础上,提出了利用大斜度井分段压裂改造提高剩余油动用程度的技术思路。针对侧钻井改造技术难点,对储层改造工艺技术进行了筛选和优化,在实现分段压裂改造提高储层泄流面积的同时,有效降低了施工安全风险。为提高暂堵压裂效果,并配套研发了耐压性高和稳定性强的关键性堵剂。现场试验表明,采用老井侧钻方式改造效果显著,是开展低渗透油藏水淹井治理的有效手段之一,为后续提高油藏开发效果具有一定的借鉴意义。

Study and application of sidetracking technology for old wells in the low-permeability reservoir

Low permeability reservoirs is a typical low permeability,low productivity ,strong heterogeneity and natural micro-fractures reservoir. It is gradually predominant for the development contradiction in the reservoir developed by injecting water to replenish energy to cause a high proportion of high water cut oil wells and a low recovery percent , which can influence the overall development result seriously. Given the current problem about solving the high water cut oil wells or flooded wells, a method of multi-stage fracturing technique in highly deviated wells ,which is based on the development characteristics , is brought forward to improve the degree of utilization of the remaining oil by familiar with the distribution of the remaining oil in the water flooding reservoir and the technology status of sidetracking about the 5 ? "cased hole. Stimulation technology were screened and optimized for the fracturing difficulties about sidetracking to achieve segmentation fracturing, improve reservoir drainage area and reduce the risk of construction. The key material, which is superior for thermal stability and resistance to pressure, was developed to improve the effect of the temporal-blocked fracturing. Field test showed that sidetracking technology for old wells is one of the effective means to solve the problem of flooded wells and provide guidance for improving reservoir development.