柳北低渗区注水井压裂增注技术

Fracturing technology of intensified water injection wells in low permeability areas of Liubei Oilfield

针对柳北低渗区油藏强水敏、强应力敏感性、塑性特点,在对储层进行系统分析研究的基础上,进行了注水井压裂技术及双元黏土防膨压裂液体系研究。该技术使用保护储层的酸性黏土稳定剂复合黏土防膨剂,防止黏土膨胀、扩散和运移带来的伤害。考虑塑性地层对有效支撑裂缝的影响,优化了裂缝长度及加砂强度。利用水井返排控制优化技术,消除应力敏感性对增注效果的影响,从而减小了施工规模,降低了施工成本,提高了水井压裂施工效果。该技术在柳北低渗区的应用,获得了明显的增注效果。

The oil reservoir in low permeability areas of Liubei Oilfield features in strong water sensitivity, strong stress sensitivity, and plastic properties. Based on systematic research and analysis of reservoirs, this paper studies the injection well fracturing technology and the dual anti-swelling fracturing fluid system. The technology combines the clay stabilizers of acid properties used for protecting reservoirs with the inhibitors for anti-swelling of clay to prevent the hazards caused by swell, diffusion, and migration of clay. Taking the effect of plastic formations on effectively propping fractures into account, the length of fractures and the quality of sand absorbed are optimized. Based on using the optimal injection well control technology, the effect of stress sensitivity on intensified injection is removed. Therefore, the construction scale is decreased, the construction cost is reduced, and the fracturing treatment of injection wells is enhanced. The technology has been applied to the low permeability areas of Liubei Oilfield, which achieves good intensified injection results.