水平缝大规模压裂技术研究及应用——以萨北开发区北部过渡带为例

Research and Application of Large-scale Fracturing Technology for Horizontal Fractures--A Case Study of Northern Transitional Zone in Sabei Development Area

大庆长垣萨北开发区北部过渡带储层原油具有含蜡量高、含胶量高、黏度高的特点,窄小河道发育,水驱控制程度和多向连通比例较低,常规压裂效果差,采出程度低。针对以上情况,结合水平缝大规模压裂工艺原理进行了萨北开发区北部过渡带加大压裂规模的可行性论证。通过理论公式及数值模拟成果确定了最佳穿透比范围;通过室内实验对压裂液体系配方进行了优选,确定了适应萨北开发区北部过渡带油层条件的低伤害压裂液体系。以优化设计参数为基础,并结合现场施工方案的制订和实施,实施后平均单井日产液量是改造前的3.05倍,日产油量是改造前的4.4倍,解决了水驱控制程度低的问题,取得了较好的增油效果。水平缝大规模压裂为萨北开发区北部过渡带剩余油挖潜提供了新的技术支持。

The crude oil in the reservoirs of northem transitional zone of Sabei development area of Dlaqing placanticline features in high paraffin content,high gel content and high viscosity,small channel development in sand body,poor waterflooding control effect and low multi-directional connection proportion.It was difficult for conventional fracturing to get good results and favorable recovery production.In view of the problems mentioned above,the feasibility on enlarging fracturing scale in northern transitional zone of Sabei development area was discussed by combining the large-scale fracturing principle for horizontal fractures.The optimal penetration ratio was confirmed through the theoretical equation and numerical simulation results.Through the lab experiment,the formula of fracturing fluid system was optimized to determine the low-damage fracturing fluid system applicable for oil reservoirs in northern transitional zone.Furthermore,the optimal design parameters were applied for formulation and implementation of on-site schemes.Average daily liquid production per well was 3.05 times and daily oil production was 4.4 times higher than that before treatment.The problem of poor waterflooding control effect was hence solved and oil production was increased remarkably.I arge-scale fracturing technology for horizontal fractures provided a new technical support for remaining oil exploitation in the northern transitional zone of Sabei development area.