CO2泡沫压裂优化设计技术及应用

针对苏里格低压、低渗透气藏常规水基压裂液压后返排困难,导致储层水锁伤害的问题,研究利用CO2泡沫压裂来降低压裂液滤失,提高压裂液返排率,降低对储层的伤害。有针对性地研究了CO2泡沫压裂优化设计技术,包括:CO2泡沫压裂起泡技术、酸性交联技术、变泡沫质量和恒定内相设计技术等。现场应用表明,长庆苏里格气田气藏应用CO2泡沫压裂技术,可大大提高返排率,缩短压裂液返排时间,降低压裂液对气层的伤害,提高压裂效果。

Optimizing Design Technology and Application of CO2 Foam Fracturing

To reduce frac fluid loss and formation damage and promote frac fluid flowback, Hydraulic fracturing with hydrocarbon dioxide foam was used in Sulige, low pressure and low permeability gas reservoir, to decrease the problem of frac fluid flow back and formation damage caused by conventional water based frac fluid. Hydraulic fracturing techniques with hydrocarbon dioxide foam was studied in the paper. These techniques include foam bubbling, acidic cross-linking, variable foam quality and constant internal phase etc. Through practical application, it showed that it could remarkably improve fluid flow back and frac effect, reduce the duration of flow back and formation damage.