水平气井支撑剂回流机理及防砂工艺研究

Study on proppant flowback mechanism and sand control technology of horizontal gas wells

随着水平井分段压裂工艺水平的提高,水平井分段压裂规模逐渐增大,水平井压后排液时间长,支撑剂回流现象严重,支撑剂回流将刺坏地面流程设备,并降低压裂改造效果。通过支撑剂受力情况和力矩分析,建立了支撑剂回流临界返排流速模型,并阐述了支撑剂回流机理。针对影响支撑剂回流的因素,川西气田在水平气井采取了微过量顶替、尾追纤维、控制压后返排速度、压裂液快速破胶等工艺措施,有效地防止了水平气井支撑剂回流。

With the improvement of staged fracturing technology of horizontal wells, its scale increases gradually. After fracturing, the clean-up time is long and the proppant flowback phenomenon is serious. Proppant flowback will stab surface process equip- ments and reduce the reformation effects of fracturing. Through the analysis of stress and torque of proppant, this paper established the critical flowback rate model and elaborated the mechanism. Aiming at the influencing factors of proppant flowback, the applica- tion of the technical measures including micro-excess replacement, chase fiber, flowback rate control and rapid gel breaking of fracturing fluids has effectively prevented proppant flowback in horizontal wells of West Sichuan gas field.