深水救援井连通压裂液性能研究

Study on Properties of Connecting Fracturing Fluid of Deepwater Relief Wells

救援井与事故井不能成功交会时,采用压裂的方法使两口井连通时所用到的压裂液即为连通压裂液。深水压裂作业的一个主要的问题是在不超过地面设备压力极限的条件下提供足够的井底造缝压力。要解决该问题,可以采用对压裂液进行加重的方法。研究针对深水救援井连通压裂的施工需要,室内优选设计了一种适合深水救援井连通压裂的压裂液基本配方:淡水+0.4%VIS+0.4%SWQ+3%KCl+0.05%PAM+98%NaBr(配方百分数为质量分数),并对压裂液的加重性能、耐温性能、低温流变稳定性、耐剪切性能以及降阻性能进行了评价。研究表明,该压裂液体系可加重至1.5g/cm3,耐温可达140℃,并具有较好的耐剪切性能、降阻性能,能够满足深水救援井连通压裂的需要。

When relief well could not converge with failure well,fracturing had to be used to connect the two wells,the fracturing fluid used to connect the 2wells was called connecting fracturing fluid.The main problem for deepwater fracturing was to provide enough fracturing pressure not exceeded pressure limit of the surface equipment.The problem could be solved by weighting the fracturing fluid.A connecting fracturing fluid was designed according to the needs of deepwater relief well and the basic formula was as follows:Fresh water+0.4%VIS+0.4%SWQ+3%KCl+0.05%PAM+98%NaBr.The properties of its weighting,temperature resistance,low temperature rheology,endurance of shearing and friction reduction of the fluid were evaluated.The test results show that the density of fracturing fluid can reach 1.5g/cm3and its temperature resistance is up to 140℃.And it has good endurance of shearing and friction reducing ability,it can meet the needs of deepwater fracturing of relief wells.