基于触变性浆体的双液法堵漏研究

Research on dual liquid plugging method based on thixotropic slurry

摘要:

针对钻井过程中裂缝型、溶洞型等严重漏失问题，提出双液法堵漏。具体是将两种或多种不同性质的流体同时注入井筒，利用混合后流体产生的触变性达到封堵漏层的一种新型堵漏技术。为了研究混合流体的堵漏性能，从而获得最佳堵漏配方，室内采用有机凝胶溶液配置水泥浆，并与坂土浆按不同比例混合，采用滞后环法测得混合浆体的触变性能以评价其堵漏性能。结果表明：有机凝胶加量为0.08%（与水泥质量比）时，有机凝胶溶液制备的水泥浆与0.25%浓度的坂土浆以10∶1.8的比例混合后，浆体具有最好的堵漏性能，且固化后的抗压强度能满足现场施工要求。现场应用表明利用有机凝胶溶液制备的水泥浆与坂土浆组合堵漏效果良好。

Abstract:

Aiming at serious leakage problems such as crack type and karst cave type， a dual liquid method is proposed for plugging. Specifically， it is a new type of plugging technology that injects two or more fluids with different properties into the wellbore at the same time， and uses the thixotropy generated by the mixed fluid to seal the lost circulation layer. In order to study the plugging performance of mixed fluid and obtain the best plugging formula， organic gel solution is used to prepare cement slurry indoors， and mixed with Bantu slurry in different proportions. The thixotropy of mixed slurry is measured by hysteresis loop method to evaluate its plugging performance. The results show that when the dosage of organic gel is 0.08% bwoc， the cement slurry prepared by organic gel solution and 0.25% Bantu slurry are mixed at a ratio of 10∶1.8， the slurry has the best plugging performance， and the compressive strength after curing can meet the requirements of on-site construction. Field application shows that the combination of cement slurry prepared with organic gel solution and bentonite slurry has good plugging effect.