苏里格气田钻井液回收再利用技术

苏里格气田地质施工条件满足钻井液工艺共通性,符合钻井液回收再利用工艺,分析了可再利用的GWSSL钻井液体系特点。采用现场3口井水平段不同时期钻井液取样以及实验室新配浆,结合现场施工周期特点,评价了钻井液在储备15 d过程中的性能变化情况。结果表明,完钻钻井液若处理剂使用量充足,维护处理到位,在15d的储存、倒运、再利用预设周期内,钻井液常规性能与完钻时基本保持一致,可利用成分所占比例高,且即使流变性出现变化,滤失量及膨润土含量在合理范围内,可用于稀释配浆改型。预计回收再利用1 m3完钻钻井液,理论上可减少成本约300元。钻井液回收再利用技术需配合使用好固控设备,保证完钻钻井液的品质,并配合KPAM等抑制性絮凝剂的改型、维护,否则低密度固相的污染将影响钻井液性能的可控,甚至导致井下复杂。

Recycling of Drilling Fluids in Sulige Gasfield

Geological condition of the formations in Sulige Gasfield allows the use of drilling fluids with same formulation and properties, making possible the recycling of drilling fluid in multiple-well drilling. GWSSL is such a drilling fluid that can be reused in this area. Samples of drill-in fluids in horizontal drilling from 3 wells at different times and fresh drilling fluid made in laboratory were tested for their property changes over a period of 15 days. The test results showed that, given enough treatment of the drilling fluids with necessary additives, in 15 days, which was mandatory for the drilling fluid to be stored, transported, and reused, the samples had properties that were almost the same as that of the drilling fluid at well completion. Most of the drill-in fluid can be reused, some of them may need slight treatment, for example, dilution. It is estimated that recycling of 1 m3 drilling fluid would save 300 RMB Yuan. Using solids-control equipment to remove the unwanted solids, combined with treatment of the drilling fluids with high molecular weight flocculant, such as KPAM, the properties of the recycled drilling fluids will be easy to control.