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.