Experimental study and economic evaluation of low temperature drying treatment of abandoned water-based drilling fluid

Abandoned water-based drilling fluids are the waste of oil drilling engineering operations. It will not only keep the cost of drilling fluid high, but also have a very adverse impact on the environment if it is directly discharged. Reusing of abandoned water-based drilling fluid after low-temperature drying treatment is one of treatment methods which is economic and conforms to the modern development trend. In this paper, the experimental study and economic evaluation of the low-temperature drying technology of polymer drilling fluid system, sulfonated drilling fluid system and Sichuan shale gas well drilling fluid system were conducted. The results show that the performance of polymer drilling fluid deteriorates seriously after being dried at 120℃, and decreasing the drying temperature can reduce the deterioration, but the performance of the sulfonated drilling fluid system and the drilling fluid system from 2 shale gas wells in Sichuan remained basically unchanged at 120℃. This shows that the low-temperature drying technology can recycle some abandoned water-based drilling fluid, and the processing cost is low, the solid matter after treatment is convenient for storage and transportation, and the drilling fluid cost can be greatly reduced. At the same time, it can also reduce the amount of waste drilling fluid emissions and reduce the risk of environmental pollution in oil drilling engineering.