Research on Multi-Layer Drilling Mud Reuse Technology

Addressing the issues of low reuse rates and high waste content of drilling fluids commonly observed in oilfields, research on reuse technology based on utilizing the same system across different sections of the same well has been conducted. Using the F oilfield as a case study, the mechanism of wellbore destabilization was investigated through X-ray diffraction and scanning electron microscopy. Corresponding inhibitory anti-collapse drilling fluids for shallow layers were formulated, and a successful deep drilling fluid formula was developed by adding and replacing chemicals in the base fluid, thereby achieving the reuse of multilayered waste drilling fluids. Indoor evaluation results indicate that the high-temperature rheology of the modified deep drilling fluid is reasonable; the high-temperature inhibitor performs excellently, with a 16-h rolling recovery rate of >= 98%; and the settlement stability is robust, with a settlement ratio of 0.50 after 2 h of resting. These findings demonstrate that the drilling fluid possesses both excellent sand-carrying capacity and strong inhibitory effects, meeting the requirements for rapid drilling and wellbore stabilization in this stratum. This technology is straightforward and easy to implement, and it is expected to reduce treatment costs and promote efficient development within the block.