Energy Reports (Nov 2021)
Core-nano-emulsion used in the laboratory study of plugging micro–nano cracks in southwestern Tarim
Abstract
The southwestern Tarim area is rich in oil and gas resources and has good exploration and development potential. However, due to the widespread occurrence of micro–nano cracks and pore leakage during the drilling process, it is difficult to solve the problem, resulting in the loss of drilling fluid and the swelling of clay minerals as the filtrate enters the pore throat. This has severely restricted the exploration and development process of oil and gas resources in this area. In order to improve the complexity and frequency of southwestern Tajikistan, this article analyzes the development of wellbore formation fractures in this area, and on this basis, through comparison and screening, the drilling fluid core-nano-emulsion independently developed by the University of China. Finally, use the core-nano-emulsion for drilling fluid independently developed by China University of Petroleum (Beijing). This new material is a nano-emulsion with nano-SiO2 as the core, and its D50 is about 100 nm. Experiments show that by adding 5% nano-core emulsion for optimization, the water loss of the drilling fluid under high temperature and high pressure is 4 ml, and the thickness of the mud cake is 1.5 mm. The pressure conduction method was used to evaluate the plugging performance of the micro–nanopore cracks, and the results showed that the optimized pressure was reduced by 0.337 Mpa compared with the optimized pressure. Practice has proved that the inner core nanoemulsion can be used as an additive for water-based drilling fluids to realize the optimization of drilling fluids.
