A NOVEL TEMPERATURE-RESISTANT WATER-BASEDPOLYMER GEL SYSTEMAND EVALUATION OFWELLBORE GAS CHANNELING PERFORMANCE

摘要

According to the severe gas channeling of shale gas, CO2, and nitrogen in the drilling process of low- permeability reservoirs or gas flooding process, A water-based sulfonated polyacrylamide polymer CT gel system suitable for high-temperature reservoirs was prepared for the conditions of the borehole wallin low-permeability reservoirs. The influence of wa-ter-based polymer mass fraction, system temperature, system pressure and initial permeability on the core plugging rate of the gel system was explored. Studiesshowed that the core plugging rate of the CT gel sys- tem at 30 MPa, 100°C, 0.35 CT content and 1.8 mL.s' is 98.4, which is much higher than the 78.3 of the commercially available polymer system. The increase of system temperature and initial permea- bility caused the decrease of the core plugging rateof the gel system, and the core plugging rate of the gel system increased with the increase of system pressure and sulfonated polyacrylamide content. Among the four factors, the system pressure and sys-tem temperature have little effect on the core plug- ging rate of the gel system, while the sulfonated pol-yacrylamide content is the biggest factor that signif- icantly improves the core plugging rate and wellbore gas channeling prevention. The improvement of gas channeling and the temperature resistance of water- based gel systems has important practical signifi- cance.