Damage Preventative Completion Fluid for Sandstone Geothermal Reservoir

The development and utilization of geothermal resources in China is at a rapid stage of development, with the development and utilization of geothermal resources in sandstone thermal reservoirs of medium and low temperatures as the main. However, during the development of geothermal resources, due to the special geological structure of loose sandstone thermal reservoir, during the drilling and completion process, the reservoir sand production is serious, and the drilling and completion fluid is easy to enter the reservoir to cause sensitivity damage, as well as the problem that the solid substances in the drilling and completion fluid block the reservoir and cause the reservoir permeability to drop. In order to solve the above problems, this study introduced the key treatment agents, such as bionic wall fixative, stealth acid PF-HTA and corrosion inhibitor, and optimized the dosage through experiments. Finally, the polymer film stealth acid completion fluid system was formed. Laboratory research shows that the completion fluid system has a large permeability recovery value after polluting the reservoir core, good compatibility with drilling fluid, little damage to the reservoir, and good reservoir protection effect.