Experiment research on anti-swelling agent in water injection exploitation in Hong 1 Well Area

To prevent the reservoir clay swelling which caused by water injection was essential in the process of water injection exploita-tion. According to the study on reservoir bed rocks of Hong 1 well area in Subei Basin, the water sensitive index is 0.43 and critical mineral salt concentration is 6 000 mg/L, it assumed as follows:medium-high water sensitivity, shortage of energe in reservoir bed, low pressure in oil measures, the formation water of Hong 1 formation is CaCl₂ with the total mineral concentration of 111 643.71 mg/L. Combined with proposed injection of sweeping fluid, the anti-swelling rate among three types of anti-swelling agents under different temperatures was studied. It suggested that while the concentration of 1# anti-swelling agent was 1.5%, the anti-swelling rate could be up to 88%, so 1# anti-swelling agent was used in Hong 1 well area.