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 exploitation.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.