Application of Retarded Acid Acidizing Technology in Thick Glutenite Reservoirs

In viewing of the development characteristics at the super-high water cut stage in the thick glutenite reservoirs of Shuanghe oilfield, the small treatment radius of conventional acidizing and the poor reacidizing effects, HS-12 retarded acid system, with organic acid and fluorine as its main components, is developed. The subsidiary mechanical subdivision acidizing technology and temporary plugging technology are also developed. Laboratory experiments show that the acid system with excellent retarding properties is highly effective in corroding oil layer detritus of Henan oilfield. The effective functioning period is long, the residual acid does not cause secondary sedimentation damage, and core permeability can be two times higher than that before treatment. Field application in 34 wells in Henan oilfield within 3 years give out a success rate of 90% and remarkable stimulation effects in the injection wells.