Field application of gas power casing patch technology

As of leakage casing,a new casing patch method-gas power casing patch technology-is developed.The high-temperature and high-pressure gas energy produced from energetic materials works as the power source to propel the relative motion of pistons and piston cylinders.Then the taper sleeves at two ends of the reinforced tubes are kept in relative motion.The process makes metal anchors and metal sealing rings be firmly set on the internal wall of the casing through radial expansion.Finally the reinforced tubes are fixed on the casing deformation and make it be well repaired.This new technology has the following advantages of simple operation and good technical performance as compared to the conventional bellows extension casing technology and the water power casing patch technology.The field application in Yanchang Oilfield shows that the anchorage force of gas power patched casing is more than 800 kN and its pressure endurance is as high as 25 MPa.The casing failure wells are repaired and the perforation intervals are sealed successfully.The gas power casing patch technology fills in the technical gap of repairing casing in China and solves the problems of repairing casing fracture and water plugging at the middle and later stages of oilfield development.