Talking about several methods of plugging the tubing of oil-water wells under pressure

Working under pressure mainly refers to the operation in the wellbore with professional equipment and tools under pressure at the wellhead of oil, gas and water wells. Its main function is not to pollute the formation and not to change the current formation pressure. In actual work, affected by the scaling (wax) of the original well tubing string, the inner diameter of the tubing became smaller, resulting in the plugging of the plugging device in most cases, or even the plugging tool cannot be used at all. In some wells, after plugging plugs were in place, the packers on the original well string could not be unblocked, the plugs could not be salvaged or the success rate of salvage was low, which made the subsequent workover more difficult. How to apply the current process technology to meet the needs of workover, talk about a few methods