Application of 3.5-Inch Small-Diameter Well Coiled Tubing Workover Technology in South Sulige

In the middle and late stages of oilfield development, during oil and gas field stimulation operations, and due to geological factors, oil and gas well casings may be damaged. Casing damage restricts the normal production of oil and gas wells and may even lead to serious consequences such as wellbore overflow. Timely and effective plugging and reinforcement of damaged casings are crucial technical measures to ensure the normal production of oil and gas wells. This paper conducts research on the 3.5in casing cable-transmitted propellant-powered patching tool. It introduces the principle and technical characteristics of the propellant-powered patching tool; optimizes the design of the expansion cone, anchoring structure, and tool parameters through finite element simulation; finally, completes the ground test of the tool and the field application of the technology and process. After patching, the full wellbore pressure test is conducted at 50MPa, with pressure stabilized for 10min and a pressure drop of 0.7MPa. Field applications show that the tool is reasonably designed, and it is the first successful application of cable transmission for such tools.