Research and Application of Gas Storage Plugging Technology for Abandoned Wells in Jidong Oilfield

In order to solve the technical problems of step-by-step layered and segmented cement squeezing and sealing of abandoned gas storage wells in Jidong Oilfield reservoir, and to ensure the integrity and sealing of the geological body construction of the gas storage, an integrated cement squeezing and sealing process and high-temperature and high-pressure cement squeezing and plugging bridge plug were studied to address the problems of frequent lifting and lowering of pipe columns during squeezing construction, loose cement squeezing and sealing, easy cement backflow and stuck drilling, and poor reservoir sealing effect in high angle wells. It has the characteristics of completing all processes such as setting, releasing, sealing test extrusion, high-pressure extrusion injection, anti backflow, and waiting for solidification under pressure in one pipe column, with safe and economical construction. The intubation adopts multiple combinations of wear-resistant seals, the rubber cylinder adopts conical extrusion, and the shoulder is protected by a vulcanized elastic skeleton, achieving high-temperature and high-pressure sealing. The bottom anti backflow mechanism is designed with dual valves, and the hydraulic system automatically closes to prevent cement backflow, ensuring reliable reservoir sealing. On site application was carried out 53 times, with a maximum inclination of 85°, a maximum formation temperature of 158 °C, a maximum extrusion pressure of 34.5 MPa, and a construction success rate of 100%. This process realizes the sealing of multiple perforation intervals, shortens the well occupation cycle, improves the sealing effect of deep deviated well reservoirs, meets the sealing process requirements of abandoned wells in Jidong Oilfield, and has broad prospects for promotion and application.