Implementation of temporary packer isolation of productive zones for long-term gas well workover operations and viscoelastic system for safe packer removal

Introduction. Long-term repair work with killing gas wells with saline solutions can significantly worsen the reservoir properties of productive formations due to water penetration into the reservoir rock. The Neocomian formations have a high potential for gas production and are developed using horizontal wells, the length of which is more than 1000 m. In this regard, when carrying out workovers of gas wells, an urgent task is to use methods of temporary isolation of the formations to maintain high production rates. Despite extensive experience in the use of retrievable packers for gas-blocking operations, the technologies for safely retrieving this type of equipment without the involvement of specialized equipment have not been developed.

Target. The use of a bridge packer plug for temporary isolation of the productive horizon and a viscoelastic composition for its safe extraction during long-term repair work on gas wells.

Materials and methods. To reduce the negative impact of killing fluids on the porosity and porosity characteristics of the formation during repair work, a technology for installing a bridge packer plug for temporary isolation of the formation is proposed. Due to the inaccessibility of the fields of the Far North, it is proposed to carry out work on extracting the packer plug without the involvement of specialized equipment by pumping a viscoelastic composition into the liner interval below the packer plug after its failure to isolate the formation for the duration of tripping operations.

Results. A solution was tested for temporary isolation of productive formations by using a retrievable packer device. The extraction of the packer device was carried out in a safe mode by using a viscoelastic composition with adjustable characteristics. After the repair work on the well, the design production indicators were achieved, and the reservoir properties of the reservoir were fully preserved.

Conclusion. The use of the technology of installing a recoverable packer with its subsequent extraction without the involvement of specialized equipment is a highly promising solution for maintaining the productivity of the Neocomian formations.

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