Method of casing integrity assessment in an interval where a cement plug is to be installed in a well proposed for abandonment
This invention relates to the method of assessing the integrity of primary and secondary barriers in the interval where a cement plug is to be installed in the well proposed for abandonment. The technical result of the invention is to enhance the accuracy of wellbore barrier integrity assessment. The method of well integrity assessment below production packer, including inner and outer casings, tubing string and production packer installed inside the casing, and cement sheath and adjacent rocks, comprising the following phases: Identification of the target zone for cement plug installation; installation of a temporary cement plug below the target zone; pressure testing and assessment of tubing and below-packer zone integrity based on steady pressure data or pressure variation in time; creation of a perforation zone in casing and cement below production packer in the target zone; conducting a logging survey including noise, temperature, defectoscopy, and production logging in the target zone during a repeat pressure test; issuance of a findings report on casing and cement integrity and subsequent installation of a cement plug for well abandonment, including rigless operations or remedial cementing at designated locations where integrity failures have been identified on the basis of logging data.
1. A method of well integrity assessment in an interval including a casing, a tubing string and a production packer placed inside the casing, and a cement sheath and rocks adjacent thereto, the method comprising:
identifying a target zone below the production packer for installing a cement plug;
installing a temporary cement plug below the target zone;
pressure testing the target zone;
assessing an integrity of the target zone based on steady pressure data or pressure variation in time;
perforating a zone in the casing and the cement sheath in the target zone below the production packer;
initiating a repeat pressure test of the target zone;
during the repeat pressure test, conducting a logging survey including acoustic, temperature, defectoscopy, and production logging in the target zone;
issuing a findings report on integrity of the casing and the cement sheath for subsequent installation of the cement plug for well abandonment via rigless operations or remedial cementing at designated locations where integrity failures have been identified based on the logging survey.
2. The method according to claim 1 , further comprising determining a flow path in the well behind the casing and in the cement sheath in the designated locations where integrity failures have been identified based on the logging survey.
3. The method according to claim 1 , further comprising determining wellbore flow, cement channeling due to completion integrity breaches, fracture flow and porous reservoir flow in the designated locations where integrity failures have been identified based on the logging survey.
4. The method according to claim 1 , further comprising determining behind-casing fluid loss or fluid inflow zones in the designated locations where integrity failures have been identified based on the logging survey.
5. The method according to claim 1 , further comprising perforating the casing and placing the production packer in the casing at another location in the well.
6. A method of well integrity assessment in an interval including a casing, a tubing string and a production packer placed inside the casing, and a cement sheath and rocks adjacent thereto, the method comprising:
identifying a target zone above the production packer for cement plug installation;
installing a temporary cement plug below the target zone;
pressure testing the target zone;
assessing an integrity of the target zone based on steady pressure data or pressure variation in time;
perforating the casing and cement sheath in the target zone above the production packer;
initiating a repeat pressure test of the target zone;
during the repeat pressure test, conducting a logging survey including acoustic, temperature, defectoscopy, and production logging in the target zone;
issuing a findings report on integrity of the casing and the cement sheath for subsequent installation of the cement plug for well abandonment via rigless operations or remedial cementing at designated locations where integrity failures have been identified based on the logging survey.
7. A method of well integrity assessment in an interval including a casing, a tubing string and a production packer placed inside the casing, and a cement sheath and rocks adjacent thereto, the method comprising:
identifying at least two target zones below the production packer for cement plug installation;
pressure testing the at least two target zones;
assessing an integrity of the at least two target zones based on steady pressure data or pressure variation;
perforating the casing and cement sheath in the at least two target zones;
installing an inflatable packer between the at least two target zones;
initiating a repeat pressure test of the at least two target zones;
during the repeat pressure test, conducting a logging survey including acoustic, temperature, defectoscopy, and production logging in the at least two target zones;
issuing a findings report on integrity of the casing and the cement sheath for subsequent installation of the cement plug for well abandonment via rigless operations or remedial cementing at designated locations where integrity failures have been identified based on the logging survey.
8. A method of well integrity assessment in an interval including a casing, a tubing string and a production packer placed inside the casing, and a cement sheath and rocks adjacent thereto, comprising the following phases:
identifying at least two target zones for cement plug installation, wherein one target zone is situated above the production packer and the other is situated below the production packer;
pressure testing the at least two target zones;
assessing an integrity of the at least two target zones based on steady pressure data or pressure variation in time;
perforating the tubing string, the casing, and the cement sheath in the at least in two target zones;
installing an inflatable packer between the at least two target zones;
initiating a repeat pressure test of the target zone;
during the repeat pressure test, conducting a logging survey including acoustic, temperature, and defectoscopy in the at least two target zones;
issuing a findings report on integrity of the casing and the cement sheath for subsequent installation of the cement plug for well abandonment via rigless operations or remedial cementing at designated locations where integrity failures have been identified based on the logging survey.
9. A method of well integrity assessment in an interval including a casing, a cement sheath and rocks adjacent thereto, the method comprising:
identifying a target zone for cement plug installation;
installing a temporary cement plug below the target zone;
pressure testing the target zone;
assessing an integrity of the target zone based on steady or dropping pressure data;
perforating the casing and the cement sheath in the target zone above the temporary cement plug;
initiating a repeat pressure test of the target zone;
during the repeat pressure test, conducting a logging survey including acoustic, temperature, defectoscopy, and production logging in the target zone;
issuing a findings report on integrity of the casing and the cement sheath for subsequent installation of the cement plug for well abandonment via rigless operations or remedial cementing at designated locations where integrity failures have been identified based on the logging survey.