Technical Discussion of Packer Setting Depth Issues
Statewide Rules 9 and 46 both require that injected fluids remain confined to the authorized injection/disposal interval. The technical review of the packer setting depth evaluates whether confinement of injected fluids can be ensured.
Statewide Rule 9, which governs disposal into non-productive formations, requires that the packer be set within 100 feet of the permitted zone.
Statewide Rule 46, which governs injection or disposal into productive formations, provides greater flexibility within the general requirement that injected fluids be confined within the authorized injection interval. Rule 46 states that the packer must be set at least 200 feet below the production casing cement and at least 150 feet below the deepest usable quality groundwater. If, for example, a well was completed with 1200 feet of annular cement above the injection interval and the interval had 1000 feet of overlying clay/shale, then the packer could be set 1000 feet above the permitted zone. If, on the other hand, there was a small water sand 110 feet above the permitted zone, then the packer must be set below that water sand. One option to deal with this is to amend the proposed permitted injection zone to include that little water sand.
The suitability of the proposed packer setting depth is checked during the technical review of the permit application. If there are any potential injection or disposal zones between the proposed packer depth and the top of the permitted injection zone, then the packer setting depth will be rejected. The applicant will have a choice of either setting the packer closer to the injection zone, or raising the permitted injection zone to include the potential injection or disposal zone within the permitted injection zone.
Moving the packer uphole after the permit is issued will likely result in the Mechanical Integrity Test (MIT) being ruled inconclusive.