Supervision of Injection Well Testing and Abandonment
- Underground salt and potash solution mine covering 4,500 acres
- Multiple injection and recovery wells with depths of 2,000 to 4,000 feet.
- Evaluated mine leakage tests
- Supervised mechanical integrity tests
- Supervised well plugging and abandonment
- Prepared reports in compliance with the underground injection control permit
An EarthFax client operates an underground salt and potash mine on approximately 4,500 acres in southeastern Utah. This mine was originally constructed as a conventional room-and-pillar operation, but was eventually converted to a solution mine due to deformation of the ore body by the excessive overburden pressures (with typical overburden depths of 2,000 to 4,000 feet). Operating as a solution mine, the client circulated water through the mine and pumped the mineral-laden water into surface evaporation ponds.
With time, the brine corroded many of the deep injection and recovery wells, creating the potential for leakage of brine into shallower aquifers and impacting groundwater that had other beneficial uses. EarthFax was retained to help this client avoid these impacts by complying with and revising, as necessary, their underground injection control permit. The services that we provided include the following:
- Evaluated data collected from prior tests conducted by the mine to determine if leakage was occurring between the mine and overlying aquifers. This included a review of the weekly ratio of the volume of water injected versus the volume of water extracted from the mine, an assessment of mine shut-in tests, and an evaluation of pressure tests performed on individual wells. Based on this evaluation, it was deemed necessary to plug certain wells and operate the mine under a “pumped” condition rather than a “pressurized” condition.
- Evaluated alternative mechanical integrity tests to determine the ability of the injection and recovery wells to be operated in accordance with the underground injection control permit. Site-specific conditions required that standard protocols be modified in some cases. We prepared documentation to obtain regulatory approval for mechanical integrity testing, supervised the testing of 11 injection and recovery wells, and prepared reports of the test results for submission to the regulatory authority.
- Supervised plugging and abandonment of 13 injection and recovery wells. Prior to plugging, the wells were assessed by wireline logging (cement evaluation tool, cement bond log, gamma log, casing collar locator, sonic logs, temperature logs, and caliper logs). We reviewed these logs with the plugging contractor and made field decisions regarding appropriate equipment and techniques to ensure proper plugging and abandonment. One unique aspect of this project involved the design of floating cement in some cases to serve as plugs in sections of the wells where the casing had corroded. We assessed all abandonment data and prepared reports to ensure that the intent of the permit was met.