2020 Well Abandonment Policy Issues and Knowledge Gaps

Public Policy Issue Associated Knowledge Gap(s)

Characterize the Source of SCVF/GM to Identify Leakage Pathways, Establish an Appropriate Threshold Concentration for Well Repair, and Identify Long-term Monitoring Solutions.

  • Improve source identification methodology, as characterizing the source of SCVF/GM remains challenging.
  • Establish better gas sampling methods and standards, as samples become unstable over time.  Gas source characterization is interpretational and unreliable.
  • Analyze impacts from both SCVF/GM and repair operations to determine an appropriate SCVF/GM threshold.
  • Identify a cost-effective long-term monitoring solution.

Research Well Integrity to Establish a Permanent Barrier Criteria.

  • Investigate bridge plugs and alternatives. Assess cost, longevity, and failure probability.
  • Gain a better understanding of the seal integrity between the well casing and cement.

Determine a Criteria for Cement and Cement Alternatives for SCVF/GM Repair.

  • Create a tool that can assess the bond quality behind pipe, for both cement and cement alternatives.
  • Reduce wellbore leakage during drilling though increased knowledge and improving cementing practices.

D20 requires fresh water for abandonments, and uninhibited fresh above BGWP. This does not sit well with many operators, because of the belief that fresh water will accelerate corrosion (especially at the air-water interface at surface, which will be necessary for freeze protection).

Other regulatory environments require a range of fluids, from “nonporous material” (Pennsylvania – widely interpreted to be any liquid you want as long as it’s not air) to “salt gel fluid” (Texas), “fluid dense enough to overpressure open formation below” (US offshore)

  • What are the long term impacts of these fluids on well elements? What are the corrosion rates in various well conditions (mobile formation gas, etc) with each fluid? What is the impact to groundwater, if the well elements eventually fail and the fluid inside casing eventually contacts GW?