For over a decade, EPA Region IV allowed the use of annulus gel (bentonite) in Class II injection wells. But in April, 1997, Region IV abruptly reversed its policy on annulus gel.| Home | Tech & Tips | UIC |
"Adding materials to the liquid in the annulus to change the properties of the liquid to prevent or diminish flow through the leak or to mechanically plug the leak" has been an accepted practice in the UIC program (National UIC Technical Workgroup Final Work Product #5, December 15, 1998). The point of such an exercise is to get an injection well to pass its mechanical integrity test (MIT) without more extensive remediation that may or may not be effective, such as squeeze cementing (a remedial procedure that often causes more problems than it solves). Expensive commercial products include ANJEL® and ANGARD®, marketed by Halliburton Energy Services (these are silicate gel preparations; interestingly, operators have long added small quantities of sodium silicate a/k/a "liquid glass" to the annulus of injection wells that have failed an MIT).
The use of bentonite gel as an annulus fluid in Region IV was pioneered by David W. Clapp, P.E., a Halliburton engineer at the time. It has been used in scores of wells in Region IV. When I was first informed of the use of annulus gel, I was amazed at the generosity of Region IV in accepting such a procedure, and acted the devil's advocate in my early discussions about said technology with Fred McManus, then a UIC enforcement officer (see May 17,1990 letter). Annulus gel was researched at EPA's Kerr Lab in Ada, Oklahoma, and it is likely that the use of annulus gel as an acceptable annular fluid in Region IV for the standard annular pressure test (SAPT) grew out of said research. (Sadly, the records at Kerr Lab cannot help since they have apparently been destroyed by EPA, an unforgivable loss of basic research data on a wide range of UIC issues.)
It is simply nuts that a long accepted practice at Region IV would be tossed out at the caprice of a single enforcement officer. Accordingly, the peculiar reversal of policy on annulus gel at Region IV was challenged in a pair of UIC permit appeals before the Environmental Appeals Board (EAB) in UIC Appeal Nos. 98-3 & 98-5, and later before the U.S. Court of Appeals for the Sixth Circuit (unfortunately, the court dismissed the pro se UIC permit appeal for lack of standing of the petitioner). Interestingly, Region IV enunciated for the first time in its EAB pleadings what appears to have been its principle, and somewhat disingenuous, objection to annulus gel, that it will not inhibit corrosion in the annular area. The appellants, in response, pointed out that a fresh water gel would be less corrosive than plain brine where no other additives were used with either. The EAB remanded the annulus gel issue (and six others), and after over 1-1/2 years, Region IV finally addressed the remanded issues in a December 1, 2000 letter.
In addressing the remand, Region IV now alleges it "...can find no instances where gel was approved for use as an annular fluid additive in Region IV." Region IV cites a deposition of Syd H. Levine, your humble author, where I refused to name names of operators I knew had used annular gel. They neglected to mention that I testified that annulus gel had definitely been used in at least three different counties in Kentucky, and that said testimony is uncontradicted. They go on to say, "The Region can find no evidence to support the contention that the Region's decision not to allow the use of gel is a reversal of Region IV's past practices." But it is a reversal of past practices, and putting Region IV EPA's record keeping in perspective, they have an all too frequent history of being unable to locate documents pursuant to discovery and FOIA requests (they have been unable to produce even one page about the basis for their SAPT procedures, the most common MIT used in Region IV).
Region IV reiterates the nonsensical position that gel will not inhibit corrosion in the annular area, but gel prepared with fresh water would be less corrosive than the brine contemplated in the UIC permits at issue (of course corrosion inhibitors can be added to any annulus fluid, but plain brine is certainly a worse choice than a fresh water gel). Region IV then expresses the opinion that "...the gel could contribute to or mask the loss of a well's mechanical integrity." How could gel possibly contribute to a loss of mechanical integrity? It cannot, but what it can do is fill tiny leaks with "filter cake", thus repairing very small leaks that do not constitute "significant leaks". All leaks are not prohibited by the UIC regulations, only significant leaks (the history of the UIC regulations make it clear that a significant leak is something more than no leak at all); this is a critical concept since all MITs have some threshold past which smaller leaks cannot be detected. The SAPT has a resolution on the order of one (1) gallon per day, certainly not a significant leak in the typical Class IIR injection well (in some UIC programs, leaks one or two orders of magnitude larger are not considered significant). Plain "neat" gel with no lost circulation additives could never seal a significant leak, all it can do is allow an injection well to pass an overly sensitive MIT like the SAPT, where said well was never a threat to the environment.
Region IV states, "In particular, the gel could conceivably fill a leak in injection tubing or the long string casing, enabling the well to demonstrate mechanical integrity, and later become displaced, resulting in a loss of mechanical integrity." Neat bentonite gel could never produce an effective filter cake plug in a big enough casing breach to fulfill the above scenario. It can only plug very small defects, and because the entire annular space would be filled with gel, said repair is quite permanent. Region IV expresses concern that 40 CFR §144.51(q) or 40 CFR §144.12 might be violated, but that is not possible with neat gel, since said gel cannot produce an effective seal for a leak that could rise to any reasonable definition of "significant leak" as contemplated at 40 CFR §146.8. All the foregoing technical basics were well understood by Region IV personnel when annulus gel was discussed some ten years ago (after all, it was an EPA Region IV employee who suggested the use of annulus gel to operators in Hancock and Ohio Counties, Kentucky, in the first place.).
Region IV has cited the language in the National UIC Technical Workgroup Final Work Product #5 as justification for the continued refusal of Region IV to allow the resumption of the use of annulus gel; said document is also mentioned in the December 1, 2000 letter discussed in the foregoing three paragraphs. The document requires, "Any additive used to restore MI must be marketed by its manufacturer for the purpose of stopping leaks for the long term. The manufacturer must stand behind the product and be willing to work with injection well operators and the USEPA to develop a testing and use history which will provide assurance that the product is effective." But bentonite annulus gel is a "poor boy" technology with no manufacturer having sufficient economic incentive to play the part EPA envisions. However, bentonite annulus gel has worked beautifully in many wells in Region IV (and perhaps elsewhere) and should be allowed as it was in the past.
The latest twist on this old story is that 300psi is offering annulus additive products, one of which is nothing more than bentonite annulus gel with other additives. 300psi markets its products all over the country in both primacy and direct implementation areas, including Kentucky. 300psi reportedly received the blessings of Region IV from Ken Harris, a Region IV UIC enforcement officer, but like the earlier approval granted by Fred McManus, Region IV now denies same. Interestingly, none of the 300psi products, nor any of the Halliburton products have ever been approved under National UIC Technical Workgroup Final Work Product #5. There is just no nice way to say it, but EPA Region IV outright lied to the EAB and to the Sixth Circuit Court of Appeals about the use of bentonite annulus gel in Kentucky. Will EPA now take action against 300psi or Halliburton? Stay tuned for the next Kafkaesque development.
Annulus gel is a cost effective solution, available to the smallest "mom and pop" operators. Region IV has acted in a capricious manner and should allow the continued use of annulus gel.
See also Annulus Gel - EAB Second Petition Excerpt and Pro Se UIC Permit Appeal.