Current through Register Vol. XLI, No. 37, September 13, 2024
Section 38-23-8 - Plugging of Coalbed Methane Wells When a Workable Coal Seam is Encountered8.1. All coalbed methane and gob wells shall be plugged upon abandonment and shall be plugged in accordance with a plan filed and approved by the Chief. The approved method of plugging shall require the plugging of the well will be sufficient to allow the well to be mined through safely.8.2. Method of Plugging. 8.2.1. Materials Used in Plugging. Any non-porous materials including gels and cements to be used in plugging must be specified in the work order portion of Form WW-6B. All cement, except where expanding cement is used in conjunction with plugging shall be American Petroleum Institute Class A Ordinary Portland Cement with no greater than 3% calcium chloride or alternates approved by the chief. AH non-porous materials used in conjunction with plugging shall be at least six percent (6%) bentonite gel. If the operator furnishes satisfactory proof that different cement or non-porous material types are adequate, the Chief may approve use of such different cement or non-porous materials. Materials and cements must be of a kind and quality accepted by the oil and gas industry and approved by the Chief as suitable for the intended purpose and which otherwise comply with all provisions of law and accepted standards. The Chief may approve the use of non-standard material or cement.
8.3. Length of Plug - All cement plugs, other than those across coal seams, shall be at least one hundred (100) feet in length unless a variance from such a requirement is granted pursuant to Section 16.8.4. Retrieving Casing and Completing a Seal - The operator shall make reasonable efforts to cut and pull all recoverable casing (as determined by methods approved by the Chief or his authorized representative). Equipment used to pull recoverable casing shall be rated and rigged at or above one hundred and fifty percent (150%) of the estimated weight of the heaviest string of recoverable casing, unless otherwise approved by the chief or his authorized representative. Sufficient instrumentation shall be used to accurately indicate the pulling force applied. When the fresh water casing has not been cemented to surface and the casing cannot be pulled, the operator shall make reasonable attempts to perforate the casing and squeeze cement behind the casing in the vicinity of the fresh water zones to prevent the contamination of the fresh water zone.8.5. Cleaning Out and Preparing Wells. 8.5.1. The well shall be cleaned out along its entire length or, in the case of gob wells, if it is not feasible to clean out along the entire length, the well shall be cleaned to the lowest practical depth or at least below the lowest workable coal seam.8.5.2. Either at the time of drilling the well or at least prior to the application to plug, a suite of logs shall be made consisting of a caliper survey if an open hole section is to be plugged, directional deviation surveys (at a minimum), logs or drillers' records suitable for determining the top and bottom of all coalbeds, logs or other mechanical means to determine the lengths along the casing where cement is present, and the location of the bridge plugs. If the required logs are done at the time of drilling then they shall be filed with the Chief and be available to the coal owner and operator.5.5.3. When cleaning a well, and based on the information determined in Section S.5.2, a diligent effort will be made to remove all uncemented casing from at least 20 feet below to 100 feet above each workable coal seam in the well bore. Any remaining uncemented casing, as determined by cement bond log, shall be perforated or ripped at a minimum of 200 feet below and 100 feet above each workable coalbed at intervals spaced close enough to permit expanding cement slurry to infiltrate the annulus between the casing and the well bore.8.5.4. The wellbore shall be completely filled and circulated with a gel that inhibits any flow of gas, supports the walls of the borehole, and densities the expanding cement. This gel shall be pumped through open-end tubing run into the well.8.6. Plugging Coalbed Methane Wells to the Surface. The following procedures shall be used when plugging coalbed methane wells to the surface:8.6.1. A cement plug shall be set in the wellbore by pumping an expanding cement slurry down the tubing to displace the gel and fill the borehole to the surface. As an alternative, after the expanding cement slurry is pumped down the tubing so that the wellbore is filled to a point approximately 100 feet above the top of the topmost workable coalbed, materials permitted under Section 8.2 may be used to fill the wellbore from that point to the surface.8.6.2. A small quantity of steel turnings, or other detectable material, shall be embedded in the top of the cement near the surface to serve as a permanent magnetic monument of the borehole.8.7. Plugging Coalbed Methane Wells Using the Vent Pipe Method. The following procedures shall be used when using the vent pipe method for plugging coalbed methane wells: 8.7.1. A vent pipe sized appropriately based on the existing casing in the well shall be run into the wellbore to a depth of the lesser of the bottom of the well or 100 feet below the workable coalbed and cemented to 100 feet above the uppermost workable coalbed.8.7.2. A cement plug shall be set in the wellbore by pumping an expanding cement slurry, Portland cement, or a Portland cement-fly ash mixture down the tubing to displace the gel so that the borehole is filled with cement. The borehole shall be filled with expanding cement from the bottom of the well to 100 feet above the target seam or producing horizon.8.7.3. All fluid shall be evacuated from the vent pipe to facilitate testing for gases.8.7.4. The top of the vent pipe shall be protected to prevent liquids or solids from entering the wellbore, but permit ready access to the full internal diameter of the vent pipe when necessary.8.7.5. The vent shall extend at least 30 inches above the ground and have a tag affixed with the well identification or in some manner identify the well.8.8. The Chief may allow alternate plugging methods or waive certain of the requirements of Sections 8.5 and 8.6 provided the coal owner and operator consents in writing to such alternate methods. The chief may also require additional steps to be taken during plugging to insure conformance with any requirements a state or federal agency which has jurisdiction over mine safety may impose or require for a safe mine through of the well.8.9. An affidavit of plugging shall be filed with the Chief, stating the plugging method used and any deviations from the proposed plugging plan. 8.10. Plugging when a coalbed methane well does not encounter a workable coalbed, including the target horizon, or a gob well does not encounter a workable coal seam. 8.10.1. When a coalbed methane well or gob well does not encounter a workable coalbed, upon abandonment shall be plugged in accordance with the provision of this Section.8.10.2. All materials used in plugging shall be in accordance with Section 8.2.8.10.3. The wellbore shall be filled from the bottom of the well with non-porous material and cement to the surface. At a minimum, a cement plug extending from the surface to a depth of 100 feet shall be placed in the well.8.10.4. An affidavit of plugging shall be filed with the Chief by the operator stating the method of plugging used and any deviation from the plugging plan.8.11. Permanent Marker. - Except as provided below, upon the completion of the plugging and filling of any abandoned CBM well which was not subsequently converted to a vent hole by the coal operator, a permanent monument or marker consisting of a length of pipe (minimum diameter size six (6) inches) filled with concrete (or the equivalent thereof approved by the Chief) shall be erected over the well. The marker shall extend no less than thirty (30) inches above the surface and no less than ten (10) feet below the surface and into the well, and shall be sealed with concrete for the purpose of making the marker permanent. The API well identification number which consists of the state (047), county (001 through 109), and permit number shall be attached or stamped in a permanent manner to said monument. Such number shall be no less than one half (1/2) inch in height and detectable by any interested person approaching the monument. The erection of a monument shall in no way interfere with the bleeder pipe from the well where such pipe is required, or the vent or other device installed pursuant to W.Va. Code § 22-6-24. Such monument shall be accurately described on Form WR-38, "Affidavit of Plugging and Filling Well" as well as the time and manner of plugging and filling and shall be approved by the Chief as a satisfactory landmark which may be used as such in the location of adjacent wells. Two (2) permanent reference points with courses and distances from the abandoned well shall be designated and prescribed on the plat required by 38 CSR 18-13.1 in the form prescribed by 38 CSR 18-9, accompanying the Form WW-6A, "Notice of Intention to Plug and Abandon a Well", or if any change in the plat is necessary, accompanying Form WR-38, "Affidavit of Plugging and Filling Well".