Skip to content

Petition for Modification

In the matter of
Sidney Coal Company, Inc.
Rockhouse Energy Mining Company
Mine No. 1
I.D. No. 15-17651
Docket No. M-2000-107-C
30 CFR 75.1700

PROPOSED DECISION AND ORDER

On July 3, 2000, a petition was filed seeking a modification of the application of 30 CFR 75.1700 to Petitioner's Rockhouse Energy Mining Company, Mine No. 1, located in Pike County, Kentucky. The petitioner submitted supplemental information by telephone on November 7, 2000, and by mail on November 9, 2000. The Petitioner alleges that the alternative method outlined in the petition will at all times guarantee no less than the same measure of protection afforded by the standard.

MSHA personnel conducted an investigation of the petition and filed a report of their findings and recommendations with the Administrator for Coal Mine Safety and Health. After a careful review of the entire record, including the petition and MSHA's investigative report and recommendation, this Proposed Decision and Order (PDO) is issued.

Finding of Fact and Conclusion of Law

The alternative method proposed by the Petitioner (as amended by the recommendations of MSHA) will at all times guarantee no less than the same measure of protection afforded the miners under 30 CFR 75.1700 .

The active gas wells will be plugged and the petitioner will use continuous miners and longwall shears to cut through the wells, in accordance with the terms and conditions of this PDO. Any abandoned gas wells which were cleaned and plugged prior to issuance of this PDO will be individually evaluated to determine compliance with the terms and conditions described below prior to mining through, or whenever the safety barrier is reduced to a distance less than the District Manager would approve pursuant to Section 75.1700. Unless the existing records show that well to have been plugged using techniques equivalent to the amended alternative method and that information is submitted and accepted in accordance with Paragraph 2(s) as providing the required level of safety by the District Manager, the well shall be again cleaned, inadequate plugging materials drilled out and the well plugged in accordance with the terms and conditions of this proposed decision and order. The gas wells on the Mine No. 1 property intersect as many as 8 coal seams. Usually no more than 2 or 3 seams are thick enough to mine at any given location. The mine is operating on the Cedar Grove coal seam. Only the Pond Creek and Alma coal seams are lower in the stratigraphic column. The summary information provided by the petition suggests that special attention to securing and interpreting the suite of drill logs required by Paragraph 1(a)(4) is needed to assure that at a minimum the expanding cement plug extends from at least 200 feet below the lowest mineable seam through 100 feet above the highest mineable seam, unless the seams are separated by an interval greater than 300 feet, in which case each seam may be plugged individually. The "suite of drill logs", referenced above may, include but should not be limited to, drillers logs, nearby core hole records, and mine maps. Such records must be carefully evaluated for completeness and accuracy. Additional well surveys and logging may be required to locate the mineable coal seams and assure that the expanding cement is placed through the full coal seam interval. Class A cement usually requires additives in order to expand when setting. Various cement formulations have been tested and the results are available through MSHA's Technical Support Branch.

Ultimately, the complete removal of well casing and the cleaning out and plugging of the entire length of the gas well from the lowest gas producing horizon to the surface with expanding cement provides the highest degree of safety during later cut-through mining and the greatest assurance of environmental isolation of aquifers from gas and oil well pollution. Full length plugging also minimizes the need for accurate coal seam thickness and elevation measurements necessary to assure compliance with the terms and conditions of this proposed decision and order.

On the basis of the petition and the findings of MSHA's investigation, Sidney Coal Company, Inc., Rockhouse Energy Mining Company's is granted a modification of the application of 30 CFR 75.1700 to its Mine No. 1.

ORDER

Wherefore, pursuant to the authority delegated by the Secretary of Labor to the Administrator for Coal Mine Safety and Health, and pursuant to Section 101(c) of the Federal Mine Safety and Health Act of 1977, 30 U.S.C., sec. 811(c), it is ordered that Sidney Coal Company, Inc., Rockhouse Energy Mining Company's Petition for Modification of the application of 30 CFR 75.1700 in the Mine No. 1 is hereby:

GRANTED, for mining through or near (whenever the safety barrier diameter is reduced to a distance less than the District Manager would approve pursuant to Section 75.1700) plugged oil or gas wells penetrating the Cedar Grove Coal Seam and other mineable coal seams using continuous miners, conventional mining or longwall mining methods, conditioned upon compliance with the following terms and conditions:

1. Procedures to be utilized when plugging oil or gas wells.

a. Cleaning out and preparing oil and gas wells. Prior to plugging an oil or gas well, the following procedure shall be followed:

(1) A diligent effort shall be made to clean the borehole to the original total depth. If this depth cannot be reached, the borehole shall be cleaned out to a depth which would permit the placement of at least 200 feet of expanding cement below the base of the lowest mineable coalbed.

(2) When cleaning the borehole, a diligent effort shall be made to remove all the casing in the borehole. If it is not possible to remove all casing, the casing which remains shall be perforated, or ripped, at intervals spaced close enough to permit expanding cement slurry to infiltrate the annulus between the casing and the borehole wall for a distance of at least 200 feet below the base of the lowest mineable coalbed.

(3) If the cleaned-out borehole produces gas, a mechanical bridge plug shall be placed in the borehole in a competent stratum at least 200 feet below the base of the lowest mineable coalbed, but above the top of the uppermost hydrocarbon-producing stratum. If it is not possible to set a mechanical bridge plug, an appropriately sized packer or a substantial brush plug may be used in place of the mechanical bridge plug.

(4) A suite of logs shall be made consisting of a caliper survey, directional deviation survey, and log(s) suitable for determining the top and bottom of the mineable coalbeds and potential hydrocarbon producing strata and the location for the bridge plug.

(5) If the uppermost hydrocarbon-producing stratum is within 200 feet of the base of the lowest mineable coalbed, properly placed mechanical bridge plugs or a suitable brush plug described in Subparagraph (a)(3) shall be used to isolate the hydrocarbon producing stratum from the expanding cement plug. Nevertheless, a minimum of 200 feet of expanding cement shall be placed below the lowest mineable coalbed.

(6) The well bore shall be completely filled and circulated with a gel that inhibits any flow of gas, supports the walls of the borehole, and increases the density of the expanding cement. This gel shall be pumped through open-end tubing run to a point approximately 20 feet above the bottom of the cleaned out area of the borehole or bridge plug.

b. Plugging oil or gas wells to the surface. The following procedures shall be utilized when plugging gas or oil wells to the surface:

(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, the cement slurry may be pumped down the tubing so that the borehole is filled with Portland cement or a Portland cement-fly ash mixture from a point approximately 100 feet above the top of the lowest mineable coalbed to the surface with an expanding cement plug extending from at least 200 feet below the lowest mineable coalbed to the bottom of the Portland cement.) There shall be at least 200 feet of expanding cement below the base of the lowest mineable coalbed.

(2) A small quantity of steel turnings, or other small magnetic particles, shall be embedded in the top of the cement near the surface to serve as a permanent magnetic monument of the borehole. An acceptable alternative is for a monument to be erected at the surface, consisting of a section of 4-½ or larger steel casing set in cement in the borehole a minimum of 36 inches and extending at least 30 inches above ground level.

c. Plugging oil or gas wells using the vent pipe method. The following procedures shall be utilized when using the vent pipe method for plugging oil and gas wells:

(1) A 4-½ or larger vent pipe shall be run into the wellbore to a depth of 100 feet below the lowest mineable coalbed and swedged to a smaller diameter pipe, if desired, which will extend to a point approximately 20 feet above the bottom of the cleaned out area of the borehole or bridge plug.

(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 and the vent pipe shall be filled with expanding cement for a minimum of 200 feet below the base of the lowest mineable coalbed. The top of the expanding cement shall extend upward to a point approximately 100 feet above the top of the highest mineable coalbed.

(3) All fluid shall be evacuated from the vent pipe to facilitate testing for gases. During the evacuation of fluid, the expanding cement shall not be disturbed.

(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.

d. Plugging oil and gas wells for use as degasification boreholes. The following procedures shall be utilized when plugging oil or gas wells for subsequent use as degasification boreholes:

(1) A cement plug shall be set in the wellbore by pumping an expanding cement slurry down the tubing to displace the gel and provide at least 200 feet of expanding cement below the lowest mineable coalbed. The top of the expanding cement shall extend upward to a point above the top of the coalbed being mined. This distance shall be based on the average height of the roof strata breakage for the mine.

(2) To facilitate methane drainage, degasification casing of suitable diameter, slotted or perforated throughout its lower 150 to 200 feet, shall be set in the borehole to a point 10 to 30 feet above the top of the expanding cement.

(3) The annulus between the degasification casing and the borehole wall shall be cemented from a point immediately above the slots or perforations to the surface.

(4) The degasification casing shall be cleaned out for its total length.

(5) The top of the degasification casing shall be fitted with a wellhead equipped as required by the District Manager. Such equipment may include check valves, shut-in valves, sampling ports, flame arrestor equipment, and security fencing.

2. The following cut-through procedures (a-t) apply whenever the petitioner reduces the safety barrier diameter to a distance less than the District Manager would approve pursuant to Section 75.1700 or proceeds with an intent to cut through a plugged well:

Any party to this action desiring a hearing on this matter must file in accordance with 30 CFR 44.14, within 30 days. The request for hearing must be filed with the Administrator for Coal Mine Safety and Health, 4015 Wilson Boulevard, Arlington, Virginia 22203.

If a hearing is requested, the request shall contain a concise summary of position on the issues of fact or law desired to be raised by the party requesting the hearing, including specific objections to the proposed decision. A party other than Petitioner who has requested a hearing shall also comment upon all issues of fact or law presented in the petition, and any party to this action requesting a hearing may indicate a desired hearing site. If no request for a hearing is filed within 30 days after service thereof, the Decision and Order will become final and must be posted by the operator on the mine bulletin board at the mine.

_________________________________

Michael J. Lawless
Deputy Administrator
for Coal Mine Safety and Health