Mining Publication: Directionally Controlled Drilling To Horizontally Intercept Selected Strata, Upper Freeport Coalbed, Greene County, Pa.
Original creation date: January 1977
A 3-inch pilot hole was directionally drilled to intercept the Freeport coalbed horizon horizontally at Mather, Pennsylvania, as part of a Bureau of Mines degasification project. The original concept was to continue the horizontal drilling into the coalbed, after the initial intercept, with a total of three horizontal holes eventually being completed. However, the erratic thickness (0.0 to 4.3 feet) of the Freeport coalbed at Mather was not sufficient to support the horizontal drilling degasification technique, and the site was abandoned after six attempts to locate adequate continuous coal thickness. The drilling of coreholes in the immediate vicinity of proposed well paths to evaluate coal thickness is essential prior to future slant hole operations. Although mechanical failures of the new directional drilling equipment, mud pump and rig breakdowns, directional control problems, and exploratory horizontal drilling in the Freeport horizon more than doubled the anticipated cost of the pilot hole, continuing improvements in directional drilling equipment and techniques should significantly reduce the time and costs of future drilling operations.
Authors: WP Diamond, DC Oyler, HH Fields
Report of Investigations - January 1977
NIOSHTIC2 Number: 10000664
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 8231, 1977 Jan; :1-21
- Degasification System Selection for U.S. Longwall Mines Using an Expert Classification System
- Directional Drilling For Coalbed Degasification: Program Goals and Progress in 1978
- Drainage of Methane From the Overlying Pocahontas No. 4 Coalbed From Workings in the Pocahontas No. 3 Coalbed
- Drill Rig Incident
- Drilling a Horizontal Coalbed Methane Drainage System from a Directional Surface Borehole
- Methane Gas Content of the Mary Lee Group of Coalbeds, Jefferson, Tuscaloosa, and Walker Counties, Ala.
- Noise Exposure and Overhead Power Line (OPL) Safety Hazards at Surface Drilling Sites
- Rotary Drilling Holes in Coalbeds for Degasification
- Rotary Drilling Techniques Used in the Beckley Coalbed
- Use of Vertical Boreholes for Assisting Ventilation of Longwall Gob Areas
- Content source: National Institute for Occupational Safety and Health, Mining Program