Comparison of rotary and in-hole motor techniques for drilling horizontal boreholes in coal.
Kravits-SJ; Sainato-A; Finfinger-GL
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 8933, 1985 Jan; :1-31
This Bureau of Mines report describes and compares the procedures, capital investments, and operating costs of rotary and in-hole motor drilling techniques used to drain methane gas from the Pittsburgh coalbed in an underground mine located in southwestern Pennsylvania. A timestudy was conducted during the drilling of each of two boreholes, and the data were collected to serve as a base for comparing drilling procedures and operating costs. Findings indicate that drilling with an in-hole motor offers four advantages over rotary drilling; namely, an increase in drilling productivity, fewer worker-hours required, ease of maintaining vertical and horizontal bit trajectory, and less expensive drilling cost per foot of borehole.
Mining-industry; Coal-mining; Underground-mining; Methanes; Methane-drainage; Methane-control; Explosive-gases; Explosive-atmospheres
IH; Report of Investigations
NTIS Accession No.
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 8933