September 2004
Features
Petroleum Technology Digest: Air hammers cut Barnett Shale drilling time in half
To reduce drilling time and costs on Barnett Shale wells, Hallwood Energy used air hammers with diamond insert bits. For vertical wells, time from spud to total depth dropped from 12 – 14 days to 6 – 8 days, representing about $72,000 per well savings. In horizontal wells, time from spud to kick-off point has dropped from 10 – 12 days to 5 – 6 days. Costs associated with the air-hammer/ diamond-insert bit drilling approach (air compressor, fuel, hammer, hammer bit, supervision) are offset by saving on mud and fewer roller cone bits, stabilization, and/or mud-motor costs. In 6 of 12 wells drilled through June 2004, half were drilled with a single bit/trip. The drilling team expects that its goal of drilling 80%, or 8 of 10 wells, with a single trip, can be reached during 2004.
