Microhole Coiled Tubing Drilling: A Low Cost Reservoir Access Technology

Although the microhole coiled tubing drilling rigs have been used extensively in Canada, their application in the U.S. has been very limited. In an effort to introduce this technology to the U.S. operators, GTI, with the support of DOE∕NETL, has completed a successful field testing of the coiled tubing microhole drilling technology. In this paper we report results of field testing of the system in 25 wells drilled in the Niobrara unconventional gas play of Kansas and Colorado. The objective of the field test was to measure and document the rig performance under actual drilling conditions. In these tests, a coiled tubing drilling rig (designed and built by T Gipson with Advanced Drilling Technologies Inc.) was utilized. The rig operations have continued to improve to the point where it now drills a $3100ft$ well in a single day. Well cost savings of approximately 30% over conventional rotary well drilling have been documented. A description of the rig and a summary of its performance in the Niobrara unconventional gas play are included. In addition, an estimate of economic advantages of widespread application of microhole drilling technology in the lower 48 states is presented.