Short Radius Horizontal Drainhole Development and Application in the Yates Field Unit, Pecos County, Texas

by
Willard J. Tank, M.S.E.

University of Texas at Austin, 1995
Supervisor: Martin E. Chenevert

This report discusses the application of short radius horizontal drainhole technology in the Yates Field Unit, Pecos County, Texas. Horizontal drilling has been in existence since the 1940's, but became prevalent starting in the 1980's. Horizontal wells provide large increases in productivity as compared to vertical wells and remedy producing problems such as reservoir coning effects. The technology of drilling horizontal wells has evolved from long radius in new wells to short radius from existing wells. Major improvements in penetration rates and directional control have occurred.

Extensive fracture networks and a thin oil column found in Yates Field make it a good candidate for short radius horizontal technology. This has evolved from rotary systems to downhole mud motors, offering greater penetration rates and control. To date, 74 boreholes have been drilled from 65 wells resulting in substantial productivity increases. Large cost and drilling time reductions have made this an economically successful program.

Back to theses index