GROVE, KENNETH W., RANDAL M. BAYNE, and CHARLES C. HORGAN, Columbia Gas Development Corporation, Houston, TX

ABSTRACT: The Cane Creek Clastic Interval of the Pennsylvanian Paradox Formation-An Exciting New Horizontal Target Part II: Horizontal Drilling Technology: A Case Study

In 1991, Columbia Gas and its partners completed the first medium-radius horizontal well in Utah as a Cane Creek producer. The Kane Springs Federal #27-1 had an initial production of 914 BOPD. Since that time, two additional high-volume producers have been completed and a fourth well has been temporarily abandoned. Columbia's horizontal success rate to date is 75%, a marked improvement over vertical exploitation.

An integrated program incorporating subsurface geology, seismic interpretation, and well design has been critical to Columbia's success. Oil-base mud systems are used to maintain hole integrity in the thick Paradox salt sequence and to permit optimal drilling mechanics during the angle-building phase. A protective casing string is set in the top of the Cane Creek prior to the final landing and drilling of the horizontal leg. Measurement-while-drilling logging systems are essential during the angle-building phase and for successfully staying in-zone in the lateral phase. Oriented horizontal cores provide bedding attitudes and fracture directions. Unpredictable, abrupt changes in surrounding salts and structuring within the Cane Creek interval require constant monitoring by the well-sit team to successfully land and stay in the target zone. Real-time well-site decision-making authority is an absolute must during steering operations.

Pore-fluid pressure gradients exceed 0.85 psi/ft, but only in the presence of open fractures. Second-order folds with amplitudes of 15-100 ft and apparent wavelengths of 300-3000 ft have been encountered. Core data suggests the presence of a regional northeast-southwest, near vertical, open-fracture system. Additional drilling should continue to produce clearer insights in this newly developing horizontal play.

AAPG Search and Discovery Article #90993©1993 AAPG Rocky Mountain Section Meeting, Salt Lake City, Utah, September 12-15, 1993.