Horizontal Drilling in the U.S. Williston Basin -- Past, Present, and Future

By

Michael L. Hendricks

Hendricks and Associates, Inc, Englewood, CO

Horizontal drilling in the U. S. Williston Basin has been marked by various successes and failures over the past 10 years. The most successful horizontal programs have been in the Ordovician Red River and Mississippian Madison beds. Successful Red River B exploration and production in the Cedar Hills Field along the southern flanks of the basin has been by horizontal drilling. This is an economic project solely because of horizontal drilling.

Madison horizontal wells along the northern part of the Nesson Anticline in Rival beds have proven to be successful in tapping undrained reservoir compartments across this large anticline. These reserves would not have been economically produced without horizontal drilling.

Horizontal wells have been used to achieve increased rates of production in older Madison fields. Wiley Field along the northeast flank of the basin was initially repressurized by water injection, and reserves were captured utilizing horizontal wells.

Future use of horizontal drilling will certainly focus on preexisting fields as a means of producing reserves that would not be economically captured with conventional drilling or by depletion alone. Recognition of fields that will benefit from horizontal drilling will involve not only pressure depletion studies, but also a clear understanding of reservoir heterogeneity.

Horizontal drilling in the future will be tied closely to exploration success as new fields are managed by a combination of pressure maintenance, conventional infill drilling, and horizontal wells.

AAPG Search and Discovery Article #90004©2002 AAPG Rocky Mountain Section, Laramie, Wyoming