Williston Basin Study

The Integrated Reservoir Solutions Division of Core Laboratories is offering to interested companies the results of a geological and engineering evaluation of the Upper Devonian Duperow and Birdbear (Nisku) formations of eastern Montana and western North Dakota.

Project Objectives

• Define and document the depositional facies of the stratigraphic sequence spanned by the two formations
• Describe the diagenetic features and sequences characteristic of the two formations, particularly with respect to porosity evolution and destruction
• Illustrate structural, stratigraphic and petrophysical characteristics pertinent to exploration for these carbonate reservoirs

This report contains a database generated from more than 2500 wells, including description of cored intervals from 105 wells and outcrop sections. Wireline logs were acquired and used for control points in the basin with supplemental logs and production data being obtained from public domain sources.

Three case histories comprise the engineering portion of this project. Each well represents major producing reservoir lithotypes of the Williston basin. The engineering parameters evaluated include:

• Porosity and permeability relationships within the producing zones
• Overburden pressure effects on porosity and permeability
• Evaluation of electrical parameters for log interpretation
• Evaluation of capillary pressure relationships of each producing region
• Evaluation of gas-oil and water-oil relative permeability relationships
• Determination of pore size distributions
• Evaluation of acoustic transit times to aid in log calibration in the subject zones