Open AccessIncreased oil production and reserves from improved completion techniques in the Bluebell field, Uinta Basin, Utah. Annual report, October 1, 1995--September 30, 1996
Author(s) -
Craig D. Morgan,
M. Lee Allison
Publication year - 1997
Language(s) - English
Resource type - Reports
DOI - 10.2172/513530
Subject(s) - geology , completion (oil and gas wells) , reservoir modeling , drilling , structural basin , outcrop , fluvial , reservoir engineering , clastic rock , oil field , hydrology (agriculture) , green river formation , carbonate , petroleum engineering , mining engineering , geomorphology , paleontology , petroleum , geotechnical engineering , engineering , metallurgy , mechanical engineering , materials science
The Bluebell field is productive from the Tertiary lower Green River and Wasatch Formations of the Uinta Basin, Utah. The productive interval consists of thousands of feet of interbedded fractured clastic and carbonate beds deposited in a fluvial-dominated lacustrine environment. Wells in the Bluebell field are typically completed by perforating 40 or more beds over 1,000 to 3,000 vertical feet (300-900 m), then stimulating the entire interval. This completion technique is believed to leave many potentially productive beds damaged and/or untreated, while allowing water-bearing and low-pressure (thief) zones to communicate with the wellbore. Geologic and engineering characterization has been used to define improved completion techniques. A two-year characterization study involved detailed examination of outcrop, core, well logs, surface and subsurface fractures, produced oil-field waters, engineering parameters of the two demonstration wells, and analysis of past completion techniques and effectiveness. The characterization study resulted in recommendations for improved completion techniques and a field-demonstration program to test those techniques. The results of the characterization study and the proposed demonstration program are discussed in the second annual technical progress report. The operator of the wells was unable to begin the field demonstration this project year (October 1, 1995 to September 20, 1996). Correlation and thickness mapping of individual beds in the Wasatch Formation was completed and resulted in a. series of maps of each of the individual beds. These data were used in constructing the reservoir models. Non-fractured and fractured geostatistical models and reservoir simulations were generated for a 20-square-mile (51.8-km{sup 2}) portion of the Bluebell field. The modeling provides insights into the effects of fracture porosity and permeability in the Green River and Wasatch reservoirs