DE-AC21-93MC30086

Goal:
To increase recovery of natural gas from naturally fractured tight reservoirs.

Background:
This effort integrates seismic, aeromagnetc and other geophysical data to develop a methodology for predicting and detecting natural fractures in tight gas reservoirs. The tool will be able to assess the orientation, intensity and permeability of natural fractures, which are the key flow paths in tight sand formations. The primary focus of this project is on known natural gas producing areas of the Piceance Basin and other basin areas of the Rocky Mountain region.

Performer: Advanced Resources International

Location:
Arlington, Virginia 22201

Project Impact:
This project has successfully demonstrated the value of conducting an in-depth natural fracture study of low-permeability gas reservoirs in the Rocky Mountain region of the United States. The project CD-ROM is still a much sought-after product based on the continuing requests received at NETL and the interest shown at professional meeting exhibits.

Accomplishments:
This study and others have shown that the resource and reserve potential in the Rocky Mountain States is very large. Economically viable production of natural gas from tight reservoirs can be achieved in formations that have been adequately fractured by geologic processes. These fractures then provide the flow channels necessary to extract the trapped gas. Specific accomplishments from this project are described below.

• Demonstrated in the southern Piceance Basin of western Colorado that natural fracture clusters are genetically related to stress concentrations (also called stress perturbations) associated with local deformation such as faulting. Locating natural fracture clusters are believed to be a key to improving the success rates for producers in these areas.
• Demonstrated techniques for sweet-spot delineation in a relatively new and under explored; tight gas from continuous-type Upper Cretaceous reservoirs of the Greater Green River Basin (GGBR). This effort included data acquisition/processing, base map generation, geophysical and remote sensing analysis and the integration of these data and analysis.
• In support of Union Pacific Resources and DOE-planned horizontal drilling efforts, this project acquired seismic and depth-conversion data. Mapping of the major fault geometry and analysis of displacement vectors was conducted and a natural fracture prediction model was developed.
• Building on fundamental fracture characterization work and structural analysis using satellite and potential field data, the GGRB was divided into partitions that will be used to analyze the resource potential of the Frontier and Mesaverde upper Cretaceous tight gas play. A total of 20 partitions were developed, which will be instrumental for examining the Upper Cretaceous play potential.

Current Status and Remaining Tasks: This project was completed in 1999. A CD-ROM entitled "Detection and Analysis of Naturally Fractured Reservoirs" released at the 1998 AAPG Annual Convention in Salt Lake City, Utah is available upon request from NETL.

Project Start Date: September 30, 1993
Project End Date: July 31, 1999

DOE Contribution: $3,705,637
Performer Contribution: $510,427

Contact Information:
ARI - Vello Kuuskraa (703-528-8420 or advancedres@intr.net)
NETL - William Gwilliam (304-285-4401 or william.gwilliam@netl.doe.gov)

Additional Information:
A CD-ROM entitled "Detection and Analysis of Naturally Fractured Reservoirs" released at the 1998 AAPG Annual Convention in Salt Lake City, Utah is available upon request from NETL.