Luncheon – September 17, 2004

Title: Production-History Characteristics of a Naturally Fractured Reservoir
Speakers: Dr. Connie Knight and Dr. Jennifer Miskimins, Colorado School of Mines
Publication: The Outcrop, September 2004, p. 4

The North La Barge Shallow Unit (NLBSU) produces from the Mesaverde Formation at depths of 2,000 ft (610 m). The NLBSU exhibits four types of production behavior including: fracture-dominated, matrix-dominated, fracture/matrix combination, and significantly reduced production near faults. The fracture-dominated production behavior is centralized in a structurally complex, highly stress-controlled region, which includes a horsetail splay termination of a strike-slip fault. This faulted region results in critically stressed natural fracture production.

Faults play a dual role in controlling production histories at the NLBSU. In addition to understanding critically stressed natural fracture production, fault parallel jointing is recognized as enhancing production performance. However, several producing wells that were drilled in fault damage zones exhibit significantly reduced production performance. The presence of fault damage zones takes precedence over the occurrence of natural fractures in terms of reservoir enhancement and results in poor production performance.

Knowledge of these types of production controls can aid in reservoir management throughout the life of a field.