Subsurface fracture spacing
- Sandia National Labs., Albuquerque, NM (USA)
- CER Corp., Las Vegas, NV (USA)
This study was undertaken in order to document and analyze the unique set of data on subsurface fracture characteristics, especially spacing, provided by the US Department of Energy's Slant Hole Completion Test well (SHCT-1) in the Piceance Basin, Colorado. Two hundred thirty-six (236) ft (71.9 m) of slant core and 115 ft (35.1 m) of horizontal core show irregular, but remarkably close, spacings for 72 natural fractures cored in sandstone reservoirs of the Mesaverde Group. Over 4200 ft (1280 m) of vertical core (containing 275 fractures) from the vertical Multiwell Experiment wells at the same location provide valuable information on fracture orientation, termination, and height, but only data from the SHCT-1 core allow calculations of relative fracture spacing. Within the 162-ft (49-m) thick zone of overlapping core from the vertical and deviated wellbores, only one fracture is present in vertical core whereas 52 fractures occur in the equivalent SHCT-1 core. The irregular distribution of regional-type fractures in these heterogeneous reservoirs suggests that measurements of average fracture spacing'' are of questionable value as direct input parameters into reservoir engineering models. Rather, deviated core provides data on the relative degree of fracturing, and confirms that cross fractures can be rare in the subsurface. 13 refs., 11 figs.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- Sponsoring Organization:
- DOE/FE
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 6306790
- Report Number(s):
- SAND-90-3018C; SPE-21877; CONF-9104121-1; ON: DE91005118
- Resource Relation:
- Conference: 1991 Society of Petroleum Engineers (SPE) joint Rocky Mountain regional meeting and low permeability reservoir symposium, Denver, CO (USA), 15-17 Apr 1991
- Country of Publication:
- United States
- Language:
- English
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