Characterization of Fractured Reservoir Block Size Using Microcrack
E. Laubach and Jon
E. Olson (Department of Petroleum and Geosystems Engineering,
The University of Texas at Austin), principal investigators; assisted
by Yuan Qiu, Zeno Philip, and Jon Holder
goals of this project, funded by the Advanced Research
Program of the Texas Higher Education Coordinating Board,
included characterization of fracture arrays in sedimentary
rocks, relating the fracture characteristics to fluid-flow
observations, and relating fracture characteristics to
the bedding architecture of the sedimentary rocks. Naturally
fractured reservoirs represent a large but poorly understood
resource in the State of Texas as well as in other hydrocarbon-producing
provinces throughout the world. Reservoir-scale fracture
networks are difficult to characterize because fracture
spacing is typically many times the diameter of a conventional
borehole, so that in most cases well bores miss fractures.
Because these fractures may nevertheless profoundly influence
reservoir behavior, this sampling problem poses a serious
challenge to fracture characterization and simulation.
This project involved geomechanical modeling and other
advanced modeling and characterization methods to improve
attributes in the interwell region. The project successfully
used microstructural fracture proxies to define the location
of horizons having conductive fractures on a scale suitable
for use in reservoir simulation. These results have been used
to specify the vertical dimension of simulator cellblocks.
Geomechanical modeling, calibrated with subsurface fracture
observations and new rock property tests, specifies the spacing
of fracture clusters in a way that can be used to define the
lateral extent of cellblocks.
Olson, J., Hennings, P. H., and Laubach, S. E., 1998, Integrating
wellbore data and geomechanical modeling for effective characterization
of naturally fractured reservoirs: EUROCK '98, Society of Petroleum
Engineers, p. 475485.
E., 1997, A method to detect natural fracture strike in sandstones:
American Association of Petroleum Geologists Bulletin, v. 81, no.
4, p. 604623.
|For more information,
please contact Steve Laubach, principal investigator. Telephone 512-471-6303;