Naturally fractured reservoirs (NFR) represent an important percentage of the worldwide
hydrocarbon reserves and production. Reservoir simulation is a fundamental technique
in characterizing this type of reservoir. Fracture properties are often not available due to
difficulty to characterize the fracture system.
On the other hand, well test analysis is a well known and widely applied reservoir
characterization technique. Well testing in NFR provides two characteristic parameters,
storativity ratio and interporosity flow coefficient. The storativity ratio is related to
fracture porosity. The interporosity flow coefficient can be linked to shape factor, which
is a function of fracture spacing.
The purpose of this work is to investigate the feasibility of estimating fracture porosity
and fracture spacing from single well test analysis and to evaluate the use of these two
parameters in dual porosity simulation models.
The following assumptions were considered for this research: 1) fracture
compressibility is equal to matrix compressibility; 2) no wellbore storage and skin
effects are present; 3) pressure response is in pseudo-steady state; and 4) there is single
phase flow. Various simulation models were run and build up pressure data from a producer well
was extracted. Well test analysis was performed and the result was compared to the
simulation input data.
The results indicate that the storativity ratio provides a good estimation of the magnitude
of fracture porosity. The interporosity flow coefficient also provides a reasonable
estimate of the magnitude of the shape factor, assuming that matrix permeability is a
known parameter. In addition, pressure tests must exhibit all three flow regimes that
characterizes pressure response in NFR in order to obtain reliable estimations of fracture
porosity and shape factor.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/3337 |
| Date | 12 April 2006 |
| Creators | Perez Garcia, Laura Elena |
| Contributors | Schechter, David S. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 2282636 bytes, electronic, application/pdf, born digital |
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