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7th Middle East Geosciences Conference and Exhibition
Manama, Bahrain
March 27-29, 2006
Simulation
to Evaluate Fracture Flow Potential in a Tight
Reservoir
in
Kuwait
1 Baker Atlas Geoscience, Baker Hughes, PO BOX 8786, Abu Dhabi, United Arab Emirates, phone: 971506410949,
[email protected]
2 Kuwait Oil Company, Kuwait City
2 Baker Hughes, Bahrain
A horizontal well was drilled to evaluate fracture flow potential of a tight reservoir
, which intersected top three units of the
reservoir
. Borehole image logs show that the uppermost unit has 3-5 ft thick brittle highly fractured layers. The other two
units are ductile with 3-5 inch thin brittle fractured beds. The middle unit has good porosity, but matrix permeability is low in
all units.
A single well dual porosity simulation
was performed to validate findings from borehole image logs regarding flow potential
of fracture corridors, faults and layer-bound fractures. The basic geological model is taken from the work on borehole image
logs. The geological interpretation shows one major and a few minor fracture corridors. These were explicitly represented in
the
simulation
models.
The fundamental conclusion from the simulation
study
is that without fractures it is not possible to achieve history match for
the observed matrix permeability values. One or two major fracture corridors are sufficient for history match. The rate of
pressure and production decline is much steeper for the
simulation
model than the observed decline rates. This suggests
that some additional agents of high permeability are required, such as high matrix permeability or fractured layers with
interconnected fractures. The stochastic fracture model shows that fractures are within sub-percolation range and fractures
occur as clusters but not as a totally interconnected network of infinite extent. It is also possible that the fractured layers
have lenticular shapes with finite lateral extension.