ÇAĞRILI KONUŞMALAR / KEYNOTES Invited Speeches ... - TPJD

Well Test Analysis in the Presence of Carbon Dioxide in Fractured Reservoirs
Tuğçe Bayram, Serhat Akın
Middle East Technical University, Department of Petroleum and Natural Gas Engineering,
Ankara
Carbon-dioxide injection for enhanced oil recovery and/or sequestration purposes has gained
impetus in the last decade. It is known that well test analysis is important to get information
about reservoir properties, boundary conditions, etc. Although there are some studies related to
the well test analysis in the fracture reservoirs, most of them are not focused on the injection of
the carbon dioxide into the reservoir. 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. In this study, effects of fractures
(geometry, orientation, flow properties) on pressure and pressure derivative behavior are studied
by applying a reservoir simulation model. Multiphase flow effects in CO2 flooded fractured
reservoirs are observed. Several runs are conducted by changing the aforementioned properties
in the CO2 flooded reservoir. Results are analyzed by usage of various analytical methods.
219