Abstract
Well tests are often used to investigate reservoir heterogeneities such as fractures, conductivity of faults, and matrix permeability. Attributing a measured pressure response to a particular geological feature is problematic, as many different solutions will fit the same pressure response. Data integration is the key to understanding well pressure transients and the underlying geology controlling them.
A recently acquired and interpreted 3D seismic survey indicated the reservoir contained numerous strike slip faults. To reduce the uncertainty associated with reservoir characterization, a multidisciplinary team comprising of geophysicists, geologists and reservoir engineers selected an area of the reservoir to focus their efforts. The integration of the 3D seismic with dynamic data provides a possible means of validating the interpretation.
Anomalous transient pressure data were identified on five wells. Initial interpretations proved ambiguous with several possible geological reasons. Close examination of the 3D seismic data indicated in each case the presence of a fault. Faults were found to be the likely structural anomalies that have been detected by seismic and well test data. The fault throw, conductivity and its distance to the wellbore were estimated. The transient pressure data enabled us to evaluate the faults as sealing.
Once the integration perception was adopted, and high quality data became available, concerns with the 3D seismic interpretation data and the uncertainties associated with pressure transient data that were initially ambiguous began to make sense.
