Petrophysically-Constrained Simultaneous Inversion and Interpretation of a Deepwater Gulf of Mexico Field
C. Zhou and T. Smith
Event name: 68th EAGE Conference and Exhibition incorporating SPE EUROPEC 2006
Session: Exploration Case Histories
Publication date: 12 June 2006
Organisations: SPE, EAGE
Info: Extended abstract, PDF ( 947.16Kb )
Price: € 20
In an effort to extract reliable density data from pre-stack seismic data, a new seismic inversion process has been developed that simultaneously solves for density (ρ), P impedance (Ip), and S-impedance (Is). Because all three parameters are linked and solved for simultaneously in this process, this type of inversion is referred to as a dependent inversion; that is, each term is consistent with the other two terms. Conventional inversion techniques independently solve for these three parameters, and the resultant density may or may not be internally consistent.
In addition to a better inversion algorithm, this process also utilizes petrophysical data to put constraints on the relationship(s) between velocities and density. The petrophysical data is also used to better constrain the porosity, allowing a more robust estimation of water saturations from the inverted density volume.
This new technique is applied to a deepwater Gulf of Mexico field, where conventional analysis of both pre- and post-stack seismic data proved to be problematic. This analysis allowed for reservoir fluids to be more accurately predicted. However, evaluation of the seismic data also shows the reservoir to be more discontinuous and complex than previously thought.