Use of Seismic Geomorphology to Re-define Mature Fields: Application of Spectral Decomposition and Neural Networks to 3D Examples from Canada and Colombia

Mustaqeem, Azer¹ and Baranova, Valentina
¹[email protected]

The field development and recovery from new fields need better definition of the field boundaries. The geological maps drawn for the reserve estimates do not usually use seismic input. In the past, the reasons were quite obvious that seismic data did not provide hard reservoir numbers with accuracy. This led to over simplified models of the reservoir with incorrect production estimates.

During last 10 years the seismic reservoir characterization methods such as spectral decomposition, neural networks and deterministic inversion have progressed to the extent where they can re-define the field boundaries and bring out the geomorphology and even diagenesis of the reservoir rocks. Numerous studies from geologists and geophysicists alike have shown by example the benefits of using seismic information for stratigraphic details.

For this study, seismic frequencies and amplitudes are used to create high resolution reservoir thickness and facies maps while the well data is used to constrain them. Within the Deep Basin of Alberta the Cretaceous fluvial section is very tight with prolific high porosity reservoirs trapped between very low permeability sand and shale. During the exploitation, many thinner porosity segments are not perforated due to the understanding that the completion in the thicker zone will drain the full extent of the formation, which is not the case. Practically those thinner segments remain un-drained and have the potential to add new reserves within the existing mature fields.

From the study of mature fields in WCSB the seismically defined model is then also applied to few fields in Llanos and Putumayo basins of Colombia. It is shown by examples that the application of integrated seismic reservoir characterization early in the development can enhance the production and can provide better forecasting of reserves.

AAPG Search and Discovery Article #90166©2013 AAPG International Conference & Exhibition, Cartagena, Colombia, 8-11 September 2013