Benefits From Integrating Seismic and Non-Seismic Data for Offshore Mexico Exploration: From Regional Geological Context to Prospect Imaging and Reservoir Characterization

Abstract

Abstract

The positive contribution of non-seismic methods, electromagnetic (EM), and potential field (PF), as complements to seismic data for hydrocarbon exploration and production workflows is a widespread concept. Their use is limited in practice, however, as it requires us to design workflows tailored to different geological settings. Integrating seismic and non-seismic data requires specific numerical tools to extract information from multiple measurements and a multidisciplinary team with experts capable of using and mitigating, respectively, benefits and limitations. However, when these ingredients are available, the complementary information EM and PF data provide is of huge value, especially in areas with complex geology (e.g. salt) or in areas with limited information available to explorers.

We present different ways to integrate seismic, PF and EM data from understanding the regional tectonics, through the challenges posed to seismic imaging by complex 3D geology and the presence of salt, to estimating reservoir petrophysical quantities at appraisal phase.

At the first stage, satellite PF data are blended with local datasets (shipborne or airborne) to provide a large-scale tectonic framework, exploiting the density and magnetic property contrast between basement and the units above. Basement and Moho are extracted in depth via an iterative inversion, possibly using a priori information.

The next step is to reduce the data by removing the estimated regional trends to focus on the upper part of the section. Subsequent steps depend on the exploration phase; in frontier areas (few wells, sparse 2D seismic data), PF data are modeled in 3D, calibrated with available information, and then extended into areas with no information. Subsequently, the use of a simultaneous joint inversion enables a 3D velocity model building approach when only a 2D seismic grid is available, benefitting the presence of 3D gravity data to control the space between lines. In areas where well and 3D seismic data are available, gravity, gravity gradiometry or EM data can also be jointly inverted to update velocity, to resolve imaging issues combining the sensitivity to salt geometries of all these methods.

Once imaging is considered to be of sufficient quality and drilling results are available, seismic data and EM can be inverted with a petrophysical joint inversion to estimate reservoir properties, thereby reducing the uncertainty on fluid saturation estimates for the delineation phase.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016