Application of Salt Tectonics Concepts to Hydrocarbon Exploration in Mexico

Abstract

Abstract

Over the last 20 years, industry has invested significant resources toward improving understanding of salt tectonic processes and their impact on hydrocarbon systems. This study gathers examples from salt basins around the globe, identifies key findings and their influence on play elements, and summarizes best practices for effective salt interpretation.

This investigation leverages global 3D seismic datasets, which have evolved in quality with the advent of pre-stack depth migration and wide azimuth acquisition. Drilling results from salt basins help constrain the seismic interpretations. Field mapping studies reveal complexities of the salt-sediment interface, at a sub-seismic scale, that are often critical to salt-flank prospects.

Stratigraphic and structural components of salt systems are interrelated. Sedimentation can generate differential loading, an effective mechanism for driving salt withdrawal and inflation. In turn, the resulting paleotopographic highs and lows help direct sand systems through a salt basin. Concepts such as onlap, offlap, and halokinetic sequences are critical in helping an explorationist discern traps where sands are likely high on structure from those that are less prospective.

A salt architectural framework involves the identification of top and base of allochthonous salt, canopy sutures, welds, and salt ascension zones from the mother salt level, which must be interpreted in an internally consistent manner capable of explaining salt emplacement and evacuation over time. Once completed, a salt architectural framework is an effective tool for predicting sub-salt sediment fairways, EOD's, and defining structural domains and likely sub-salt trap types.

Integrated geologic-geophysical solutions are critical in salt provinces, and involve early geologic interpretation during construction of PSDM velocity models, and later understanding of geophysical imaging issues during geologic interpretation of the final product. As a result, salt tectonics experts should be involved in picking the velocity model during processing, and interpreters of the final product need to have an appreciation of the processing, as well as concepts such as illumination, migration algorithms, and acquisition geometry.

Thanks to a sound understanding of salt tectonic process and their impact on hydrocarbon systems, industry should be well-positioned to apply these best practices and global insights to Mexico's relatively under-explored salt basins.

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