Mapping of Basement Through Magnetic Depth Estimation Along Regional Lines, Southeastern Mexico

Abstract

Estimation of depth and geometry of basement is important on defining sedimentary thicknesses, it helps to understand the tectonic-structural framework of the basin and it represents one essential input data for petroleum system modeling. There are a few basement maps available on the area that provides overall valuable information, however some parts of these maps require to be updated and improved in order to obtain a more precise depth estimation and configuration. 2D basement depth estimation of regional lines at Southeastern Mexico was performed using Total Magnetic Intensity data as main input. Qualitative interpretation of magnetic and gravity data allowed to trace and select 22 regional lines to be depth estimated. Werner and Euler algorithms were used for magnetic source depth estimation. Existing depth horizons were extracted along these lines and used as constraints for basement top configuration. Interpolation of depth estimated values along these lines gave the final basement map. Two of the lines were forward modelled as a quality control for the map. The basement deeper zones were estimated between 12 y 13.5 km to the Southwest, while shallower zones were about 7.5 km at Southern and Northeastern parts of the map. A possible change of basement composition was detected with modeling and depth estimation. Depths obtained were mostly shallower than depths from previous maps, which match better the petroleum systems hypotheses. Zones with big thickness of sediments were identified and can be related to prospective areas. The resulting map can be used in future basin and petroleum systems studies, as well as a starting model for additional detailed local basement modeling and mapping. This work presents a fast and efficient methodology to obtain a regional basement map using basic input data in a big study area, combining non-seismic methods with previous regional interpretation.

AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017