Date of Award

2019

Document Type

Campus Access Master's Report

Degree Name

Master of Science in Geophysics (MS)

Administrative Home Department

Department of Geological and Mining Engineering and Sciences

Advisor 1

Roohollah Askari

Committee Member 1

Roger Turpening

Committee Member 2

James DeGraff

Committee Member 3

Mir Sadri-Sabet

Abstract

On the shelf and slope regions off of the northern Gulf of Mexico coast, salt dome structures have resulted in significant amounts of petroleum accumulation relative to other trapping mechanisms in the region. Due to their abundance and relatively low exploration risk, salt-dome-style traps have been paramount to the Gulf’s petroleum industry over the last 80 years. It is therefore important that these domes be studied to determine how salt movement through time and space influences hydrocarbon migration and entrapment. This field study focuses on the salt dome at the Eugene Island (EI) 205 lease block. Though exhibiting a similar developmental history, EI 205 has produced approximately 75% less crude oil relative to adjacent domes based on present day crude oil production totals.

The objective of this study was to determine the cause of this discrepancy by determining whether reduced accumulation at EI 205 was a result of variable reservoir properties, or historic salt and hydrocarbon migration through differential spatial deformation. New full-azimuth nodal (FAN) 3D seismic depth data with supporting time domain data were primarily used in this study, along with well log, sidewall core, paleontological and production data. By mapping interval thickness between paleontological time horizons as well as fault networks, it was concluded that the reduced oil production at EI 205 resulted from EI 205 having experienced significantly less faulting, and consequently less hydrocarbon migration, relative to adjacent salt domes. Additional deformational events that affected adjacent salt domes allowed for higher rates of oil migration into their respective traps, whereas the initial low migratory rate of oil and lower intensity of deformation at EI 205 resulted in most of its oil remaining in deeper reservoirs.

Available for download on Friday, May 01, 2020

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