T92 Geology and Geochemistry of Carbon Dioxide, Helium, and Other Low-BTU Natural Gas Systems

Monday, 26 September 2016
8:00 AM - 12:00 PM
Room 506

EVALUATING THE GEOLOGY AND GEOCHEMISTRY OF HELIUM, CO2, AND LOW-BTU HYDROCARBON RESERVOIRS IN THE CRUST

Paper number: T92-10
Program: Technical Sessions
Time: 10:05 AM – 10:20 AM

Authors

Abstract

Throughout the last several decades, low-BTU natural gas fields, including natural gases rich in CO2, helium, and nitrogen, have become critically important economic natural gas deposits in the US and abroad. For example, the use of carbon dioxide for enhanced oil recovery (EOR) has revitalized U.S. domestic oil production, while investigations of their occurrence are important analogs for the potential storage of anthropogenic CO2. Similarly, anthropogenic demands for helium in the medical, nanotechnology, and defense industries have increased precipitously in recent decades amid a decreased commitment to the US Strategic Helium Reserve. For these reasons, there has been a renewed interest in previously overlooked natural gas deposits that are rich in low-BTU natural gases, specifically CO2 and helium in recent years.

Much of the previous work on low-BTU natural gases has established a relationship between the introduction of volcanic or geothermal fluids and the occurrence of natural gas reservoirs with elevated CO2 and helium contents. The principal factors for predicting the discovery of these deposits, in addition to the availability of suitable seals and structural or stratigraphic traps, are establishing the relative timing of natural gas emplacement, the mechanisms and dynamics of fluid migration, and the associated compendium of gas-water-rock interactions that typically reduce the volume of CO2 via trapping and increase the release of helium from minerals in the crust by metamorphism. Herein, we will review the state-of-the-art in gas compositional analysis and geochemistry of established and emerging low-BTU natural gas deposits in the continental US. We will focus on recent developments in noble gas and isotope measurements, interpretation, and numerical modelling that have helped constrain the source of low-BTU natural gases, the timing and mechanisms of natural gas migration from source to emplacement, and the interaction of gas with water and rocks in the crust. In combination with other traditional petroleum geology and structural/tectonic analysis, this data will provide a perspective on the search for these increasing economically relevant low-BTU natural gas reserves.

Geological Society of America Abstracts with Programs. Vol. 48, No. 7

doi: 10.1130/abs/2016AM-287722

© Copyright 2016 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.