Permeability of methane hydrate-bearing sandy silts in the deep-water Gulf of Mexico (Green Canyon Block 955)

AAPG Bulletin
By: , and 



Permeability is one of the most crucial properties governing fluid flow in methane hydrate reservoirs. This paper presents a comprehensive permeability analysis of hydrate-bearing sandy silt pressure-cored from Green Canyon Block 955 (GC 955) in the deep-water Gulf of Mexico. We developed an experimental protocol to systematically characterize the transport and petrophysical properties in pressure cores. The in situ effective permeability ranges from 0.1 md (1.0 × 10−16 m2) to 2.4 md (2.4 × 10−15 m2) in these natural sandy silts cores with hydrate occupying 83%–93% of the pore space. When hydrate dissociates from these cores, the measured intrinsic permeability (k0) is 0.3 md (3.0 × 10−16 m2) to 9.3 md (9.3 × 10−15 m2); these results are affected by fines migration during hydrate dissociation. We analyzed samples reconstituted from these sandy silts and found k0 to range from ∼12 md (∼1.2 × 10−14 m2) to ∼41 md (∼4.1 × 10−14 m2). The water relative permeabilities (krw) of GC 955 pressure cores are large relative to other natural pressure cores from offshore Japan, offshore India, and onshore Alaska. These krw values are also higher than predicted by current conceptual relative permeability models where hydrate fills the pores or coats the grains of the sediments. This fundamental conundrum requires further study. Our work provides essential parameters to reservoir simulation models seeking to predict hydrate formation in geological systems, evaluate the gas production potential, and explore the best way to produce this energy resource in sandy silt reservoirs.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Permeability of methane hydrate-bearing sandy silts in the deep-water Gulf of Mexico (Green Canyon Block 955)
Series title AAPG Bulletin
DOI 10.1306/08102121001
Volume 106
Issue 5
Year Published 2022
Language English
Publisher American Association of Petroleum Geologists
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description 30 p.
First page 1071
Last page 1100
Country United States
State Louisiana
Other Geospatial Green Canyon Block 955, Green Knoll, Gulf of Mexico
Google Analytic Metrics Metrics page
Additional publication details