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Title: Physical property characteristics of gas hydrate-bearing reservoir and associated seal sediments collected during NGHP-02 in the Krishna-Godavari Basin, in the offshore of India

India’s National Gas Hydrate Program Expedition 02 (NGHP-02) was conducted to better understand geologic controls on gas hydrate occurrence and morphology, targeting coarse-grained sediments along the lower continental slope offshore eastern India. This study combines seismic, logging-while-drilling data, and a petroleum system approach to provide a regional geologic and lithologic context for: 1) gas hydrate morphology and distribution, and 2) effects of fine-grained sediments (clays and other grains smaller than 63µm) on gas production in NGHP-02 Area B in the Krishna-Godavari Basin. Area B seismic data show a buried anticline/syncline structure with strong reflectors, R1 and R2, that delineate two of the five lithologic units: Unit I (shallowest), II (R1), III, IV (R2) and V (below the bas of gas hydrate stability). Throughout Area B, gas hydrate morphology depends on its placement within these units. Specifically, core- and grain-scale measurements indicate fines content exerts a primary control on the gas hydrate distribution and morphology. Units I, II and III are generally fine-grained. On the anticline crest, these units host primarily grain-displacing gas hydrate veins linked to pore-occupying gas hydrate in thin, localized, coarser-grained deposits. Diatoms in Unit III increase porosity with depth, reaching ~70% where it contacts Unit IV, themore » gas hydrate reservoir associated with reflector R2. The Unit III lithology and porosity allow fluid and dissolved-phase methane to escape Unit IV and form gas hydrate in the fine-grained overburden. Within Unit IV, fine-grained layers are interbedded with coarser-grained gas hydrate reservoir sands, and the fines content even in the sands is high enough to impact hydraulic and mechanical properties during gas production. Fluid motion during gas production can mobilize fines, which can then clog pore throats, limiting production rates. In conclusion, pore-water freshening during gas hydrate dissociation can increase fines mobilization, particularly given the smectite identified in the fine-grained interbeds.« less
Authors:
ORCiD logo [1] ; ORCiD logo [1] ;  [2] ;  [3] ;  [4]
  1. U.S. Geological Survey, Woods Hole, MA (United States)
  2. U.S. Geological Survey, Menlo Park, CA (United States)
  3. U.S. Geological Survey, Denver, CO (United States)
  4. Oil and Natural Gas Corp., Navi Mumbai (India)
Publication Date:
Grant/Contract Number:
FE0028966
Type:
Accepted Manuscript
Journal Name:
Marine and Petroleum Geology
Additional Journal Information:
Related Information: Jang, J., Waite, F. W., Stern, L. A., Collett, T. S. and Kumar, P. (2018). Dependence of sedimentation behavior on pore-fluid chemistry for sediment collected from Area B, Krishna-Godavari Basin during India's National Gas Hydrate Program, NGHP-02: U. S. Geological Survey data release, https://doi.org/10.5066/P9FXJ1VX.Waite, W. F., Jang, J., Collett., T. S. and Kumar, P. (2018). Grain-size data from India's National Gas Hydrate Program NGHP-02 expedition in the Krishna-Godavari Basin offshore eastern India, 2015: U. S. Geological Survey data release, https://doi.org/10.5066/P97RL4X4.; Journal ID: ISSN 0264-8172
Publisher:
Elsevier
Research Org:
Louisiana State Univ., Baton Rouge, LA (United States)
Sponsoring Org:
USDOE Office of Fossil Energy (FE)
Country of Publication:
United States
Language:
English
Subject:
03 NATURAL GAS; India’s National Gas Hydrate Program; logging-while-drilling; methane gas hydrate-bearing sediments; physical properties; fines characterization
OSTI Identifier:
1474107

Jang, Junbong, Waite, William F., Stern, Laura A., Collett, Timothy S., and Kumar, Pushpendra. Physical property characteristics of gas hydrate-bearing reservoir and associated seal sediments collected during NGHP-02 in the Krishna-Godavari Basin, in the offshore of India. United States: N. p., Web. doi:10.1016/j.marpetgeo.2018.09.027.
Jang, Junbong, Waite, William F., Stern, Laura A., Collett, Timothy S., & Kumar, Pushpendra. Physical property characteristics of gas hydrate-bearing reservoir and associated seal sediments collected during NGHP-02 in the Krishna-Godavari Basin, in the offshore of India. United States. doi:10.1016/j.marpetgeo.2018.09.027.
Jang, Junbong, Waite, William F., Stern, Laura A., Collett, Timothy S., and Kumar, Pushpendra. 2018. "Physical property characteristics of gas hydrate-bearing reservoir and associated seal sediments collected during NGHP-02 in the Krishna-Godavari Basin, in the offshore of India". United States. doi:10.1016/j.marpetgeo.2018.09.027.
@article{osti_1474107,
title = {Physical property characteristics of gas hydrate-bearing reservoir and associated seal sediments collected during NGHP-02 in the Krishna-Godavari Basin, in the offshore of India},
author = {Jang, Junbong and Waite, William F. and Stern, Laura A. and Collett, Timothy S. and Kumar, Pushpendra},
abstractNote = {India’s National Gas Hydrate Program Expedition 02 (NGHP-02) was conducted to better understand geologic controls on gas hydrate occurrence and morphology, targeting coarse-grained sediments along the lower continental slope offshore eastern India. This study combines seismic, logging-while-drilling data, and a petroleum system approach to provide a regional geologic and lithologic context for: 1) gas hydrate morphology and distribution, and 2) effects of fine-grained sediments (clays and other grains smaller than 63µm) on gas production in NGHP-02 Area B in the Krishna-Godavari Basin. Area B seismic data show a buried anticline/syncline structure with strong reflectors, R1 and R2, that delineate two of the five lithologic units: Unit I (shallowest), II (R1), III, IV (R2) and V (below the bas of gas hydrate stability). Throughout Area B, gas hydrate morphology depends on its placement within these units. Specifically, core- and grain-scale measurements indicate fines content exerts a primary control on the gas hydrate distribution and morphology. Units I, II and III are generally fine-grained. On the anticline crest, these units host primarily grain-displacing gas hydrate veins linked to pore-occupying gas hydrate in thin, localized, coarser-grained deposits. Diatoms in Unit III increase porosity with depth, reaching ~70% where it contacts Unit IV, the gas hydrate reservoir associated with reflector R2. The Unit III lithology and porosity allow fluid and dissolved-phase methane to escape Unit IV and form gas hydrate in the fine-grained overburden. Within Unit IV, fine-grained layers are interbedded with coarser-grained gas hydrate reservoir sands, and the fines content even in the sands is high enough to impact hydraulic and mechanical properties during gas production. Fluid motion during gas production can mobilize fines, which can then clog pore throats, limiting production rates. In conclusion, pore-water freshening during gas hydrate dissociation can increase fines mobilization, particularly given the smectite identified in the fine-grained interbeds.},
doi = {10.1016/j.marpetgeo.2018.09.027},
journal = {Marine and Petroleum Geology},
number = ,
volume = ,
place = {United States},
year = {2018},
month = {9}
}