Gas Hydrats


Ajit Kumar AJIT KUMARWISDOM IAS, New Delhi.

Gas hydrates are crystalline form of methane and water, and exist in shallow sediments of outer continental margins. They are envisaged as a viable major energy resource for future. Thus, delineation of gas-hydrates by geophysical methods is very important for evaluating the resource potential along the Indian continental margin with a view to meet the overwhelming demand of energy for India

Gas hydrates with their abundant resource potential is emerging as a potential fuel resource. The preliminary assessment of geological condition and limited available seismic data suggests high possibility of occurrence of large quantity of gas hydrates within the EEZ of India. The multi‐channel seismic data collected by various organisations during the last Plan period has been evaluated and based on the data, two promising sites of 100 km x 100 km in the Krishna‐Godavari (KG) and the Mahanadi basins have been identified and surveyed.. During the XII Plan period, it is proposed to focus the studies on ground-truthing and the quantification of the resources at these two sites as well as to explore for similar occurrences in other potential areas of the Indian EEZ With an estimated amount of trillions of cubic metres of methane gas available in the Gas Hydrate deposits in the Indian waters,

Gas Hydrates can be the future source of energy for India. Development of technology to harvest Gas Hydrates can ensure energy security of the nation. Gas Hydrate exploration, development of tools for the environmentally safe recovery of gas from these gas hydrates is the need of the hour.
Basic infrastructure to take up studies on Gas Hydrates in India has been set in three collaborating National laboratories in India and expertise was gained during the 10th and 11th plan activity. In the present day energy demand with the increase in crude oil price, gas hydrates is one of the promising alternate viable resources and is a long term prospect.

Exploitation of gas hydrates from continental margins of ocean basins is a technological challenge. In the international scenario, a proven field executable methodology for the exploitation is yet to be established, but lots of laboratory scale experimental works are in progress for safe exploitation. Krishna-Godhavari basin has evidence of occurrence of huge thickness of gas hydrates demonstrated by shale fracturing mechanism and world’s deep seated occurrence of gas hydrates have been sampled in Andaman basin. To prove the developed concepts and technology from the capacity building which happened during 10th and 11th plan period, taking up this program is beneficial.

a) Objectives

1.     Quantification of gas hydrates reserves using Multi Channel Seismic (MCS) & Ocean Bottom Seismometer (OBS) data from Krishna Godavari and Mahanadi basins
2.     Collection of geophysical and geological data at new potential locations
3.     Demonstrate existence of methane hydrate by ground truth sampling/drilling at the identified potential sites
4.     Establish laboratory scale experimental and numerical studies to establish the feasibility of methane recovery from gas hydrates
5.     Conduct field trials at potential gas hydrate site for environmentally safe recovery of gas from gas hydrates
6.     Understand the impact of gas hydrates dissociation on geological environment and climate and establish mechanism for monitoring and management of environmental perturbation during harvesting of gas hydrate

b) Participating Institutions:
1.     National Institute of Ocean Technology, Chennai
2.     National Centre for Antarctic & Ocean Research, Goa
3.     National Geophysical Research Institute, Hyderabad.

c) Implementation Plans:
During the 12th plan stress will be on the numerical studies, laboratory and field experiments towards the extraction gas from the gas hydrates
Using the technologies developed earlier ground truthing & validation of occurrence and abundance of gas hydrates will be carried out
New sites will be identified and explored for the gas hydrates
Technology development for the exploration and methane generation experiments from gas hydrate will be carried out by NIOT. Science component will be carried out by National Geophysical Research Institute (NGRI), Hyderabad and National Institute of Oceanography (NIO), Goa. Science component will be coordinated by National Centre for Antarctic Ocean Research (NCAOR), Goa. Scientific data collected by NGRI and NIO will be deposited at NCAOR, Goa. NGRI and NIO would be continuing its concentration on the scientific aspects of the gas hydrates while the technological tool development would be implemented by NIOT based on the input and requirement of NIO and NGRI and vice versa
Infrastructure facilities / lab requirements
It is proposed to have a Test beds for carrying out the testing of the systems developed for Gas Hydrates program. The Autonomous Coring System is of dimensions 8 X 3 X 6 m and weight is 10 tons in air. Infrastructure would enable testing of such systems.
d) Deliverables:
The most significant output from this program would be a comprehensive understanding of the gas hydrate occurrences in the Indian EEZ. In addition, the program also envisages development of suitable technology for methane generation experiments from the proved locations of gas hydrate occurrences,
1.     Study of attenuation, reflection strength, blanking and instantaneous frequency for qualifying whether the BSR is related to gas-hydrates or identifying gas-hydrates without BSR
2.     Pre-stack depth migration of MCS data to produce improved structural image sediments including the BSR, base of free-gas layer and migration paths for fluid flow
3.     Traveltime tomography of MCS and OBS data for delineating the extension of gas-hydrates/'free-gas' bearing sediments
4.     Fine-scale and accurate velocity structure using full-waveform inversion of MCS data across the BSR
5.     Detection of fracturing and potentially delineating the reservoir type (fractured vs. pore space) from the analysis of 4-C OBS data
o    Field trials at potential gas hydrate sites for environmentally safe recovery of gas from gas hydrates.
o    Quantification of gas hydrates reserves using Multi Channel Seismic (MCS), and Ocean Bottom Seismometer(OBS).
o    Experimental and numerical studies to establish the recovery of Methane from gas hydrates.
 



Saturday, 25th Feb 2017, 01:08:13 PM

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