Page 124 - DGH_Annual_Report

124 INDIA'S HYDROCARBON OUTLOOK 2024-2025

7 7.1 Introduction:

Unconventional energy resources refer to sources
of energy that are extracted and produced using
methods that differ from traditional fossil fuel
extraction. Unconventional resources exist in
petroleum accumulations that are pervasive
throughout a large area and are not significantly
Unconventional affected by hydrodynamic influences (also called
“continuous-type deposit”). These resources are
Petroleum often more challenging to develop and require
advanced technology and techniques. Key
unconventional energy resources include:
Resources 7.1.1 Coal Bed Methane (CBM):

During the process of coalification or thermal
maturation of coal beds, valuable quantities of
hydrocarbon gas get accumulated, primarily
in the adsorbed state. CBM is considered a
cleaner energy source compared to coal, as its
combustion produces less carbon dioxide and
other pollutants. It is extracted by reducing the
pressure within the coal seams through water
pumping, which releases the adsorbed methane
gas.
There are four types of terms used to describe
the methane emanating from coal beds:
a. Coalbed Methane (CBM) or Coal Seam Gas
(CSG) - A generic term for the methane-
rich gas naturally in coal seams typically
comprising 80% to 90% methane with lower
proportions of ethane, propane, nitrogen,
and carbon dioxide. In international use,
this term refers to the methane recovered
from unmined coal seams using surface
boreholes.