Hydrocarbon Vision 2030 (ஹைட்ரோகார்பன் தொலைநோக்கு ஆவணம் 2030)

The survey area mainly comprises of three blocks, namely, Block-1, 2 and 3. The area includes the
acreages held by ONGC as well as adjoining open acreages. The details about the blocks are as
follows:
Block
Name of the area
Approx. LKM
1 Sector-VC:
Banaskandi ML, Cachar Dist. PML and AA-94/1 (Assam,
Manipur & Mizoram)
7351LKM
Grid: 500m x 5000m
2 AA-ONN-2001/2 (Assam, Mizoram) 4722 LKM
Grid: 500m x 5000m
3 ML areas- Namti, Geleki, Geleki-Extn, SE-Geleki, and SE-
Geleki Extension (Assam, Nagaland)
322 LKM
Grid: 500m x 2500m
Total LKM 12395
The above areas are largely mountainous, typical elevations from mountain top to valley ranges from
50 to 1,000m, rugged terrain with jungle cover and sparse population.
AEM-PTP passive source electromagnetic method
Electromagnetic methods provide cheaper means of supplementing seismic data. These methods
respond to resistivity contrast of the formations unlike seismic, which respond to acoustic impedance
contrast. FTB regimes often have thin high velocity near surface layers, which acts as an acoustic
barrier whereas EM methods yield better results. "Audio electro magnetic passive transient impulse
(AEM-PTP)” is a passive source transient electromagnetic prospecting technique based on detection
of transients of secondary electromagnetic field associated with upward fluid flow associated with
REDOX activity. It is a proprietary technology of Pinemont, a subsidiary of McPhar International Ltd.
In June 2015, representatives from Mcphar international presented the Pinemont AEM-PTP survey
techniques at ONGC, Jorhat. Following positive feedback and subsequent discussions, McPhar has
given a proposal to undertake a test survey over a small block, covering approximately 100 sq km.
Passive seismic tomography
Passive seismic tomography involves listening to the earth passively over time and using it to derive
subsurface information. P and S-wave travel times help in understanding structural configuration of
the subsurface and Vp/Vs provides lithological information. Passive seismic tomography has already
been deployed in Sector VC and survey completed in November, 2011 and data delivered as per the
deliverables by M/S Land Tech Enterprises. The survey resulted in:
1. Vp/Vs values that helped in demarcating sand prone areas
2. PST velocity field, which were used in reprocessing of a few 2D lines and 3D volume in the area to
see any possible improvement.
5.1.4.2 Enhancing exploration activities
(i)
Conversion of 2P to 1P reserves
The term 2P is used to denote the sum of proved and probable reserves and 1P is frequently
used to denote proved reserves. The best estimate of recovery from committed projects is
generally considered to be the 2P (sum of proved and probable reserves). However, probable
reserves are lower categories of reserves, commonly combined and referred to as “unproved
reserves,” with decreasing levels of technical certainty. Probable reserves are volumes that are
defined as “less likely to be recovered as proved, but more certain to be recovered than possible
reserves”.
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