PRESENTED BY- ARIHANT JAIN

ARPIT BENJWAL

KOMAL AGARWAL

MANSOOR ALAM KHAN CHOWDHURY

SHALE GAS IN INDIA

What is shale gas ???

Unconventional natural gas produced from shale,

Shale acts as source, reservoir & cap rock for the natural gas,

Characterized by very less permeability & moderate porosity,

Lower uncertainty in resource/reserve determination,

95.5% Methane, 2.5% Ethane, 0.2% Propane,

Large Domestic Source of energy.

Characteristics of shale gas deposits

Mature petroleum source rocks

Usually thermo genic

Very good natural gas in-place volumes

Rich in Organic Matter (TOC=0.5-25%)

Low in Permeability (K= 0.01md or less).

Shale intervals with HGHR - high organic carbon content- most productive.

POLICING THE POLICY

India’s current gas demand is limited by its access to gas supplies based on domestic production and imports availability.

According to the current policy, the oil companies in India are allowed to produce only conventional oil and gas from their exploration blocks. A separate bidding round is required for the unconventional sources, as these are considered unwarranted windfall.

Oil companies, while drilling for oil, have hit thick seams of coal and shale, but do not show interest in testing because they are not allowed to do so.

Some of the imperative considerations are. • A policy that allows oil companies drilling for conventional oil and natural gas to investigate and produce shale gas & Coal bed methane along with natural gas. This change might revive old wells which have been declared as commercially not viable and also increase the energy capacity of the country. • A robust shale gas policy should be in place before awarding the blocks. Speculative Seismic exploration should be done to identify high potential shale gas blocks. • Market driven gas pricing model• The government assistance to public and the private sector companies in importing the shale gas technology to India by providing incentives.

PROSPECTIVE SHALE GAS DEPOSITS IN INDIA

Huge shale deposits in basins of Gondwana, Cambay, Assam- Arakan, KG, Cauvery, Rajasthan:

Damodar valley

- Barren Measures Formation (TOC 6 to 11.0%) in the Gondwana basins.

Cambay shales - (TOC ~ 14.3%) in Gujarat.

KG Basin

- Bhuvanagiri Formation ((TOC ~ 3-5% & permeability ~ 0.033mD) & Raghavpuram shales Cauvery Basins

- Mandapeta (K=0.01mD, TOC ~ 12.8%), Andimadam & Sattapadi shales (TOC ~ 3-8%). In Rajasthan (TOC up to 4.99% in Baisakhi-Bhadasar Formation, Jaisalmer basin).

in Assam- Arakan Basin Disang, Kopili, Disang & Barail Coal Shale in Assam Bokabil & Bhuban Shales in Tripura

Why Gondwana ???

The Gondwana sediments are more matured & occur at shallower depth

The Barren Measure has organic rich shales having TOC = 8-10%, VRo= 0.8, Tmax= High, Kerogen Grade-III

Shale of Barakar Formations are also organic rich

Cluster Analysis or Tight Rock Analysis (TRA)-high organic rich silty shale band of 150-200m in Barren Measure as against a 100-120ft & 170ft of similar kind of organic rich bands in Barnet Shale & Marcellus Shales respectively.

Geochemical data : Barren Measure Shale section of Damodar Valley - bottom 200m above Barakar as most matured, organic rich & may be gas prone).

Due to shallower occurrence of Shales Hydro frac jobs or horizontal wells would also be easier & cheaper – hence techno-economically more viable.

Availability of large amount of water for HF in this part is much easier as discharged water from mines, CBM wells & other huge water bodies are available in plenty.

There is scope of recycling the released frac water for reuse in other wells after a little chemical treatment, as development/production wells are drilled at a space of 10 acres.

Why Cambay Basin ??? The OCS in Cambay Basin : organic rich dark grey shales : TOC

= 0.7-14.25%, VRo= 0.8, Tmax= High (437-453’C), Kerogen Grade-II & III: Matured shale with maximum source potential

Availability of abundant source rock data & other data

Maximum availability of Infra structure facilities

More than 5000 wells drilled - 200 wells through Cambay Shales

Prospectively may be better than many famous gas rich global shales

1 or 2 operators already reported gas production from Cambay Shale .

Various lows from NW to SE & North to South of the basin appear to offer Different type of plays

Why KG Basin ???

Source rock HC potential is generated in Gondwana, Mesozoic & Tertiary Sediments.

Maturity data of effective source rocks indicate right kind of Geochemical data for Shale Gas Resource Assessment.

Data of TOC, VRo, S1, S2 peaks, HI, OI, Tmax etc. from a few selective wells of KG Basin prove that HCG values from Shales give a good indication of Shale Gas potentiality in Mesozoic shales.

MethodologyMapping of prospective Shale of Indian sedimentary basins.

Collect ion of core samples from drilled wells or through drilling of selective core holes into such shales to generate the following data:

Lithology : Data on shale lithology, mineralogy, clay content, thickness.

Extent: Extension of high gamma ray zones and intercalations of sandstones or siltstones.

Rock property data (porosity, permeability, density).

Rock Eval / Pyrolysis data to identify the type and maturity of organic matter and to detect hydrocarbon potential in sediments.

Thermal Maturity data - vitrinite reflection data, Tmax, S1, S2 peaks.

Gas Content data

Reservoir Characterization

 

KEY CHALLENGES

Following are some of the key points that require deliberation before awarding the

shale gas blocks:

Defining geological conditions

Classification of all unconventional gas resources

Criterion for selection of the developer

Acreages size and terms of lease

De-regulation framework

Fiscal Regime

Availability of water and environmental issues

PRO

• Means more jobs• Less pollution• There is money to be had• May cause lower prices for fuel in the

future • Greater energy security• More money to be had by local and state

governments• Allows for less dependence on foreign

oil

CON

• There are many development issues when it comes to shale gas

• People don’t necessarily want their land dug up

• Wildlife advocates worry about the disturbance of habitats

• n developing a shale gas there are a lot of factors that need to be taken into consideration.

• There is an abundance of paperwork a contractor needs to go through to get the approval to harvest shale gas.

THE SOCIAL SPECTRUM

THANK YOU