Shale Oil and Gas

Introduction:

Shale gas & oil is defined as natural gas & oil from shale formations. The shale acts as both the source and the reservoir for these unconventional hydrocarbons. Older shale wells were vertical while more recent wells are primarily horizontal and need artificial stimulation, like hydraulic fracturing, to produce. Only shale formations with certain characteristics will produce gas and oil.

The Government of India has carried out studies through various national and international agencies for the identification of shale oil and gas resources in the country. Based on the data available from conventional oil/gas exploration in the country for the last so many years, the country holds promising reserves of Shale Gas & Oil resources and the following sedimentary basins are considered prospective from Shale oil and gas point of view:

• Cambay Basin
• Gondwana Basin
• KG Basin
• Cauvery Basin
• Indo-Gangetic Basin
• Assam & Assam-Arakan Basin

Various agencies have estimated the shale gas resource potential in selected sedimentary basins/ sub-basins as indicated below:

• Schlumberger: 300 to 2100 TCF of shale gas resource for the country (as available in public domain)
• Energy Information Administration (EIA), USA in 2011: 290 TCF of shale gas in 4 basins (Cambay Onland, Damodar, Krishna Godavari Onland & Cauvery Onland)
• Energy Information Administration (EIA), USA in 2013: 584 TCF of shale gas and 87 billion Barrels of shale oil in 4 basins (Cambay Onland, Damodar, Krishna Godavari Onland & Cauvery Onland)
• ONGC: 187.5 TCF of shale gas in 5 basins (Cambay Onland, Ganga Valley, Assam & Assam-Arakan , Krishna Godavari Onland & Cauvery Onland)
• Central Mine Planning and Design Institute (CMPDI): 45 TCF of shale gas in six sub basins (Jharia¸ Bokaro, North Karanpura, South Karanpura, Raniganj & Sohagpur)
• USGS under MoU between DoS & MoPNG in Jan’11 estimated Technical Recoverable Shale Gas of 6.1 TCF for three basins, namely, Cambay, KG & Cauvery. Further, USGS in April 2014 estimated Technical Recoverable volume of 62 million barrels of shale oil for Cambay Basin and more than 3.7 TCF of technical recoverable gas for Tight Sandstone reservoirs for Cambay & KG basins. Further, USGS has indicated that these basins have also potential for shale oil.

Policy Initiatives by Govt. of India:

Ministry of Petroleum & Natural Gas, Govt. of India vide policy dated 14^th October 2013 granted permission for Shale gas and oil exploration and exploitation initially only by NOCs (ONGC & OIL) in on-land nomination blocks i.e. blocks awarded to the NOCs on nomination basis before the advent of Pre-NELP and NELP PSCs. The policy was announced with exclusive purpose of promoting Shale Gas & Oil operations in the existing onland PEL/PML areas under Nomination acreages in the overall interest of energy security in the country.

As per the policy, the NOCs have been permitted three Assessment Phases for exploration (Phase I, II & III) of 3 years. Each Phase will culminate in a development and production phase depending on the results of the Assessment Phase.

As per the Policy, the NOCs are obligated to carry out committed work program in respect of following for each identified block:

• Baseline EIA study including sourcing of water and its subsequent disposal.
• G&G Studies
• Drilling of pilot/test wells
• Coring, hydro-fracturing etc.
• Geochemical studies
• Geo-mechanical/Geo-hazard/Geo-technical studies
• Resource Assessment for Shale Gas and Oil

Minimum no. of PEL/PML areas to be taken up by the NOCs during each Assessment Phase is specified in the Policy and is as follows:

However, the company shall have the liberty to take-up more no. of PEL/PML areas for Shale Gas exploration & exploitation. For the purpose of phasing, each PEL/PML area is treated as a BLOCK.

Current Status on Exploration of Shale Gas & Oil:

As per the policy guidelines, ONGC have identified and initiated exploration activities for Shale Gas & Oil in 50 nomination blocks respectively under Phase-I. The details of identified blocks by ONGC are as under:

OIL:

As per the policy guidelines, OIL have identified and initiated exploration activities for Shale Gas & Oil in 6 nomination blocks respectively under Phase-I. The details of identified blocks by OIL are as follows:

As per the information furnished by OIL, G&G activities in these identified blocks is in progress to identify prospective locations for drilling of Shale Gas & Oil wells.