India's Hydrocarbon Outlook – 2022-2023

166 DGH: 3 DECADES OF UNLOCKING INDIA'S HYDROCARBON POTENTIAL 7.2 Shale Gas/Oil Shale gas/oil is a form of natural gas/oil that remain unexpelled, unmigrated, and entrapped within the pore space and fractures of a source rock (commonly, shale). They are categorized as an unconventional resource due to their nature of occurrence and method of extraction. In general, shales have insufficient permeability (usually in Nano Darcy i.e. 10-9 D) for fluid flow to a well bore. The shale gas/oil is produced commercially when sufficient fracture conductivity is induced by hydraulic fracturing. In contrast to conventional play exploration where the risk profile is governed by the presence and effectiveness of source, reservoir, trap, timing, and migration of hydrocarbon, shale gas/oil exploration has a much different and usually more predictable risk profile. The gas shale itself contains all of the elements of petroleum risk as mentioned. The producibility of shale gas is not just limited to a single prospect but to a larger geographic region. Thus, in a proven shale play, the challenge is to develop the proper drilling and completion techniques to optimize the gas production rate versus capital employed and operating costs. In India, a preliminary resource assessment of Shale gas/oil was carried out by three different organizations. In 2011, the United States Geological Survey (USGS) estimated the technically recoverable Shale gas/oil as 6.1 TCF for 3 basins: Cambay, Krishna-Godavari (KG), and Cauvery. Again in 2014, it estimated a technically recoverable volume of 62 million barrels of shale oil in Cambay Basin alone. In 2013, the National Oil Company, ONGC estimated Shale Gas resources of 187.5 TCF from 5 sedimentary basins: Cambay, KG, Cauvery, Ganga, and Assam. CMPDI in July 2013 had estimated around 45.8 TCF in the Gondwana basin. In order to understand the prospectivity and untap the Shale Gas and Oil resource potential in India, GoI announced a Shale gas and Oil exploration policy on 14th October 2013 for the National Oil Companies (NOCs), ONGC, and OIL. The companies were required to carry out exploration in their PML and ML areas in three phases. 7.2.1 Shale Gas/Oil Policy Reforms In addition to the policies notified in 2016 (HELP) and 2018 (Unconventional), in Oct 2018, a policy framework to promote and incentivize Enhanced Recovery Methods for Oil and Gas was notified by the Ministry of Petroleum and Natural Gas, Government of India. Under this policy, fiscal incentives are provided from the first day of the entire production from future discoveries of unconventional hydrocarbons (Shale Gas/Oil and Gas Hydrate). Many CBM operators have shown interest for exploiting the Shale Gas Resources in their region. 7.2.2 Summary of Shale Gas/Oil Activities in India Under the Shale Gas Policy - 2013, 50 blocks in 4 basins; Assam, Krishna Godavari, Cauvery & Cambay were identified by ONGC, and 6 blocks in 2 basins; Jaisalmer and Assam were identified by OIL in the Phase-I of exploration which ended in April-2017. Basin Phase-I Blocks Blocks Taken up for Drilling Actual Wells Drilled Cambay 28 16 17 KG 10 6 8 Cauvery 9 1 3 Assam 3 2 2 Total 50 25 30 Table 7.5: Basin-wise work carried out by ONGC in its nomination areas: