مدل بهره برداری بهینه از منابع نفتی در هند

In this paper, the exploitation of petroleum resources in India is analyzed by developing a dynamic optimization modeling framework—PETEX. This model combines the practical aspects in determining optimal rates of extraction of oil and gas from a reservoir with a hybrid approach to estimating the discovery rate of petroleum resources in the future, additionally incorporating a stochastic specification to capture the uncertainty associated with discovery. The model acts as an aid to joint production–investment decision making for the entire supply process from drilling through production and in determining the import requirement to meet the country’s oil demand. The model results and sensitivity analysis suggest an acute requirement of sustained infusion of investment into the various upstream activities at a rate much higher than the current levels in order to bridge the demand—supply gap for crude oil. With the opening up of the Indian economy, it is hoped that the participation of the private sector in upstream activities would increase thereby increasing the investments available for upstream activity.

India has about 0.5% of the world’s proven oil reserves (BP, 2003). The prognosticated geological resources of hydrocarbons in the country are estimated at 21.31 billion tonnes, of which 61% are offshore and 39% onshore. However, of this, the established geological reserves are only 5.32 billion tonnes. It is believed that half the prognosticated resource represents natural gas, of which 12% has been established to date (Government of India, 1997). As of the beginning of 2001, the balance of recoverable reserves is placed at 733.7 million tons of crude and 749.65 billion cubic meters of natural gas (Government of India, 2002). India imports approximately 74% of its crude oil requirements (around 115 million tons per year), the approximate total installed capacity of domestic refineries. The value of crude oil imports during the year 2001–02 was 12.6 billion US dollars, constituting about 40% of the total export earnings of the country. The production of crude oil in the country has stagnated at around 30 million tons per year. The gap between domestic supply and demand for crude oil in the country has been steadily increasing over the years with additional refining capacity rising to meet increasing domestic petroleum products demand. The issue of managing this growing demand for oil is a critical aspect of India’s future energy policy. A large proportion of oil supply activities, including exploration, extraction and transportation of crude oil and gas in India is currently being handled by government-controlled organizations. In the now liberalized scenario, investment from the private sector is being encouraged. The upstream activities (exploration and extraction) are in dire need of investments and these investments, being scarce resources, need to be spread among various potentially productive basins. The hydrocarbon reserves in India are distributed in 26 sedimentary basins of which 13 are considered more prospective. These basins are classified into four categories, of which Category I basins are those currently producing and the Category II, III and IV basins are those with declining levels of prospectivity. The known recoverable reserves of oil and gas are concentrated in two onshore basins—Cambay (ON1) and Assam (ON2), and one offshore basin—Bombay offshore (OF1). These three basins are classified as Category I basins. There are three other onshore basins—Assam-Arakan (ON3), Krishna-Godavari onshore (ON4), Cauvery onshore (ON5), and four other offshore basins—Gulf of Cambay (OF2), Kutch-Saurashtra (OF3), Krishna-Godavari offshore (OF4) and Cauvery offshore (OF5), at various stages of development. These constitute the Category II basins1. In this study, it is assumed that all the basins in India with hydrocarbon potential are aggregated under the ten basins in consideration.2 Petroleumand gas are scarce resources and of strategic importance. The decision making process of the upstream aspects of supply has to simultaneously account for the exploration and extraction activities in an integrated framework to bring in additional flexibility in terms of weighing their relative importance and merit.

The model suggests a sustained infusion of investment towards exploratory drilling in the Category I basins, namely the Bombay offshore, Cambay onshore and Upper Assam basins, which show good discovery potential across the model years. • The onshore Category II basins of Krishna-Godavari and Cauvery are found to have the best discovery potential among all basins and the model suggests augmented investment in these basins for exploratory drilling. Among offshore Category II basins, the Gulf of Cambay basin is found to have the best discovery potential. • The Category II basins that show good discovery potential may progressively contribute a sizeable proportion of the overall production and thus it is imperative that more investments are dedicated to these basins. • However, in spite of some of the Category II basins showing good discovery potential and hence good potential for production, the model suggests that the Category I basins will continue to be the main source of crude oil during the model time period with the Bombay offshore basin alone accounting for approximately two-thirds of the production. • If the investments into the various upstream activities were not to increase much beyond the current levels, the model suggests that the reserve accretion and hence the production would be unable to bridge the demand–supply gap. Under such circumstances, the proportion of import of crude oil to meet the domestic demand would continue to increase. • For natural gas, the model suggests that the discovery potential for onshore basins being higher than that for offshore basins, it would be optimal to direct more future investments towards onshore basins to establish and develop the gas resources.