The Role of Basin and Petroleum Systems Modeling in the 2015-2017 India National Resource Assessment Project

Abstract

In 2015, the Government of India assigned a project to ONGC, the Indian national oil and gas company, to assess the Yet-to-Find (YTF) conventional hydrocarbon resources in all 26 sedimentary basins in the country. The work was to be undertaken by the ONGC asset teams responsible for the basins, and more than 50 G&G staff at 7 locations were assigned full-time for more than 2 years to the project. The sedimentary basins of India are subdivided into four categories: I Proven Commercial (7 basins), II Identified Prospectivity (3 basins), III Prospective (6 basins) and IV Potentially Prospective (10 basins). Basins are both onshore and offshore and the age of the sedimentary fill ranges from Proterozoic to late Tertiary. Data availability ranges from thousands of wells in the producing basins to no subsurface data in some frontier basins. This indicates a key challenge of the project, the need to standardize the methodology to enable a more objective assessment of the country’s resource potential. Each basin was rigorously studied following industry best practices and a standardized process: 1) complete review of all available G&G data and analogues, 2) assembly of a static exploration data model of each basin to support data QC, if possible in 3D, 3) petroleum systems modeling to enable risking of the petroleum systems elements and processes in the basin, 4) mapping of chance of success and Assessment Units, and 5) probabilistic assessment of YTF resources to deliver a national database including risking and ranking of more than 180 plays and 800 Assessment Units in all basins, as well as the resulting aggregates for the basins and the entire country. Basin and Petroleum Systems Modeling played a fundamental role and examples of its strategic importance include a) controlling the integration of all G&G data in static and dynamic geological models, b) screening with petroleum systems criteria as an initial reality check in all basins, c) implementation of a standard risk model based on the key petroleum systems elements as a bridge between deterministic and probabilistic modeling, and d) provision of a basin and play scale framework for future exploration efforts. In the talk we present examples of the application challenges, methodologies, pitfalls and result types related to the Petroleum Systems Modeling. Analysing 26 basins in a single project has provided a unique opportunity to learn from the experience of implementing a rigorous and standardized approach.

AAPG Datapages/Search and Discovery Article #90332 © 2018 AAPG International Conference and Exhibition, Cape Town, South Africa, November 4-11, 2018