The audit of hydrocarbon reserves estimate based on international classification is an established process in a majority of international and Russian companies. The main purpose of the audit is to determine the capitalization of a company, its market value, as well as its collateral value in case of external borrowings and securities offering in stock markets. Zarubezhneft pays special attention to the process of auditing its Russian and international assets, especially with respect to the technical part of the assessment (determination of geological and technical recoverable volumes). Along with the assessment performed by an affiliated international auditor, the Company carries out an internal evaluation to estimate possible results of an independent audit and to form an optimal strategy of asset development.
The process of internal reserves estimate is carried out in accordance with the Procedure adopted by the Company. It consists of three stages: appraisal of geological reserves as of the established date, estimation of technical recoverable volumes and economic assessment. The first stage involves systematization of geological, geophysical, production and design data followed by information analysis to get a comprehensive idea of a reservoir structure and to identify uncertainty (WOC position, petrophysical models, uncertainty in structural plan, etc.). The result of the work at this stage includes geological volumes, calculated according to SEC and SPE/PRMS categories, and graphic maps with selected categories. At the second stage, recoverable reserves by each of the categories are estimated on a well after well basis. The evaluation is based on the actual production dynamics and analogues data. The results of the stage are technical recoverable amounts, final oil recovery factor and anticipated production levels by categories TP, 2P and 3P. Upon obtaining anticipated production profiles, economic appraisal is carried out for each asset based on individual characteristics of the assets (production sharing, inter-Government agreement, etc.) and exploitation targets (very heavy oil, level of reserve depletion, availability of benefits, etc.)
The internal evaluation is based on the use of international standards along with own tools for performance of engineering design. A large amount and variety of input data, as well as specific characteristics of the Group of Companies` assets have caused a necessity to optimize the existing process. The transition to the use of databases, as well as automation of some operations through application of software (tools) has significantly improved the process.
References
1. Guidelines for application of the petroleum resources management system, Publ. of World Petroleum Council, 2011, 197 p.
2. Polozhenie o poryadke organizatsii i sbora iskhodnykh materialov dlya provedeniya nezavisimogo audita zapasov nefti, gaza i kondensata po mezhdunarodnym standartam (Regulations on the procedure for the organization and collection of raw materials for an independent audit of oil, gas and condensate reserves according to international standards), 2014.
