Volumetric control for hydrocarbon resources estimations based on geochemical laboratory measurements

UDK: УДК 553.98.048

Key words: volumetric method, geochemistry, Rock-Eval, hard-to-recover reserves, petroleum reserves and resources estimation, coalbed methane, Bazhenov formation

Authors: I.S. Gutman, G.N. Potemkin, I.Yu. Balaban, A.V. Postnikov, O.V. Postnikova (Gubkin Rusian State University of Oil and Gas, RF, Moscow), M.I. Saakian (State Reserves Commission under Ministry of Natural Resources of the RF, RF, Moscow), V.V. Zhukov, A.D. Alekseev, I.A. Karpov (Gazprom Neft JSC, RF, Saint-Petersburg), M.Yu. Spasennykh, E.V. Kozlova (Skolkovo Institute of Science and Technology, RF, Moscow).

The article concerns the problem of quantitative evaluation of hard-to-recover hydrocarbons, such as coalbed methane and Bazhenov shale oil. The application of geochemical parameters obtained from small rock samples requires analytical control. The procedure for equivalent volumetric parameters assessment is shown, that allows to control the amount of resources and reserves, obtained on the basis of geochemical laboratory measurements. For the West Siberian field specific resources were calculated based on Rock-Eval parameters, and equivalent thickness was obtained in order to compare with developed deposit. There are three types of hydrocarbons in analysis: movable hydrocarbons of carbonate and siliceous rocks with complex porous media; liquid “trapped” hydrocarbons; and temperature-generated ones from kerogen. Direct usage of core pyrolytic parameters for Bazhenov resources leads to overestimation. Bazhenov resources according to different estimates vary from 600 mn. tons to 175 bn. tons. Using equivalent thickness approach for Bazhenov formation it is possible to carry out verification of resources obtained from pyrolytic methods. Pyrolysis could be applied to resources estimation, given standardized core sample preparation and examination, as well as valid technique for conversion of pyrolytic parameters into variables used to estimate reserves.
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