Perm Journal of Petroleum and Mining Engineering (Sep 2015)

Determining openness and compressibility of natural fractures of carbonate reserves in the Logovskoye deposit

  • Dmitrii A. Martiushev,
  • Aleksandr V. Lekomtsev,
  • Andrei G. Kotousov

DOI
https://doi.org/10.15593/2224-9923/2015.16.7
Journal volume & issue
Vol. 14, no. 16
pp. 61 – 69

Abstract

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The large amounts of hydrocarbons and produced oil in Perm krai are found in carbonate reservoirs. Accurate determination of reservoir properties is currently one of the topical issues. Laboratory studies of core samples do not always allow to evaluate parameters of fractured environment because of the eventual core destruction (along the fractures) at the surface and tiny dimensions of the samples investigated. A method to determine parameters of natural fractures involving tracer injection into the injection wells in the Logovskoye deposit, Perm krai (Tournaisian-Famennian deposit) is presented. The data obtained by tracer studies are compared to those got by other methods of evaluating openness of natural fractures, such as a Warren-Root formula applied to process pressure build up curves in reservoirs with natural fracturing, and the relation discovered by V.D. Viktorin for carbonate reservoirs of Perm krai. An error of the results received by different methods does not exceed 5 %, which means fidelity and overall accuracy of the techniques applied and their feasibility for investigation of fracturing in carbonate reservoirs. It is established that pressure conductivity in carbonate reservoirs varies from the highest value corresponding to pressure conductivity in fractured-porous formation to the lowest value corresponding to pressure conductivity in the matrix pores. This allows us to conclude that a reservoir features natural fracturing. One of the most serious issues in 3D-simulation, especially of carbonate reserves, is accurate determination of permeability, openness and directional attitude of natural fractures. The studies with tracers coupled with hydrodynamic research (pressure interference test) in the process of carbonate reserves development permit to improve the quality of input data and fidelity of prediction calculations.

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