Title: Investigation of cementation exponent (m) in heterogeneous carbonate reservoirs via integration of thin section analysis and well logging

Authors: Siyamak Moradi; Abdorrahman Moghani Rahimi; Ghasem Zargar; Mehdi Kakavandi

Addresses: Exploration Engineering Department, College of Petroleum Engineering, Abadan, Iran ' College of Petroleum Engineering, Petroleum University of Technology, Abadan, Iran ' Reservoir Engineering Department, Petroleum University of Technology, Abadan-Ahvaz, Iran ' National Iranian South Oil Company (NISOC), Expert of Petro Physic Department, Iran

Abstract: Cementation exponent (m) is one of the most important parameters in calculation of water saturation from Archie's equation especially in heterogeneous carbonate reservoirs. The complexity and wide variations in the nature of pore systems in these reservoirs causes the cementation exponent to be variable with depth and ignoring this variation will lead to significant errors in calculation of water saturation and hydrocarbon in place. In this paper, cementation exponent is determined by using an improved triple porosity model developed by Aguilera (2004). Pore systems are characterised in a 150 metre interval by preparing 64 thin sections from the core plugs for petrographic analysis. Pore types are classified via microscopic analysis of sections followed by an image processing approach. Calculated m-values are used to predict water saturation and the results are compared to core data. It is observed that Archies equation successfully predicts water saturation of this heterogeneous medium if appropriate m-values from improved triple porosity model are used. [Received: June 29, 2013; Accepted: January 28, 2014]

Keywords: cementation exponent; carbonate reservoirs; triple porosity; thin sections; pore types; oilfields; oil industry; Iran; gas technology; well logging; water saturation; hydrocarbons; modelling; core plugs; petrographic analysis; microscopic analysis; image processing.

DOI: 10.1504/IJOGCT.2015.069679

International Journal of Oil, Gas and Coal Technology, 2015 Vol.9 No.4, pp.379 - 393

Received: 12 Jul 2013
Accepted: 28 Jan 2014

Published online: 29 May 2015 *

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