Research Article | OPEN ACCESS
Integrated Petrophysical Evaluation of a Heterogeneous Shaly-sand Reservoir: A Case Study in Nahr Umr Formation-subba Giant Oil Field, Iraq
1Ahmed Khalil Jaber and 2Muhannad Talib Shuker
1SPE, Universiti Teknologi PETRONAS, Ministry of Oil, Iraq
2SPE, Universiti Teknologi PETRONAS, Malaysia
Research Journal of Applied Sciences, Engineering and Technology 2014 24:2388-2402
Received: June 14, 2014 | Accepted: July 19, 2014 | Published: December 25, 2014
Abstract
This study presents an integrated petrophysical evaluation for Nahr Umr reservoir by highlighting a practical trustworthy approach petrophysical model for Nahr Umr reservoir in Subba oil field depending on available data. The available data include core analysis conducted on seven core samples taken from seven wells in Subba oil field and well set logs which include gamma ray, static spontaneous, neutron, sonic, density and resistivity logs. Subba oil field is a giant oil field located in southern part of Iraq about 110 km Northwest Basra. Nahr Umr formation in Subba oil field is a heterogeneous clastic reservoir. It was considered one of the most important producing clastic reservoir in southern Iraqi oil fields. The conventional petrophysical models, by using neutron-density cross-plot for lithology and porosity and Archie's equation for water saturation, can be adequate for evaluating clean sands. Usually the shaly sand formations are adhere to bad hole in shale section. Facies identification was achieved depending on core analysis data, core description data and wire line log measurements. The calculations of permeability was based on rock types identification and using available core data measurements. The generated permeability models can be used to calculate permeability for uncored intervals in all wells corresponding to each facies. Porosity was calculated using Neutron-density porosity model and Sonic model for bad hole section. Saturation model was built by utilizing the Indonesia Equation model, this model has proved its efficiency to be applied successfully for clastic Iraqi reservoirs. The petrophysical parameters were determined on a well-by-well basis. The formation resistivity factors (a, m) and water saturation exponent (n) have been derived from Pickett plot and formation water salinity. Reservoir quality calculations or net pay values are based on cut-offs values for porosity, saturation and shale volume.
Keywords:
Heterogeneous shaly-sand reservoir, integrated petrophysical evaluation, nahr umr formation/subba oil field, permeability, petrophysical parameters calculations,
References
-
Al-Ajmi, F.A. and S.A. Holditch, 2000. Permeability estimation using hydraulic flow units in a central Arabia reservoir. Proceeding of the SPE Annual Technical Conference and Exhibition. SPE 63254, Dallas, Texas, October 1-4.
CrossRef
-
Ministry of Oil, 1980. All the Core Measurements Reports for Nahr Umr Formation-Subba Oil Field, 1976-1980. Ministry of Oil, Baghdad, Iraq.
-
Amaefule, J.O., M. Altunbay, D. Tiab, D. Kersey and D. Keelan, 1993. Enhanced reservoir description: Using core and log data to identify hydraulic (Flow) units and predict permeability in uncored intervals/wells. Proceeding of the SPE Annual Technical Conference and Exhibition. SPE 26436, Houston, Texas, October 3-6.
-
Andre, P. and L. Jacques, 1971. Evaluation of Water Saturation in Shaly Formations. Proceeding of the SPWLA 12th Annual Logging Symposium, Dallas, Texas, May 2-5.
-
Geological and Evaluation Study for Subba Oil Field, 1979. Exploration Oil Company-Baghdad, Iraq.
-
Geological Study for Subba Oil Field, 2001. Ministry of Oil-reservoir and Field Development Directorate. Baghdad, Iraq.
-
Gunter, G.W., J.M. Finneran, D.J. Hartmann and J.D. Miller, 1997. Early determination of reservoir flow unit using an integrated petrophysical method. Proceeding of the SPE Annual Technical Conference and Exhibition. SPE 38679, San Antonio, Texas, October 5-8.
CrossRef
-
Guo, G., M.A. Diaz, F. Paz, J. Smalley and E.A. Waninger, 2005. Rock typing as an effective tool for permeability and water-saturation modeling: A case study in a Clastic reservoir in the Orienta basin. Proceeding of the SPE Annual Technical Conference and Exhibition. SPE 97033, Dallas, Texas, October 9-12.
CrossRef
-
Saleh, B.A. and H.A. Hilal, 2004. Petrophysical models and techniques for shaly-sand formation evaluation. Proceeding the 11th Annual International Petroleum Exhibition and Conference. SPE 88686, Abu Dhabi, UAE, October 10-13.
-
Well Logs for Nahr Umr Formation-Subba Oil Field, 1973-1980. South Oil Company, Basra, Iraq.
Competing interests
The authors have no competing interests.
Open Access Policy
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Copyright
The authors have no competing interests.
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ISSN (Online): 2040-7467
ISSN (Print): 2040-7459 |
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