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.
Highlights
Nahr Umr formation is one of the promising reservoir in southern of Iraq
Nahr Umr formation characterized by complex lithology, high scatter dense in permeability and porosity and high water salinity
Standard set of logs such as gamma ray, static spontaneous, resistivity, density, neutron and sonic have been almost acquired in every well across Nahr Umr formation
Summary
Nahr Umr formation is one of the promising reservoir in southern of Iraq. The formation characteristic is almost the same in all southern Iraqi oil fields. Well tests, core data and core analysis consider the most common petrophysical tools used to evaluate and assess the reservoir. Standard set of logs such as gamma ray, static spontaneous, resistivity, density, neutron and sonic have been almost acquired in every well across Nahr Umr formation. Nahr Umr formation was practical approach for generating a worthy trust divided into 4-layers, (A, B, C and D) (Geological integrated petrophysical model for a heterogeneous Study for Subba Oil Field, 2001), these layers consist shaly sand reservoirs depending on available old data. Mainly of sandstone, shale and low ratio of siltstone (Geological and Evaluation Study for Subba Oil Field, The description of nahr umr formation in the subba 1979; Geological Study for Subba Oil Field, 2001).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Research Journal of Applied Sciences, Engineering and Technology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.