Reservoir Evaluation for Mishrif Formation in R Oil Field, Southern Iraq

miqat alrawi; Basim  Fadhel; Fahad  Mansour

Article Details

Reservoir Evaluation for Mishrif Formation in R Oil Field, Southern Iraq

Authors:

miqat alrawi | Basim Fadhel | Fahad Mansour

Publisher:

Iraqi Geologists Union (Union of Iraqi Geologists)

Journal:

The Iraqi Geological Journal Vol.59 Issue 1F, pp.15-28

Document Type:

Article

Publication Date:

6/2026

Document Language:

English

Document ID (Org No.):

2001837040

pISSN:

2663-8754

Keywords:

Abstract:

 The Mishrif Formation is one of the major carbonate reservoirs at R Oil Field, southern Iraq. The current study sought to evaluate the petrophysical and reservoir properties of this formation. Resistivity, gamma-ray, spontaneous potential, sonic, density, neutron, and caliper logs from seven wells (M1, M2, M3, M4, M5, M6, and M7) have been used. Porosity has been calculated in its different types (primary, total, and secondary), as well as effective porosity. Other petrophysical parameters that were calculated include shale volume, water saturation, oil saturation, both movable and residual. The Mishrif Formation contains two major reservoirs, MA and MB. It is separated by a sealing unit (CR II). MB is the second reservoir unit, further divided into two subunits, MB1 and MB2, based on the main well logs using Techlog 2015.3. Unit MA has low shale volume. The percentage ranges between) 0.04-0.16) gives moderate values for effective porosity(0.09-0.24), and results in favorable hydrocarbon saturation(0.59-.0.83). This indicates good reservoir quality, supported by high movable oil saturation and low residual oil saturation. The second reservoir unit, MB, exhibits good, variable reservoir characteristics. The MB1 subunit has low shale (0.02-0.12), good effective porosity (0.13-0.27), good oil saturation (0.48-0.68), high movable oil, and low residual oil saturation, except for well M4, which recorded 81% residual oil. The MB2 subunit is characterized by excellent effective porosity (0.18-0.26) and low shale content (0.05-0.16). However, the oil saturation is lower (0.44-0.66) than in the previous two units. Reservoir quality is best for MA, followed by MB1. The lower subunit MB2 has a lower-quality reservoir. The best reservoir is in well M1, which is near the crest of the structure. Well M2, located in the southern part of the field, has the worst reservoir among those wells studied.

Article Details

Reservoir Evaluation for Mishrif Formation in R Oil Field, Southern Iraq

Authors:

miqat alrawi | Basim Fadhel | Fahad Mansour

Publisher:

Iraqi Geologists Union (Union of Iraqi Geologists)

Journal:

The Iraqi Geological Journal Vol.59 Issue 1F, pp.15-28

Document Type:

Article

Publication Date:

6/2026

Document Language:

English

Document ID (Org No.):

2001837040

pISSN:

2663-8754

Mishrif Formation

Reservoir Evaluation

Petrophysical Properties

Well Log Interpretation

Carbonate Reservoir

Southern Iraq

Issues

Article Details

Reservoir Evaluation for Mishrif Formation in R Oil Field, Southern Iraq

Authors: miqat alrawi | Basim Fadhel | Fahad Mansour

Publisher: Iraqi Geologists Union (Union of Iraqi Geologists)

Journal: The Iraqi Geological Journal Vol.59 Issue 1F, pp.15-28

Document Type: Article

Publication Date: 6/2026

Document Language: English

Document ID (Org No.): 2001837040

pISSN: 2663-8754

Mishrif Formation

Reservoir Evaluation

Petrophysical Properties

Well Log Interpretation

Carbonate Reservoir

Southern Iraq

Issues

Authors:

miqat alrawi | Basim Fadhel | Fahad Mansour

Publisher:

Iraqi Geologists Union (Union of Iraqi Geologists)

Journal:

The Iraqi Geological Journal Vol.59 Issue 1F, pp.15-28

Document Type:

Article

Publication Date:

6/2026

Document Language:

English

Document ID (Org No.):

2001837040

pISSN:

2663-8754