A Review of Historical Studies for Water Saturation Determination Techniques

Carbonate reservoirs are an essential source of hydrocarbons worldwide, and their petrophysical properties play a crucial role in hydrocarbon production. Carbonate reservoirs' most critical petrophysical properties are porosity, permeability, and water saturation. A tight reservoir refers to a reservoir with low porosity and permeability, which means it is difficult for fluids to move from one side to another. This study's primary goal is to evaluate reservoir properties and lithological identification of the SADI Formation in the Halfaya oil field. It is considered one of Iraq's most significant oilfields, 35 km south of Amarah. The Sadi formation consists of four units: A, B1, B2, and B3. Sadi A was excluded as it was not filled with hydrocarbons. The structural and petrophysical models were built based on data gathered from five oil wells. The data from the available well logs, including RHOB, NPHI, SONIC, Gamma-ray, Caliper, and resistivity logs, was used to calculate the petrophysical properties. These logs were analyzed and corrected for environmental factors using IP V3.5 software. where the average formation water resistivity (Rw = 0.04), average mud filtrate resistivity (Rmf = 0.06), and Archie's parameters (m = 2, n = 1.9, and a = 1) were determined. The well-log data values calculated the porosity, permeability, water saturation, and net-to-gross thickness ratio (N/G).

Section:  Flow Zone Indictor (Fzi) Methodsmentioning

confidence: 99%

Petrophysical Analysis Based on Well Logging Data for Tight Carbonate Reservoir: The SADI Formation Case in Halfaya Oil Field

Jassam,

AL-Fatlawi,

Canbaz

2023

“…There are a lot of techniques to determine water saturation [22], in this study water saturation was determined using Archie's equation. Therefore, formation resistivity, water resistivity, and Archie's parameters have been determined using the Pickett plot.…”

Section: Water Saturationmentioning

confidence: 99%

Evaluation of the Mishrif Formation Using an Advanced Method of Interpretation

Al-Heeti

Al-Fatlawi

Hossain

2023

The Mishrif Formation is one of the most important geological formations in Iraq consisting of limestone, marl, and shale layers since it is one of the main oil producing reservoirs in the country, which contain a significant portion of Iraq's oil reserves. The formation has been extensively explored and developed by the Iraqi government and international oil companies, with many oil fields being developed within it. The accurate evaluation of the Mishrif formation is key to the successful exploitation of this field. However, its geological complexity poses significant challenges for oil production, requiring advanced techniques to accurately evaluate its petrophysical properties. This study used advanced well-logging analysis techniques, including mineralogical inversion with the Quanti-Elan model employed in Schlumberger's Techlog software to evaluate this formation. The lithology, clay volume, porosity, permeability, and hydrocarbon saturation data were obtained from the open hole logging of three wells in a southern Iraqi oil field. The environmental correction was applied for open-hole logging tools, and the primary mineral of the formation was determined using porosity log cross-plotting. Pickett plot technique was utilized to determine water resistivity and Archie's parameters, and the reconstruction log was generated based on volumetric and response parameters for each component. Based on thorough analysis, the clay volume of the Mishrif formation is estimated to be about 10%, which is a common value for this rock type. The porosity was computed based on the total fluid volume, ranging from 11% to 14%, and water saturation was determined using Archie's equation. The final results of the volume of each component for rock and fluid are presented using computer programming interpretation. The results of this study provide valuable insights into the petrophysical properties of the Mishrif formation and are expected to inform for better interpretation and evaluation of petrophysical properties of similar formations, which is essential for optimum field development planning as well as minimising the uncertainties.

“…Identifying the quantity of clay in shale sand is the most crucial step [24]. It is feasible to compute adequate water saturation and effective porosity more precisely if reservoir clay content is known [25]. Reservoir rocks should be capable of transmitting hydrocarbon fluids through their pores [26].…”

Section: -Introductionmentioning

confidence: 99%

“…When appraising a formation, its petrophysical qualities are taken into account. It must be determined precisely [25]. A fluid's saturation level can be expressed as a fraction or a percentage of the total pore volume it occupies (oil, gas, or water).…”

Section: -Introductionmentioning

confidence: 99%

Estimation of the Petrophysical Properties of the Lower Cretaceous Yamama (YC) Formation in Siba Field

Hadi,

Al-Fatlawi,

Kadkhodaie

2023

In southern Iraq, the Yamama Formation has been a primary carbonate resource since the Lower Cretaceous era. This study covers Siba Field, which is located in southeastern Iraq. This paper will be devoted to a YC unit of study. The most crucial step in reservoir management is petrophysical characterization. The primary goal of this research is to assess the reservoir features and lithology of the Yamama (YC) Formation in the Siba region. Accessible excellent logs include sonic, density, neutron, gamma-ray, SP, and resistivity readings. The Interactive Petrophysics (IP4.4) program examined and estimated petrophysical features such as clay volume, porosity, and water saturation. The optimum approach was the neutron density and clay volume calculation using the Gamma Ray Method (VclGR), it was 0.246 in SB-6 since they are not impacted by anything. The Archie method was chosen due to its suitability for limestone. The lithology and mineralogy of the formations were determined using M-N cross plots; the diagram revealed that the Formation was composed of limestone. The Archie parameter was determined using the Pickett plot and formation water resistivity from the Pickett plot and SP log where the results were similar in all wells (RW=0.016, m=2.08, n=2.3, a=1.1). In addition, the higher section of the formation has good reservoir qualities such as density is (2.368g/cc), porosity is (PHIE=0.117) in SB-6.