Accurate rock typing is essential for reservoir characterization because heterogeneous carbonate reservoirs exhibit complex pore systems that weaken conventional porosity- permeability relationships. This study presents a comprehensive comparative evaluation of conventional and machine learning-based rock typing techniques for the Jeribe-Euphrates carbonate reservoir in the Fauqi Oil Field, southern Iraq. Unlike previous studies that focused on a single classification approach, this work systematically compares Hydraulic Flow Units, Discrete Rock Types, the Winland (R35) method, Lorenz curve analysis, Accumulated Correlation analysis, and machine learning clustering techniques using a unified dataset. The analysis was conducted on 179 core samples with porosity and permeability measurements. Hydraulic Flow Units, Discrete Rock Types, Winland, Lorenz, and Accumulated Correlation methods were applied to classify reservoir rocks, whereas K-means and Expectation-Maximization (EM) algorithms were used to evaluate machine learning-based rock typing. The performance of each method was quantitatively assessed using regression equations, coefficients of determination (R2), variance, standard deviation, and coefficient of variation. The results indicate a weak overall porosity-permeability relationship (R2=0.2675), confirming the pronounced heterogeneity of the studied reservoir. Among all evaluated approaches, the HFU method provided the most consistent and reliable rock classification, identifying four hydraulic flow units with the lowest statistical variability (variance = 0.017423) and the most reliable reservoir-quality characterization. Although the DRT and machine learning approaches achieved high R2 values for some individual classes, their overall classifications exhibited greater variability and lower consistency. Incorporating the Winland pore throat radius (R35) improved clustering performance but did not outperform the Hydraulic Flow Units approach. Overall, the results demonstrate that the Hydraulic Flow Units method is the most suitable approach for defining hydraulic flow units in heterogeneous carbonate reservoirs, providing a reliable framework for reservoir characterization, static geological modeling, and flow unit identification.
Knowing the distribution of the mechanical rock properties and in-situ stresses for the field of interest is essential for many applications concerning reservoir geomechanics, including wellbore instability analysis, hydraulic fracturing, sand production, reservoir compaction, subsidence and water/gas injection throughout the filed life cycle. Determining the rock's mechanical properties is challenging because they cannot be directly measured at the borehole. The recovered carbonate core samples are limited and only provide discrete data for specific depths. This study focuses on creating a detailed 1D geomechanical model of the Mishrif reservoir in the Nasriyah oil field to identify the fault regime type for each unit in the format
... Show MoreThis study has been accomplished by testing three different models to determine rocks type, pore throat radius, and flow units for Mishrif Formation in West Qurna oilfield in Southern Iraq based on Mishrif full diameter cores from 20 wells. The three models that were used in this study were Lucia rocks type classification, Winland plot was utilized to determine the pore throat radius depending on the mercury injection test (r35), and (FZI) concepts to identify flow units which enabled us to recognize the differences between Mishrif units in these three categories. The study of pore characteristics is very significant in reservoir evaluation. It controls the storage mechanism and reservoir fluid prope
The Turonian-Lower Companian succession at Majnoon Oil Field is represented by the Khasib, Tanuma, and Saadi formations. Four major paleoenvironments were recognized within the studied succession, there are: Shallow open marine environment, shoal environment, deep marine environment, and basinal environment. They reflect deposition on a carbonate platform of homoclinal ramp setting. The studied succession represents two second order supersequences (A) and (B). Supersequence (A) includes both the Khasib and Tanuma formations. The Saadi Formation represents cycle (B). These second order cycles can be divided each into two third order cycles, This subdivision may reflect the effect of eustacy being the major controlling factor of cycles dev
... Show MoreFor a huge and important productive reservoir such as Mishrif formation, the key factors for understanding its production performance and to introduce different production scenarios for future planes are its petrophysical properties. These properties may obtain from different sources such as experimental measurements which are a highly costed methods and well logs data. However, well log data cannot be used to find accurate estimation of such properties without an integrated sedimentological analysis. This research focus on petrophysical evaluation of Mishrif formation employing well log data, core analysis, and depositional modeling to elucidate reservoir characteristics and depos
The Carbonate-clastic succession in this study is represented by the Shuaiba and Nahr Umr Formations deposited during the Albian - Aptian Sequence. The present study includes petrography, microfacies analyses, and studying reservoir characterizations for 5 boreholes within West Qurna oil field in the study area. According to the type of study succession (clastic – Carbonate) there are two types of facies analyses:-Carbonate facies analysis, which showed five major microfacies were recognized in the succession of the Shuaiba Formation, bioclastic mudstones to wackstone, Orbitolina wackestone to packstone, Miliolids wackestone, Peloidal wackestone to packstone and mudstone to wackestone identified as an open shelf toward the deep basin.
... Show MoreThere is a growing imperative to extract oil not only through primary and secondary means but also via tertiary recovery methods to meet the escalating global energy demands. Consequently, Enhanced Oil Recovery (EOR) is slated to increase significance in the oil industry in the coming years. The amalgamation of low salinity water (LSW) with chemicals to augment oil recovery has gained substantial traction in recent years owing to its demonstrated effectiveness. In this study, a systematic investigation utilizing contact angle measurements to elucidate the underlying mechanisms was undertaken. The results reveal that the contact angle (CA) demonstrated the effectiveness of the combined fluid in altering the wettability from oil-
... Show MoreThis research was aimed to determine the petrophysical properties (porosity, permeability and fluid saturation) of a reservoir. Petrophysical properties of the Shuiaba Formation at Y field are determined from the interpretation of open hole log data of six wells. Depending on these properties, it is possible to divide the Shuiaba Formation which has thickness of a proximately 180-195m, into three lithological units: A is upper unit (thickness about 8 to 15 m) involving of moderately dolomitized limestones; B is a middle unit (thickness about 52 to 56 m) which is composed of dolomitic limestone, and C is lower unit ( >110 m thick) which consists of shale-rich and dolomitic limestones. The results showed that the average formation water
... Show MoreThe CenomanianÐEarly Turonian reservoirs of the Mishrif Formation of the Mesopotamian Basin hold more than one-third of the proven Iraqi oil reserves. Difficulty in predicting the presence of these mostly rudistic reservoir units is mainly due to the complex paleogeography of the Mishrif depositional basin, which has not been helped by numerous previous studies using differing facies schemes over local areas. Here we present a regional microfacies-based study that incorporates earlier data into a comprehensive facies model. This shows that extensive accumulation of rudist banks usually occurred along an exterior shelf margin of the basin along an axis that runs from Hamrin to Badra a
Using zooplankton as bioindicators, this study evaluates the ecological condition of the Euphrates River in Iraq's Babylon Province. Site 1 (North Hillah, next to the old Babylon ruins), Site 2 (Hillah city center), Site 3 (South Hillah, close to Al-Mahaweel), and Site 4 (near Al-Kifl town) were the four monitoring locations chosen along the river. The highest and lowest averages of the measured physical and chemical factors indicate temperature (25.1°-29.4°), pH (7.2-7.9), electrical conductivity (EC) (940 µS/cm-1241µS/cm), total dissolved solids TDS (591 mg/L-789mg/L), dissolved oxygen (DO) (5.6 mg/ l-7.1 mg/L), biological oxygen demand (BOD5) (2.4mg/L-4.2 mg/L), nitrate (1.3 mg/L–3.2 mg/L), nitrite (0.04 mg/L–0.13 mg/L),
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