The Mishrif Formation is one of the most important formation in oil fields, which is located in southern part of Iraq, and it is of Upper Cretaceous age. Tuba field is located nearly 40 km SW – Basrah city. It is bounded from east by Zubair oil field (5 km distance) and from west by Rumaila (2 km distance). The Tuba oil field is situated between Zubair oil field in the east and Rumaila in the west, and is separated by two depressions.
The rock (core and chips) samples have been collected systematically from cores of Mishrif Formation that are available from stores of southern oil company to prepare thin sections and slides—these slides have been examined by using microscope. These samples have been taken from all parts of the reservoir units of Mishrif, namely, mA, mB1, mB2 units. Twenty-four samples have been applied to the petrophysical tests to measure the porosity and permeability. The water and oil saturations have been identified by consulting the log documents for studied wells (7 wells). Besides, four hundred ten rockslides have been made for identifying the facies and diagenices processes.
Four main facies have been diagnosed at Mishrif Formation (Grainstone, packstone, wackstone and mudstone) which are spread all over the reservoir units. Moreover, the diagentic processes have been identified by using microscope to check the rockslides, which have greatly framed the petrophysical characteristics for Mishrif Formation. These processes include dissolution, all categories of porosity, compaction, cementation, new morphisim and dolomitization.
The results of the reservoir geological model show that Tuba field is an anticline fold which its extension is in (north – northwest), (south- southeast) direction. The results have proved that facies model distribution completely match the facies description in the study. This model contains Grainstone, Packstone, Wackstone and Mudstone.
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Increasing hydrocarbon recovery from tight reservoirs is an essential goal of oil industry in the recent years. Building real dynamic simulation models and selecting and designing suitable development strategies for such reservoirs need basically to construct accurate structural static model construction. The uncertainties in building 3-D reservoir models are a real challenge for such micro to nano pore scale structure. Based on data from 24 wells distributed throughout the Sadi tight formation. An application of building a 3-D static model for a tight limestone oil reservoir in Iraq is presented in this study. The most common uncertainties confronted while building the model were illustrated. Such as accurate estimations of cut-off perm
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This study involves microfacies analysis of the Kometan Formation from northeastern Iraq supported by detailed petrographic investigation for the main components and diagenetic processes using a petrographic microscope, scanning electron microscope (SEM), and X-Ray diffraction (XRD). The techniques have revealed that the formation includes two microfacies; lime wackestone and lime packstone microfacies which in turn are subdivided into seven sub-microfacies, that were deposited in the quiet and deep marine environment. Planktonic foraminifera (keeled and globular chamber types) are dominant, along with oligostegina in addition to subordinate benthonic foraminifera and fine-grained bioclasts. Calcite forms the main mineralogical compositi
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The sediments of the Hartha Formation were deposited during the Upper Campanian- Maastrichtian cycle. Due to the importance of this sequence in terms of stratification and economics in the oil industry, it has been focused on in this study. The present study includes three oil fields in central of Iraq within the Mesopotaminan Zone, East Baghdad, Balad and Kifl oil fields. This study was accomplished by describing 190 thin sections and interpreting the response of the available well logging data. Seven major microfacies were diagnosed in the Hartha succession at studied oil fields, they are; Orbitoidal wackestone - packstone, Orbitoidal and miliolids wackestone, Rotaliidae and Siderolites with echinodermata wackestone - packstone,
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The main objective of this study is to develop a rate of penetration (ROP) model for Khasib formation in Ahdab oil field and determine the drilling parameters controlling the prediction of ROP values by using artificial neural network (ANN).
An Interactive Petrophysical software was used to convert the raw dataset of transit time (LAS Readings) from parts of meter-to-meter reading with depth. The IBM SPSS statistics software version 22 was used to create an interconnection between the drilling variables and the rate of penetration, detection of outliers of input parameters, and regression modeling. While a JMP Version 11 software from SAS Institute Inc. was used for artificial neural modeling.
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This paper presents a comparative study between different oil production enhancement scenarios in the Saadi tight oil reservoir located in the Halfaya Iraqi oil field. The reservoir exhibits poor petrophysical characteristics, including medium pore size, low permeability (reaching zero in some areas), and high porosity of up to 25%. Previous stimulation techniques such as acid fracturing and matrix acidizing have yielded low oil production in this reservoir. Therefore, the feasibility of hydraulic fracturing stimulation and/or horizontal well drilling scenarios was assessed to increase the production rate. While horizontal drilling and hydraulic fracturing can improve well performance, they come with high costs, often accounting for up t
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A 3D Geological model was generated using an advanced geostatistical method for the Cretaceous reservoir in the Bai Hassan oil field. In this study, a 3D geological model was built based on data from four wells for the petrophysical property distribution of permeability, porosity, water saturation, and NTG by using Petrel 2021 software. The geological model was divided into a structural model and a property model. The geological structures of the cretaceous reservoir in the Bai Hassan oil field represent elongated anticline folds with two faults, which had been clarified in the 3D Structural model. Thirteen formations represent the Cretaceous reservoir which includes (Shiranish, Mashurah, U.kometan, Kometan Shale, L. Kometan, Gulnen
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Many oil and gas processes, including oil recovery, oil transportation, and petroleum processing, are negatively impacted by the precipitation and deposition of asphaltene. Screening methods for determining the stability of asphaltenes in crude oil have been developed due to the high cost of remediating asphaltene deposition in crude oil production and processing. The colloidal instability index, the Asphaltene-resin ratio, the De Boer plot, and the modified colloidal instability index were used to predict the stability of asphaltene in crude oil in this study. The screening approaches were investigated in detail, as done for the experimental results obtained from them. The factors regulating the asphaltene precipitation are different fr
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Seismic facies analysis constrained with well log information have been used to predict lithofacies distribution across the Okam Field of Niger Delta. Density and gamma ray logs were cross-plotted and the seismic section was subdivided vertically into different seismic facies. The delineated lithologies, from well logs were correlated with seismic facies signatures using lines of intersection across the wells. Gamma ray and resistivity logs were used to identify the interfaces between the lithofacies and correlated across the field. Structural interpretation was carried out. Time slices were generated and examined at different intervals within the identified reservoirs. Stratigraphic related attribute and envelope were extracted on these
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