The characterizations of reservoir require reliable knowledge of certain fundamental reservoir properties. Log measurements can define or at least infer these properties: resistivity, porosity, shale volume, lithology, and water, oil, or gas saturation and permeability. The current study represents evaluation of petrophysical properties in well LU-12 for Zubair Formation in Luhais Oil Field, southern Iraq. The petrophysical evaluation was based on geophysical well logs data to delineate the reservoir characteristics of Zubair Formation. The available geophysical well logs such as (sonic, density, neutron, gamma ray, SP, and resistivity logs) are digitized using the Didger software. The environmental corrections and petrophysical parameters such as porosity, water saturation, hydrocarbon saturation, bulk water volume, etc. were computed and interpreted using Interactive Petrophysics program. Lithological, mineralogical and matrix identification studies were estimated using porosity combination cross plots. Petrophysical properties were determined and plotted as computer processing interpretation (CPI) using Interactive Petrophysics program. Zubair Formation in Luhais oil field is divided into three units according to petrophysical properties: Upper Zubair, Middle Zubair, and Lower Zubair. Middle Zubair is characterized by good porosity but high water saturation. Interpretation of well logs of Zubair Formation founds that Zubair Formation production in well LU-12 is noncommercial but present weak oil shows in some ranges of the formation especially in upper and lower Zubair units but middle Zubair is characterized by free oil shows .Lithological study of Zubair Formation appears that it consists mainly of interbedded sandstone, shale, and shale sandstone whereas mineralogy of Zubair Formation consists mainly of quartz sandstone and Some calcite.
Flow unit and reservoir rock type identification in carbonates are difficult due to the intricacy of pore networks caused by facies changes and diagenetic processes. On the other hand, these classifications of rock type are necessary for understanding a reservoir and predicting its production performance in the face of any activity. The current study focuses on rock type and flow unit classification for the Mishrif reservoir in Iraq's southeast and the study is based on data from five wells that penetrate it. Integration of several methods was used to determine the flow unit based on well log interpretation and petrophysical properties. The flow units were identified using the Quality Index of Rock and the Indicator of Flow Zone. Th
... Show MoreSeventeen samples of Hartha Formation in Balad (1) well, central Iraq, are studied on the basis of stratigraphic ranges of the recorded calcareous nannofossils for twenty species belonging to twelve genera. The studied section reveals three biozones arranged from oldest to youngest as follows; (1) Calculites ovalis Interval Biozone (CC19), (2) Ceratolithoides aculeus Interval Biozone (CC20), (3) Quadrum sissinghii Interval Biozone (CC21). These Biozones are correlated with other calcareous nannofossils biozones from both local and regional sections, leading to conclude the age of the Middle Campanian.
Rerecorded eighteen ostracode species that belong to eleven genera are identified,
... Show MoreMachine learning has a significant advantage for many difficulties in the oil and gas industry, especially when it comes to resolving complex challenges in reservoir characterization. Permeability is one of the most difficult petrophysical parameters to predict using conventional logging techniques. Clarifications of the work flow methodology are presented alongside comprehensive models in this study. The purpose of this study is to provide a more robust technique for predicting permeability; previous studies on the Bazirgan field have attempted to do so, but their estimates have been vague, and the methods they give are obsolete and do not make any concessions to the real or rigid in order to solve the permeability computation. To
... Show MoreThe environmental impact was illustrated by rockslide and erosion on the Duhok Dam and its reservoir. The evaluation of the geotechnical characteristics of the Gercus Formation was conducted. The research plan was divided into three phases, field, laboratory, and office works. The fieldwork included studying all the geological phenomena of the region related to the environmental impact. The laboratory work focused on studying the geotechnical properties of the various rock samples taken from the Gercus Formation. Rocklab program was used to define the geotechnical properties of a rock mass. The results indicated the weak resistance of the Gercus Formation rocks to weathering and erosion processes, as well as their weak resistance to slid
... Show MoreThe central marshes are one of the most important wetlands/ecosystems in the southern area of Iraq. This study evaluates the bed soil's mechanical, physical, and chemical properties at certain southern Iraqi central marshes sites. This was conducted to investigate their types and suitability for enhancing the agricultural reality of most field crops and for construction purposes. Soil samples were collected from 15 sites at 10-100 cm depth. Hence, numerous parameters were determined: index properties, unconfined compressive strength, direct shear strength, consolidation, texture, and sieve analysis, water content, specific gravity, dry density, permeability, pH, total soluble salts (TSS), organic materials (OM) and total
... Show MoreThe studied succession (Lower Miocene-Early Middle Miocene) In central Iraq is distinguished by a wide range of fossils, mostly benthic foraminifera, and other fossils including bivalves, gastropods, echinoids fragments, red algae and coral are also presented. Index fossils of benthic foraminifera have been used for the purpose of determining the age of the Euphrates and Jeribe formations, because of their young age, wide geographical distribution and abundance in the selected wells.
The present study involves four selected wells of Ajil oil field and in terms of the biostratigraphy of the Euphrates, Dhiban, and Jeribe formations depending on benthic foraminifera and other associated fossils. Some of these fossils have a short ve
... Show MoreThe Falluja residents had resorted to the underground water as an alternative to the surface waters of the Euphrates river passing near the city, through digging wells inside gardens of Mosques in the city during spring 2005. The present study aims to indicate the quality of these waters and demonstrates the extent of their suitability for drinking . For this purpose, 21 randomly distributed wells were chosen during August 2005. The water characters were measured ; the average values of 21 wells were as follows : Water temp .(22.6C ْ ◌ ) , EC (4,11 msem .\cm ), pH (7.15 ) and concentration of cations : Na (439mg\l) ;K (275mg\l) ; Li (0,28mg\l), Ba (15.2 mg\l) and (133mg\l). These character is ties were compared with the
... Show MoreThe study includes the epipelic algae in Hemren reservoir, for the period between Januarys to October 2000 .The samples were collected from three selected sites at north, middle and south of reservoir. A total of 96 taxa of epipelic algae were identified. The diatoms were the dominated by 82 taxa represented 85.4% of the total identified species, followed by blue-green algae (cyanophyta) of 6.3 taxa (6%), and then green algae (chlorophyta) of 5.2 taxa (5%). One species was recorded for each crysophyta, euglenophyta and pyrrophyta. The seasonal variation for the cell density showed two peaks during spring and autumn seasons. Few species were dominated during the most studied period such as Achnanthes minutissima, Navicula cryptocephala
... Show MoreMany problems were encountered during the drilling operations in Zubair oilfield. Stuckpipe, wellbore instability, breakouts and washouts, which increased the critical limits problems, were observed in many wells in this field, therefore an extra non-productive time added to the total drilling time, which will lead to an extra cost spent. A 1D Mechanical Earth Model (1D MEM) was built to suggest many solutions to such types of problems. An overpressured zone is noticed and an alternative mud weigh window is predicted depending on the results of the 1D MEM. Results of this study are diagnosed and wellbore instability problems are predicted in an efficient way using the 1D MEM. Suitable alternative solutions are presented
... Show MoreNasiriyah oilfield is located in the southern part of Iraq. It represents one of the promising oilfields. Mishrif Formation is considered as the main oil-bearing carbonate reservoir in Nasiriyah oilfield, containing heavy oil (API 25o(. The study aimed to calculate and model the petrophysical properties and build a three dimensional geological model for Mishrif Formation, thus estimating the oil reserve accurately and detecting the optimum locations for hydrocarbon production.
Fourteen vertical oil wells were adopted for constructing the structural and petrophysical models. The available well logs data, including density, neutron, sonic, gamma ray, self-potential, caliper and resistivity logs were used to calculate the
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