The shale volume is one of the most important properties that can be computed depending on gamma ray log. The shale volume of Mishrif Formation (carbonate formation from middle Cenomanian- early Turonian) was studied for the regional area of the middle and southern parts of Iraq. The gamma ray log data from seventeen wells ( Kf-3,Kf-4, Ad-1,Ad -2,Dh-1, Bu-47, Ns-2, Ns-4, Am-1,Am-2,Hf-2,Hf-115,Mj-3,Mj-15, Su-7,Wq-15 and Lu-7) distributed in the study area were used to compute the shale volume of Mishrif Formation. From the available data of the considered wells, a regional isopach map of Mishrif Formation was obtained. The isopach map indicates that the maximum thickness of Mishrif Formation is located at the eastern part of the study area. The results of the CPI and the shale volume map, which were computed using the Techlog and surfer software, show that the maximum value of shale volume is located at the southern part of the study area (Su-7 well), while the minimum value is at the eastern part (Hf-2well). According to the classification of Kamel and Mabrouk (2003), Mishrif Formation seems to be a Shaly Formation in the study area, except Halfaya oil field at the eastern part of the study area, which seems as a Clear Formation. The top map of the shale marker bed, which appears in most studied wells, shows a regional trend of the formation toward the northeast. According to the variation of the thickness of the shale marker bed, the study area is divided into four zones.
Mishrif Formation was deposited during The Cenomanian-Early Turonian, which has been studied in selected Tuba and Zubair OilFields, these wells (TU-5, TU-24, TU-40, ZB-41, ZB-42, and ZB-46) are located within Mesopotamian basin at southern Iraq and considered as a major carbonate reservoir in Iraq and the Arabian Gulf. The palaeontological investigations mainly depending on benthonic foraminifera of the studied wells of Tuba and Zubair Oilfields in Mishrif Formation, twenty-four species belonging to fourteen genera are recognized of benthonic foraminifera, which has been recognized through this study, especially benthonic foraminiferal, indicating four zones as follows:
A comparison was conducted between two wells, Kt-1and Kt-2, in Kumait and two wells, Du-1and Du-2, in Dujaila oil fields that belong to Mishrif formation, southern Iraq. Seismic inversion method was employed to detect oil and water reservoirs. The comparison included the behavior of acoustic impedance (AI) of fluids and the lithology with related petrophysical properties. The values of water saturation, Shale volume (Vsh), and effective porosity were compared between the AI, two fluid reservoirs. It was found that the AI value for the oil reservoir unit is relatively low to medium, whereas it was relatively medium for the water reservoir. Effective porosity value showed, in general, an increase in the oil reservoir and
... Show MoreThe seismic method depends on the nature of the reflected waves from the interfaces between layers, which in turn depends on the density and velocity of the layer, and this is called acoustic impedance. The seismic sections of the East Abu-Amoud field that is located in Missan Province, south-eastern Iraq, were studied and interpreted for updating the structural picture of the major Mishrif Formation for the reservoir in the field. The Mishrif Formation is rich in petroleum in this area, with an area covering about 820 km2. The horizon was calibrated and defined on the seismic section with well logs data (well tops, check shot, sonic logs, and density logs) in the interp
... Show MoreThis research is an attempt to solve the ambiguity associated with the stratigraphic setting of the main reservoir (late Cretaceous) of Mishrif Formation in Dujaila oil field. This was achieved by studying a 3D seismic reflection post-stack data for an area of 602.62 Km2 in Maysan Governorate, southeast of Iraq. Seismic analysis of the true amplitude reflections, time maps, and 3D depositional models showed a sufficient seismic evidence that the Mishrif Formation produces oil from a stratigraphic trap of isolated reef carbonate buildups that were grown on the shelf edge of the carbonate platform, located in the area around the productive well Dujaila-1. The low-frequency attribute illustrated tha
... Show MoreThe current study includes building (CPI) & Petrophysical Evaluation of the Mishrif Formation (Cenomanian-Early Turonian) in Tuba oilfield, southern Iraq by using Interactive Petrophysics Program v3.5 (IP) to evaluate different logs parameters that control the reservoir quality of Mishrif Formation such as shale volume, effective porosity, and water saturation. Mishrif Formation is subdivided into several units, which are characterized by different reservoir properties. These units are Top of Mishrif, MA, CR2, MB1, and MB2.The results of computer processed interpretation (CPI) show that the major reservoir unit are (MB1 and MB2), which are characterized by high effective porosity and oil saturation. In addition, these uni
... Show MoreStable isotopes 18O/16O and 13C/12C in the carbonate rocks of the Mishrif Formation are examined here to define the depositional characters in the basin includes paleo temperatures and paleo depth.
The Mishrif formation (Cenomanian – Early Turonian) has extensive distribution in Iraq and Middle East. Mishrif Formation composed of organic detrital limestone. Four boreholes in four oilfields, Noor – well (11), Amarah – well (14), Buzurgan – well (24), Halfaya – well (8), in south east of Iraq have been studied.
The studied samples have negative δ18O isotope values studied well, with Average (-4.11‰), (
... Show MoreWell log analysis of selected sections in southern Iraq revealed that primary porosity is the most effective parameters. Secondary porosity seems to be related mainly to dissolution and dolomatization. The Hartha Formation has good water saturation and low production except in the eastern and central part of the study area. Two reservoir units were recognized in Mj-2 whereas only one in Ga-1.
The values of velocity deviation in most wells show high positive deviation, this may indicate relatively high velocity in regard to porosity where pores are commonly not connected such as in interaparticle or moldic porosity. A positive deviation also may indicate low permeability. Negative deviation zone (Only in Ak-1) may represent caving or i
The seismic method depends on the nature of the reflected waves from the interfaces between layers, which in turn depends on the density and velocity of the layer, and this is called acoustic impedance. The seismic sections of the East Abu-Amoud field that is located in Missan Province, south-eastern Iraq, were studied and interpreted for updating the structural picture of the major Mishrif Formation for the reservoir in the Abu-amoud field. The Mishrif Formation is rich in petroleum in this area, with an area covering about 820 km2. The seismic interpretation of this study was carried out utilizing the software of Petrel-2017. The horizon was calibrated and defined on t
... Show MoreThe EMERGE application from Hampsson-Russell suite programs was used in the present study. It is an interesting domain for seismic attributes that predict some of reservoir three dimensional or two dimensional properties, as well as their combination. The objective of this study is to differentiate reservoir/non reservoir units with well data in the Yamama Formation by using seismic tools. P-impedance volume (density x velocity of P-wave) was used in this research to perform a three dimensional seismic model on the oilfield of Nasiriya by using post-stack data of 5 wells. The data (training and application) were utilized in the EMERGE analysis for estimating the reservoir properties of P-wave ve
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