Reservoir unit classifications can be used in reservoir characterization of carbonate reservoirs where there is variability in the distribution of petrophysical properties. This requires the integration of geological and petrophysical data at different scales. In this study, cores and thin sections from Yamama Formation (Lower Cretaceous) at Gharaf oilfield, southern Iraq, were studiedto identify reservoir units.

     Ninereservoir units (units Y1 to Y9) were identified based on petrophysical evaluation by using interactive Petrophysics program (IP) software and depositional environments and related microfacies.The unit Y2 have the highest reservoir quality, which consists of grain-supported facies(packstone a

      The Mishrif Formation (Cenomanian – Early Turonian) is an important geologic formation in southern Iraq due to its petrophysical properties and geographic extensions, making it a good reservoir of hydrocarbons. Petrophysical properties of the Mishrif Formation in the current study at the Nasiriya oil field were determined from the interpretation of three open-hole logs data of (NS-1, NS-2, and NS-3) wells.

The results of the Mishrif petrophysical evaluation showed that the formation consists of five variable units (CRI, MA, CRII, MB1 and MB2), each one characterized by distinct petrophysical characteristics.

The upper (MA) and lower (MB) units were determined using electrical, porosity and gamma-ray logs. A sha

    The Hartha Formation is a major carbonate succession deposited during the Late Campanian period. The current study depends on four selected wells (EB 1, 2, 4 and 30) within the East Baghdad oil field to study electrofacies and petrophysical properties related to the reservoir characterization.

The Hartha Formation is divided into three electro-facies units using GR and SP logs in Petrel software. The upper unit of the Hartha Formation is composed mainly of limestone. The middle unit is composing of thick layers of shale. The lower unit is composed mainly of limestone with few shale layers. The three units are divided into three types of rocks in relation to the total porosity: 1. High-moderate active porosity rocks (type I)

      The current study includes preparing a geometric proposal of the main parameters that must be worked within a seismic reflection survey to prepare a three-dimensional subsurface image. This image represents the Siba oil field located in Basra, southern Iraq. The results were based on two options for selecting these approved elements to create a three-dimensional image of the Mishrif, Zubair and Yamama formations as well as the Jurassic and Permian Khuff and the pre-Khuff reservoir area. The first option is represented in the geometry in option -1 is 12 lines, 6 shots, and 216 chs. The receiver density is 66.67 receivers / km², so the shot density is the same. Total shots are 21000, which is the same number of receiv

Injana Formation is the most extended geological formation in Salahaddin Governorate/ Iraq. About 10% of the studied area is covered by the outcrops of the formation as a recharge area. The formation is a subsurface within the unsaturated zone in 5% of the total studied area, while it exists within the saturated zone in about 85%; it is a major confined groundwater aquifer. Therefore, the hydrogeological system of the layers needs to be re-evaluated to describe the successions of aquifers and confining layers and their relation with each other.

The lithology, depths, water table, saturated thickness, hydraulic characteristics of the aquifers, and the lateral and vertical variations of these characteristics were adopted to classif

The reserve estimation process is continuous during the life of the field due to risk and inaccuracy that are considered an endemic problem thereby must be studied. Furthermore, the truth and properly defined hydrocarbon content can be identified just only at the field depletion. As a result, reserve estimation challenge is a function of time and available data. Reserve estimation can be divided into five types: analogy, volumetric, decline curve analysis, material balance and reservoir simulation, each of them differs from another to the kind of data required. The choice of the suitable and appropriate method relies on reservoir maturity, heterogeneity in the reservoir and data acquisition required. In this research, three types of rese