As the reservoir conditions are in continuous changing during its life, well production rateand its performance will change and it needs to re-model according to the current situationsand to keep the production rate as high as possible.Well productivity is affected by changing in reservoir pressure, water cut, tubing size andwellhead pressure. For electrical submersible pump (ESP), it will also affected by numberof stages and operating frequency.In general, the production rate increases when reservoir pressure increases and/or water cutdecreases. Also the flow rate increase when tubing size increases and/or wellhead pressuredecreases. For ESP well, production rate increases when number of stages is increasedand/or pump frequency is

   This study aims to determine the petrophysical characteristics of the three wells in the Kifl Oilfield, central Iraq. The well logs were used to characterize hydrocarbon reservoirs to assess the hydrocarbon prospectivity, designate hydrocarbon and water-bearing zones, and determine the Nahr Umr Formation's petrophysical parameters. The Nahr Umr reservoir mainly consists of sandstone at the bottom and has an upper shale zone containing a small proportion of oil. The geophysical logs data from three oil wells include gamma-ray, resistivity, neutron, density, acoustic, and spontaneous potential logs. A gamma-ray log was employed for lithology differentiation, and a resistivity log was used to determine the response of distinct zones

The petrophysical analysis is very important to understand the factors controlling the reservoir quality and production wells. In the current study, the petrophysical evaluation was accomplished to hydrocarbon assessment based on well log data of four wells of Early Cretaceous carbonate reservoir Yamama Formation in Abu-Amood oil field in the southern part of Iraq. The available well logs such as sonic, density, neutron, gamma ray, SP, and resistivity logs for wells AAm-1, AAm-2, AAm-3, and AAm-5 were used to delineate the reservoir characteristics of the Yamama Formation. Lithologic and mineralogic studies were performed using porosity logs combination cross plots such as density vs. neutron cross plot and M-N mineralogy plot. Thes

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 paramete

      The reservoir characterization of Lower Qamchuqa (Shu'aiba) Formation (Aptian) is studied at the well BH-86 of Bai- Hassan Oilfield in Kirkuk area, Northern Iraq. The lithological study (of 91 thin sections) revealed that the formation consists of shaly limestone, a thin bed of marl within the limestone, and dolomitic limestone. Four petrographic microfacies were noticed Lime mudstone microfacies, Dolomudstone microfacies, Lime wackestone microfacies, subdivided into benthonic foraminifera lime wackestone submicrofacies and bioclasts lime wackestone submicrofacies, and the last microfacies is the Lime packstone microfacies, which is subdivided into pelloidal lime packstone submicrofacies and Orbitolina lime packstone microfaci

In the region of the north of Iraq using the method of analyzing thin section microfacies to 38 of rockyslices which were gathered from a place near Aqra city. These slides are divided into seven microfacies depending on lithologcal component and fossils.

1) Dolostone facies.

2)Recrystallized bioclastic wackestone facies.

3) Bioclastic packstone microfacies

4)Sucrosic dolomite facies.

 5) Bioclastic grainstone in microfacies.

 According to water energy, these facies were divided to three zone:

1. a) Low energy environment.
2. b) Transitional zone.
3. c) High energy environment.

Twenty nine core samples were taken from Ratawi 7 Oil well according to the presence of oil in formation and availability of core samples. This well is located in the province of Basra/southern Iraq. The samples were collected from Yamama Formation. The core samples are taken from the well at different depths, ranging between (3663m-3676m). The range of Vp for these core samples is (668-4017 m/sec) and its average is (1779 m/sec), While the range of Vs is (291-1854 m/sec) and its average is (796 m/sec). In the current study the ultrasonic method is conducted to measure Vp, Vs as well as some petrophysical properties for core samples and some elastic moduli such as (Young's modulus, Bulk modulus, Shear modulus, Poisson's ratio and Lame's

In this paper the queuing system (M/Er/1/N) has been considered in equilibrium. The method of stages introduced by Erlang has been used. The system of equations which governs the equilibrium probabilities of various stages has been given. For general N the probability of j stages of service are left in the system, has been introduced. And the probability for the empty system has been calculated in the explicit form.

The Nahr Umr Formation, one of the most important Cretaceous formations and one of the main generating reservoirs in southern Iraq and neighboring regions, was chosen to study and estimate its petrophysical properties using core plugs, lithofacies, and well logs from five wells in the Noor oilfield. Reservoir properties and facies analyses are used to divide the Nahr Umr formation into two-member (limestone in the upper part and main sandstone in the lower). Limestone members are characterized by low reservoir properties related to low effective porosity and permeability while the main sandstone member is considered as a reservoir. Four lithofacies were recognized in the main sandstone member of the Nahr Umr Formation according to petrog