Shear wave velocity is an important feature in the seismic exploration that could be utilized in reservoir development strategy and characterization. Its vital applications in petrophysics, seismic, and geomechanics to predict rock elastic and inelastic properties are essential elements of good stability and fracturing orientation, identification of matrix mineral and gas-bearing formations. However, the shear wave velocity that is usually obtained from core analysis which is an expensive and time-consuming process and dipole sonic imager tool is not commonly available in all wells. In this study, a statistical method is presented to predict shear wave velocity from wireline log data. The model concentrated to predict shear wave velocity from petrophysical parameters and any pair of compressional wave velocity, porosity and density in carbonate rocks. The established method can estimate shear wave velocity in carbonate rocks with a correlation coefficient of close to unity.
Missing data is one of the problems that may occur in regression models. This problem is usually handled by deletion mechanism available in statistical software. This method reduces statistical inference values because deletion affects sample size. In this paper, Expectation Maximization algorithm (EM), Multicycle-Expectation-Conditional Maximization algorithm (MC-ECM), Expectation-Conditional Maximization Either (ECME), and Recurrent Neural Networks (RNN) are used to estimate multiple regression models when explanatory variables have some missing values. Experimental dataset were generated using Visual Basic programming language with missing values of explanatory variables according to a missing mechanism at random general pattern and s
... Show MoreAhdeb oil field is located in the central block of Mesopotamia plain in Iraq. It has three domes AD-1, AD-2, and AD-4.The current study represents characterization of carbonate Mishrif reservoir (Cenomanian-Early Turonian) in three wells (AD-A,AD-B,AD-C) at southern dome of Ahdeb oil field. Petrophysical properties were calculated using available well logs data such as neutron, density, sonic, gamma ray, resistivity and self-potential logs. These logs are digitized and then environmental corrections and interpretations were carried out using Techlog software. Petrophysical parameters such as shale volume, porosity, water saturation, hydrocarbon saturation, bulk water volume, etc. were determined and interpreted and illustrate
... Show MoreThe harvest of hydrocarbon from the depleted reservoir is crucial during field development. Therefore, drilling operations in the depleted reservoir faced several problems like partial and total lost circulation. Continuing production without an active water drive or water injection to support reservoir pressure will decrease the pore and fracture pressure. Moreover, this depletion will affect the distribution of stress and change the mud weight window. This study focused on vertical stress, maximum and minimum horizontal stress redistributions in the depleted reservoirs due to decreases in pore pressure and, consequently, the effect on the mud weight window. 1D and 4D robust geomechanical models are
Porosity and permeability are the most difficult properties to determine in subsurface reservoir characterization. The difficulty of estimating them arising from the fact that porosity and permeability may vary significantly over the reservoir volume, and can only be sampled at well location. Secondly, the porosity values are commonly evaluated from the well log data, which are usually available from most wells in the reservoir, but permeability values, which are generally determined from core analysis, are not usually available. The aim of this study is: First, to develop correlations between the core and the well log data which can be used to estimate permeability in uncored wells, these correlations enable to estimate reservoir permeabil
... Show MoreThis study was the first of its kind on the Dejiala River, which is considered one of the main branches of the Tigris River in Wasit Province. Therefore, the study aimed to investigate of some physical and chemical properties of water in the Dejiala River. Monthly sampling stations were conducted for 12 months, which was starting from January to December 2016, during those five stations was chosen which divided along about 58 Km of river; each station was located at a distance of ±10 Km. The results of the study showed a clear correlation between air and water temperature in all stations. Turbidity was recorded a value ranging from 2.36-116 NTU. It was found that the water of the Dejiala was Oligohaline, weak al
... Show MoreThe Climatic parameters for the years (1985-2015) were collected from Baghdad
meteorological station and then were applied to evaluate the climatic conditions for
the Al-Yusufyiah area south Baghdad. The total annual rainfall is (119.65 mm),
while the total annual evaporation is (3201.7 mm), relative humidity is (43.62%),
sunshine (8.76 h/day), temperature (23.28 C◦) and wind speed (3.06 m/sec). Climate
of the study area is described as an arid according to classification of (Kettaneh and
Gangopadhyaya, 1974), (Mather, 1973), and (Al-Kubaisi, 2004). Mean monthly
water surplus for the period (1985-2015) was recorded in the study area about (4.7
mm) in November, (11.67 mm) in December, (20.56 mm) in January and (6
The sequence in the upper part of the Balambo Formation is composed mainly of limestone alternating with marly limestones and dark grey shale in the Bosheen section (eastern Sulaymaniyah, northeastern Iraq) and has been studied in terms of its rare earth element (REE) content. The REEs are very low compared to modern marine sediments. They are depletion in LREEs, and enrichment in HREEs and (La/Yb)N in the studied rocks, indicating that these sediments retained the REEs pattern of marine waters. The negative Ce anomaly reflects direct sedimentation from marine waters under anoxic conditions with the contribution of terrigenous clays. The positive correlation of ∑REEs with Al, Ti, and Y, and the negative correlation of ∑REE
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In past years, structural pavement solution has been combined with destructive testing; these destructive methods are being replaced by non-destructive testing methods (NDT). Because the destructive test causes damage due to coring conducted for testing and also the difficulty of adequately repairing the core position in the field. Ultrasonic pulse velocity was used to evaluate the strength and volumetric properties of asphalt concrete, of binder course. The impact of moisture damage and testing temperature on pulse velocity has also been studied. Data were analyzed and modeled. It was found that using non-destructive testing represented by pulse velocity could be useful to predict the quality of asphalt c
... Show MoreAbstract: -
The concept of joint integration of important concepts in macroeconomic application, the idea of cointegration is due to the Granger (1981), and he explained it in detail in Granger and Engle in Econometrica (1987). The introduction of the joint analysis of integration in econometrics in the mid-eighties of the last century, is one of the most important developments in the experimental method for modeling, and the advantage is simply the account and use it only needs to familiarize them selves with ordinary least squares.
Cointegration seen relations equilibrium time series in the long run, even if it contained all the sequences on t
... Show MoreThe aim of this work is to evaluate the onc-electron expectation values < r > from the radial electronic density funetion D(r) for different wave ?'unctions for the 2s state of Li atom. The wave functions used were published in 1963,174? and 1993 , respectavily. Using " " ' wave function as a Slater determinant has used the positioning technique for the analysis open shell system of Li (Is2 2s) State.