Wellbore instability problems cause nonproductive time, especially during drilling operations in the shale formations. These problems include stuck pipe, caving, lost circulation, and the tight hole, requiring more time to treat and therefore additional costs. The extensive hole collapse problem is considered one of the main challenges experienced when drilling in the Zubair shale formation. In turn, it is caused by nonproductive time and increasing well drilling expenditure. In this study, geomechanical modeling was used to determine a suitable mud weight window to overpass these problems and improve drilling performance for well development. Three failure criteria, including Mohr–Coulomb, modified Lade, and Mogi–Coulomb, were used to predict a safe mud weight window. The geomechanical model was constructed using offset well log data, including formation micro-imager (FMI) logs, acoustic compressional wave, shear wave, gamma ray, bulk density, sonic porosity, and drilling events. The model was calibrated using image data interpretation, modular formation dynamics tester (MDT), leak-off test (LOT), and formation integrity test (FIT). Furthermore, a comparison between the predicted wellbore instability and the actual wellbore failure was performed to examine the model's accuracy. The results showed that the Mogi–Coulomb failure and modified Lade criterion were the most suitable for the Zubair formation. These criteria were given a good match with field observations. In contrast, the Mohr–Coulomb criterion was improper because it does not match shear failure from the caliper log. In addition, the obtained results showed that the inappropriate mud weight (10.6 ppg) was the main cause behind wellbore instability problems in this formation. The optimum mud weight window should apply in Zubair shale formation ranges from 11.5 to 14 ppg. Moreover, the inclination angle should be less than 25 degrees, and azimuth ranges from 115 to 120 degrees northwest-southeast (NE–SW) can be presented a less risk. The well azimuth of NE–SW direction, parallel to minimum horizontal stress (Shmin), will provide the best stability for drilling the Zubair shale formation. This study's findings can help understand the root causes of wellbore instability in the Zubair shale formation. Thus, the results of this research can be applied as expenditure effectiveness tools when designing for future neighboring directional wells to get high drilling performance by reducing the nonproductive time and well expenses.
Noor oil field is one of smallest fields in Missan province. Twelve well penetrates the Mishrif Formation in Noor field and eight of them were selected for this study. Mishrif formation is one of the most important reservoirs in Noor field and it consists of one anticline dome and bounded by the Khasib formation at the top and the Rumaila formation at the bottom. The reservoir was divided into eight units separated by isolated units according to partition taken by a rounding fields.
In this paper histograms frequency distribution of the porosity, permeability, and water saturation were plotted for MA unit of Mishrif formation in Noor field, and then transformed to the normal distribution by applying the Box-Cox transformation alg
... Show MoreIn this paper, mesoscale modeling is performed to simulate and understand fracture behavior of two concrete composites: cement and asphalt concrete using disk-shaped compact tension (DCT) tests. Mesoscale models are used as alternative to macroscale models to obtain better realistic behavior of composite and heterogeneous materials such as cement and asphalt concrete. In mesoscale models, aggregate and matrix are represented as distinct materials and each material has its characteristic properties. Disk-shaped compact tension test is used to obtain tensile strength and fracture energy of materials. This test can be used as a better alternative to other tests such as three points bending tests because it is more convenient for both field and
... Show MoreReservoir characterization is an important component of hydrocarbon exploration and production, which requires the integration of different disciplines for accurate subsurface modeling. This comprehensive research paper delves into the complex interplay of rock materials, rock formation techniques, and geological modeling techniques for improving reservoir quality. The research plays an important role dominated by petrophysical factors such as porosity, shale volume, water content, and permeability—as important indicators of reservoir properties, fluid behavior, and hydrocarbon potential. It examines various rock cataloging techniques, focusing on rock aggregation techniques and self-organizing maps (SOMs) to identify specific and
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Abstract
The net profit reported in the annual financial statements of the companies listed in the financial markets, is considered one of the Sources of information relied upon by users of accounting information in making their investment decisions. At the same time be relied upon in calculating the bonus (Incentives) granted to management, therefore the management of companies to manipulate those numbers in order to increase those bonuses associated to earnings, This practices are called earnings management practices. the manipulation in the figures of earnings by management will mislead the users of financial statements who depend on reported earnings in their deci
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This study aims to identify maternal death cases caused by Coronavirus infection 2019 pneumonia, including disease progression, fetal consequences, and the fatality cause.
Patients and methodology: A retrospective case collection of Iraqi pregnant women in their second and third trimesters diagnosed with COVID-19 pneumonia and died due to it.
The four cases were all of a young age, had a brief complaint period, and had no comorbidities. Fever, dyspnea, and fatigue were the most common symptoms. Hypoxia was present in all cases and was the cause of mortality in three cases, with thromboembolism being a potential cause in the fourth. Prelabour membrane breakup, fetal growth restriction, and fetal death are al
... Show MoreMany oil and gas processes, including oil recovery, oil transportation, and petroleum processing, are negatively impacted by the precipitation and deposition of asphaltene. Screening methods for determining the stability of asphaltenes in crude oil have been developed due to the high cost of remediating asphaltene deposition in crude oil production and processing. The colloidal instability index, the Asphaltene-resin ratio, the De Boer plot, and the modified colloidal instability index were used to predict the stability of asphaltene in crude oil in this study. The screening approaches were investigated in detail, as done for the experimental results obtained from them. The factors regulating the asphaltene precipitation are different fr
... Show MoreThe present research included sampling and analysis of 41 soil samples , the samples cover various areas of Nasiriyah city (industrial,commercial,residential and agricultural ) to estimate pollution levels of lead element and determine the correlation between lead concentration and natural factors in soil which represent sedimentary organic matter content, granular gradient, clay minerals and non-clay minerals . The results of the current study showed that the average concentration of lead in the soil samples was 61.12 ppm , it was noticed an increase in the concentration of lead in environmental components in the area of this study especially in residential , industrial and commercial location and the impact of natural factors of the so
... Show MoreThe external shocks are one of the phenomena that the Iraqi economy is exposed to over a period of time. It is referred to as changes and events that come from outside the economic system and extends to many economic variables. However, foreign direct investment may be severely affected due to the extreme sensitivity to changes and local and international developments. This type of trauma and its characteristics to help manage and cope with external shocks, and in order to avoid the standard problems experienced by some models of simple linear regression, multi-linear regression models were used with variables Scientific and other dummy variables .
The study foun
... Show MoreIn this paper, game theory was used and applied to the transport sector in Iraq, as this sector includes two axes, the public transport axis and the second axis the private transport axis, as each of these axes includes several types of transport, namely (sea transport, air transport, land transport, transport by rail, port transport) and the travel and tourism sector, as public transport lacks this sector, as the competitive advantage matrix for the transport sector was formed and after applying the MinMax-MaxMin principle to the matrix in all its stages, it was found that there was an equilibrium point except for the last stage where the equilibrium point was not available Therefore, the use of the linear programming method was
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