Zubair Formation is one of the richest petroleum systems in Southern Iraq. This formation is composed mainly of sandstones interbedded with shale sequences, with minor streaks of limestone and siltstone. Borehole collapse is one of the most critical challenges that continuously appear in drilling and production operations. Problems associated with borehole collapse, such as tight hole while tripping, stuck pipe and logging tools, hole enlargement, poor log quality, and poor primary cement jobs, are the cause of the majority of the nonproductive time (NPT) in the Zubair reservoir developments. Several studies released models predicting the onset of borehole collapse and the amount of enlargement of the wellbore cross-section. However, assumptions involved in these models have limited their applications to very specific scenarios. In this study, an analytical solution for determination of the volume of collapse during drilling is presented based on changes in the geometry of boreholes. The approach can be used in conjunction with different failure criteria to estimate the collapse onset in the presence of formation strengths and principal stresses. The study highlighted how the integration of information from different sources and disciplines were able to estimate the shear failure induced on the borehole wall during drilling.
In this manuscript has investigated the synthesis of plasma-polymerized pyrrole (C4H5N) nano-particles prepared by the proposed atmospheric pressure nonequilibrium plasma jet through the parametric studies, particularly gas flow rate (0.5, 1 and 1.5 L/min). The plasma jet which used operates with alternating voltage 7.5kv and frequency 28kHz. The plasma-flow characteristics were investigated based on optical emission spectroscopy (OES). UV-Vis spectroscopy was used to characterize the oxidization state for polypyrrole. The major absorption appears around 464.1, 449.7 and 435.3 nm at the three flow rate of argon gas. The chemical composition and structural properties of the
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Soft clays are generally sediments deposited by rivers, seas, or lakes. These soils are fine-grained plastic soils with appreciable clay content and are characterized by high compressibility and low shear strength. To deal with soft soil problems there is more than one method that can be used such as soil replacement, preloading, stone column, sand drains, lime stabilization and Prefabricated Vertical Drains, PVDs. A numerical modeling of PVD with vacuum pressure was analyzed to investigate the effect of this technique on the consolidation behavior of fully and different depths of partially saturated soft soils. Laboratory experiments were also conducted by using a specially-designed large consol
... Show MoreObjectives: The current study aims at identifying the level of perceived stress among nursing college students and determining the factors associated with stress they have. Methodology: A cross-sectional descriptive study initiated for the period on November 1st, 2014 to May 1st, 2015. The study has been conducted on the undergraduate nursing college students / University of Baghdad. The sample of the study was consisted of (128) students who were selected purposively. The questionnaire of the study was adopted and modified for the present study which consisted of socio-demographic data and the scale of
The aim of the research was designing a nutritional program with amino acids well as designing exercises for muscular strength training for youth female badminton players. In addition to that the researcher aimed at identifying the effect of amino acid accompanied with muscular training on some physiological indicators in youth female badminton players. The researcher used the experimental method. The subjects were (7) youth female badminton players from the Armenian badminton club. Many physiological tests were conducted including PWC170 and Vo2Max. The data was collected and treated using proper statistical operations to conclude that amino acid accompanied with muscular ability training have a positive effect on some physiological indica
... Show MoreObjective: One of the most important practical deficiencies of present denture base materials is fracture, therefore many
attempts have been made to reinforce of the repaired denture base resin. A desirable objective for this service is to obtain
optimum strength for repairs, which can be achieved by making available a good bond between original and repaired
materials.
Methodology: The present study was carried out to evaluate and compare the transverse strength of acrylic specimens
repaired by two different materials (hot-cure and cold-cure acrylic resin). A total of 50 specimens were prepared by hot
(40) repair: (10) by hot with retention bead, (10) by cold with retention bead and (10) repair by hot only, (10) repair
Background: Surface treatment of machined dental zirconia for enhancement of the adhesion to resin cement, using Er,Cr:YSGG Laser. Materials and Methods: Total number of 42 zirconia disc specimens (9 mm diameter, and 2 mm height) was sintered according to the manufacturer instruction. They are divided into six groups, each group of seven samples. Laser groups (Experiment parameters) were depend on laser total irradiation time, pulse duration, and power. Group (A): 20 sec., 60 µs pulse duration. Group (B): 30 sec., 60 µs pulse duration. Group (C): 40 sec., 60 µs pulse duration. Group (D): 20 sec., 700 µs pulse duration. Group (E): 30 sec., 700 µs pulse duration, with different powers used (1, 1
... Show MoreThe current research dealt with the development of sciences and arts over the course of human history, and the development of sciences with their natural and human trends are important areas in developing the knowledge and application base for industrial product design and design in its various fields. Bionic science is one of the sciences that works on applying biological methods and systems found in nature to study and design engineering systems and modern technology, and for industrial products to be highly efficient, durable and resistant to natural variables in daily life for use. The transfer of technology between life forms and industrial products is desirable because the processes of development at the level of science in general
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Carbon fiber reinforced polymers (CFRP) were widely used in strengthening reinforced concrete members
in the last few years, these fibers consist mainly of high strength fibers which increase the member capacity in addition to changing the mode of failure of the reinforced concrete beams. Experimental and theoretical investigations were carried to find the behavior of reinforced concrete beams strengthened by CFRP in shear and bending. The experimental work included testing of 12 beams divided into 4 groups; each group contains 3 beams. The following parameters were taken into consideration: - Concrete crushing strength. - CFRP strengthening location (shear strengthening and both shear and flexure strengthening). Reinforced beams were
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Porcelain is one of the most important ceramic materials with a wide range of traditional and technical applications. Since most mixtures of porcelain have a high sintering temperature, bentonite has been added in this research to improve the characteristics of sintering and burning. The porcelain mixture consisted of the following Iraqi raw materials: 30% wt kaolin, 30 wt% non-plastic clay (grog), 10% wt sodium feldspar, 10 wt% potassium feldspar and 20 wt% flint. After the mechanical mixing process and transfer the powder mixture to the slurry by adding distilled water, then different weight percentage of the sodium bentonite(0, 2.5, 5, 7.5 and 10) wt% was added. The specimens were prepared by using the solid casting m
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In this search, Ep/SiO2 at (3, 6, 9, 12 %) composites is prepared by hand Lay-up method, to measure the change in the thermal conductivity and Impact Strength of epoxy resin before and after immersion in H2SO4 Solution with a 0.3N for 10 days. The results before immersion decreases with the increase of the weight ratios of the reinforcement material (SiO2), It changed from (82.6×10-2 to 38.7×10-2 W/m.°C) with change weight ratios from (3 to 12) % respectively, but after immersion time in the chemical solution where it was (65.6×10-2 W/m.°C) at the weight ratios (6 %) and became (46.6 × 10-2 W/m.°C) after immersion in sulfuric acid. The results of the Impact strength decreased by increasing the percentage weight ratio, it changed f
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