One of the wellbore instability problems in vertical wells are breakouts in Zubair oilfield. Breakouts, if exceeds its critical limits will produce problems such as loss circulation which will add to the non-productive time (NPT) thus increasing loss in costs and in total revenues. In this paper, three of the available rock failure criteria (Mohr-Coulomb, Mogi-Coulomb and Modified-Lade) are used to study and predict the occurrence of the breakouts. It is found that there is an increase over the allowable breakout limit in breakout width in Tanuma shaly formation and it was predicted using Mohr-Coulomb criterion. An increase in the pore pressure was predicted in Tanuma shaly formation, thus; a new mud weight and casing programs are proposed to overcome such problems in the drilling operations in field developments plans.
The aim of this research is to study the influence of additives on the properties of soap greases, such as lithium, calcium, sodium, lithium-calcium grease, by adding varies additives, such as graphite, molybdenum disulfide, carbon black, corrosion inhibitor, and extreme pressure.
These additives have been added to grease to obtain the best percentages that improve the properties of grease such as load carrying, wear resistance, corrosion resistance, drop point, and penetration.
The results showed the best weight percentages to all types of grease which give good properties are 1.5% extreme pressure additive, 3% graphite, 1% molybdenum disulfide, 2.5% carbon black.
The other hand, the best weight percentage for corrosion inhibit
In this research, a numerical simulation was conducted to study the behavior of the scouring pattern and the effect of spacing between bridge piers at specified hydraulic conditions such as velocity, depth of flow, and the sediment effective diameter. Moreover, the cross-section shape of piers and their effect on the scouring depth around bridge piers was studied, using Computational Fluid Dynamics (CFD), ANSYS (Fluent) software. A comparison of the simulation results obtained with previous laboratory investigations was done to verify the validity of the numerical model. Generally, the scour pattern using the CFD software gave good agreement with the experimental study. A reversed pro
Rutting is a predominant distress in asphalt pavements, particularly in hot climatic regions. This study systematically investigated the high-temperature performance of hot mix asphalt modified with five nanomaterials, namely, nano-silica (NS), nano-alumina (NA), nano-titanium (NT), nano-zinc (NZ), and carbon nanotubes (CNTs), under consistent laboratory conditions. Modification dosages were selected up to 10% for NS, NA, and NT, and up to 5% for NZ and CNTs. The experimental methodology comprised the following: (i) binder rheological characterization through rotational viscosity, G*/sinδ, and multiple stress creep recovery (MSCR) to quantify rutting susceptibility; (ii) chemical and microstructural assessments using Fourier transf
... Show MoreIn the case where a shallow foundation does not satisfy with design requirements alone, the addition of a pile may be suitable to improve the performance of the foundation design. The lack of in-situ data and the complexity of the issues caused by lagging in the research area of pile foundations are notable. In this study, different types of piles were used under the same geometric conditions to determine the load-settlement relationships with various sandy soil relative densities. The ultimate pile capacity for each selected pile is obtained from a modified California Bearing Ratio (CBR) machine to be suitable for axial pile loading. Based on the results, the values of Qu for close-ended square pile were increased by 15
... Show MoreIn recent years, the world witnessed a rapid growth in attacks on the internet which resulted in deficiencies in networks performances. The growth was in both quantity and versatility of the attacks. To cope with this, new detection techniques are required especially the ones that use Artificial Intelligence techniques such as machine learning based intrusion detection and prevention systems. Many machine learning models are used to deal with intrusion detection and each has its own pros and cons and this is where this paper falls in, performance analysis of different Machine Learning Models for Intrusion Detection Systems based on supervised machine learning algorithms. Using Python Scikit-Learn library KNN, Support Ve
... Show MoreEthanol as a solvent, a precursor of titanium isopropoxide and a stabilizer of either hydrochloric acid or ammonium hydroxide was used to prepare a titanium dioxide aqueous solution. The aqueous solutions with different values of pH and the morphology of the resultant reaction of the nanoparticles of titanium dioxide were investigated. The X-ray diffraction showed that at low temperatures and with acidic solutions, rutile structures are more favorable to grow on titanium dioxide synthesized, while at low and average temperatures and with base solutions, anatase phase is more pronounced. The crystalline form and the re-confirmation of the crystallite size growth were observed by the scanning electron microscopy. The atomi
... Show MoreWaste materials might be utilized in various applications, such as sustainable roller compacted concrete pavements (RCCP), to lessen the negative environmental consequences of construction waste. The impacts of utilizing (brick, thermostone, granite, and ceramic) powders on the mechanical characteristics of RCCP are investigated in this study. To achieve this, the waste materials were crushed, grounded, and blended before being utilized as filler in the RCCP. After the mixes were prepared, compressive strength, splitting tensile strength, flexural strength, water absorption, density, and porosity were all determined. According to the research results, adding some of these powders, mainly brick and granite powder, enhances the mechanical
... Show MoreEthanol as a solvent, a precursor of titanium isopropoxide and a stabilizer of either hydrochloric acid or ammonium hydroxide was used to prepare a titanium dioxide aqueous solution. The aqueous solutions with different values of pH and the morphology of the resultant reaction of the nanoparticles of titanium dioxide were investigated. The X-ray diffraction showed that at low temperatures and with acidic solutions, rutile structures are more favorable to grow on titanium dioxide synthesized, while at low and average temperatures and with base solutions, anatase phase is more pronounced. The crystalline form and the re-confirmation of the crystallite size growth were observed by the scanning electron microscopy. The atomic force micr
... Show MoreBackground: The isthmus is a difficult area in the root canal complex to manage. The research aimed to evaluate the efficiency of three different obturation techniques (lateral condensation, EandQ (thermoplasticized gutta percha system) and Soft Core (thermoplasticized core carrier gutta percha system)) to obturate the isthmus area of roots prepared by two different instrumentation techniques (rotary ProTaper universal and ProTaper Next systems). Material and method: Sixty freshly extracted teeth were randomly divided into two main groups (A and B) of 30 teeth each. Group A was prepared by rotary ProTaper Universal whereas group B was prepared by ProTaper Next system. Each main group was then randomly subdivided into three subgroups of 10 t
... Show MoreKnowledge of permeability is critical for developing an effective reservoir description. Permeability data may be calculated from well tests, cores and logs. Normally, using well log data to derive estimates of permeability is the lowest cost method. This paper will focus on the evaluation of formation permeability in un-cored intervals for Abughirab field/Asmari reservoir in Iraq from core and well log data. Hydraulic flow unit (HFU) concept is strongly related to the flow zone indicator (FZI) which is a function of the reservoir quality index (RQI). Both measures are based on porosity and permeability of cores. It is assumed that samples with similar FZI values belong to the same HFU. A generated method is also used to calculate permea
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