In this study, graded Ni-P coatings were deposited on copper substrates by electroless plating method. The surface morphology and cross-section observations were made using scanning electron microscopy and optical microscopy. Degree of crystallinity was determined using X-ray diffraction (XRD). Results showed that the use of electroless Ni-P coatings with gradual change of phosphorus content led to an increase in surface smoothness and the formation of more compact nodules. The XRD patterns indicated that by heat treating, the amorphous phase of the high phosphorus layer was changed to crystalline phases, such as Ni, Ni 2 P and Ni 3 P. The graded Ni-P coatings had high wear resistance, and the coatings with the sequence of low P/medium P/high P layers from the substrate to the surface had the best wear resistance.

In this study, the functionally graded Ni-P coatings with low phosphorus top most layers were deposited on the copper substrates by the electroless plating process. The surface morphology and cross-section observations were made by using scanning electron microscopy and optical microscopy. The results showed that electroless deposition of the Ni-P coatings with gradual change of phosphorus content led to a crack-free compact nodular morphology. Also, by using the graded Ni-P coatings, the wear and corrosion resistance were improved. The multilayer coating with the sequence of Ni-high P/Ni-medium P/Ni-low P layers from the substrate to the top surface exhibited the best wear and corrosion resistance.

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As oil production continues, reservoir pressure decreases and oil production rate may not be as high as the plateau production rate. Once any sign of reduction in oil production rate has been observed, improved oil recovery (IOR) techniques are considered to aid the production. However, IOR methods could be accomplished from the beginning of oil production. Among different IOR methods, implementing artificial lift systems is one of the main options especially in brown fields. Artificial lift methods are categorized into pump-lift methods and gas-lift methods. In this study, screening process has been performed to find feasible artificial lift methods. During the screening process, different aspects of reservoir, well and fluid behavior have been studied to find the feasible options and it has been concluded that only ESP and gas lift could be implemented in this particular field. Both of these methods have been studied by simulating an integrated model including the reservoir and all of the candidate wells. So, impact of any variation in reservoir or well properties has been captured during the next 10 years. Three scenarios have been defined to predict the field performance by natural depletion, installing electrical submersible pumps and implementing gas lift system. Although an option might be selected as the best method for the present time, a long term evaluation is able to change the selected method. Integrated modeling the whole system of reservoir and wells provides a better understanding of the impact of different factors on performance of each scenario in long time. By performing a number of sensitivity analysis tests, it has been observed that increasing the water-cut may affect noticeably the performance of lifting systems. So, the pressure and water-cut of the reservoir and wells have been predicted during the next decade. It has been shown that using gas-lift method in the mentioned field has the highest oil recovery factor and the cumulative oil production during the next 10 years is more than 134 MMSTB. The ESP pumping system could lift almost 112 MMSTB oil during 10 years, while the natural depletion system has the lowest recovery and only 13 MMSTB oil could be produced during the same period.

In this study, the Ni-P/H-Cr coating from substrate to surface was deposited on copper by electroless plating (Ni-P) and electrodeposition (H-Cr). The surface morphology and crosssection observations were analysed using scanning electron microscopy and optical microscopy. The results showed that the use of Ni-P layer as an undercoat before H-Cr coating the surface morphology has changed from a non-smooth state to a smooth state. In addition, the microcracks on the surface layer of H-Cr can be reduced. The loss of mass diagram and the worn surfaces indicated that using an Ni-P layer underneath the H-Cr layer increased the wear resistance.

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