This paper studies the mechanism of formation of the deposit layer by (ESD) electro-spark deposition process. Inconel 738 substrates are coated with a deposited layer of NI6625 (Inconel 625). Selections of these two alloys have been done because they had wide applications and importance in the industry especially in gas turban blades in inland stations and in aircraft engines. ESD is suggested because it has a low input heat process which eliminates the effect of HAZ in these Ni-superfluous due to their sustainability to micro-cracks. The coating contains many deposited sub-layers coming from evaporated and melted micro-regions as a result of locally high heat generated by discharging a series of capacitors charged and discharged in a controlled manner between electrode and substrate material. The maximum deposition rates at the beginning of the process and decreases until been in a steady state condition due to the nature of the resultant morphology of the created surface

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Predication Corrosion rate is quantitative method by which the effectiveness of corrosion control and prevention techniques can be evaluated and provides the feedback to enable corrosion control and prevention methods to be optimized. In this paper, a novel Model to predict corrosion rate based on RBFNN was proposed. A model is produced from experimental work for one year and eighty four specimens were used through this work using anode with a high level of precision. Learning data was performed by using a 36 samples test with different Environment Resistivity (ER), Impressed Current (IC), Location of Anode (LA), Corrosion Current (CC) and Corrosion Rate (CR). The RBFNN model has five input nodes representing the (ER, IC, CC, LN, and SA), sixteen nodes at hidden layer and one output node representing corrosion rate (CR). Simulation test use 6 data samples taken from the experimental results to check the performance of the neural network on these data and shows the proposed model can be use successfully to predicate the corrosion rate.

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Petronas has successfully set a new milestone in the history of casing while drilling (CWD), pushing the limit with 20 inch to 1002m MD, deepest in the world to date in a recent Malay Basin operation. Objective of this case study is to share the success story of CWD application in PETRONAS. CWD has come to a matured stage, widely practiced and become a normal practice particularly in Petronas Malaysia operation. This case study paper will focus on how the challenges turned to opportunities, and the overall assurance process leading to this achievement. Challenges, planning, engineering, execution, lessons learnt & potential future enhancements will be the main key highlights in this paper. Key objective of CWD utilization in this project are for drilling optimization and prevention of potential NPT contributed by wellbore stability. Offset wells' wellbore condition and issues has become the key reference to kick start the process, followed by objective prioritization, OCTG screening & selection, operating parameters, casing drilling fluid selection which lead to a successful CWD operation. Pre-planning and equipment preparation for this Level 2 CWD had been engineered to avoid any potential problems due to equipment malfunctions. This paper also analyzed potential future improvement which would extract more benefit from this technology. Integrated risks assessments and HSE considerations have been the highest priority, which cover all aspects in offshore CWD operation including well control and operational optimizations. CWD allows drilling the borehole and cased off the wellbore in a single trip. Total time for an interval was reduced by eliminating the time for running casing and mitigating downhole problems with borehole instability. The section was drilled with an average ROP of 30 m/hr. In general, the CWD operation for this project saved 1.5 days or USD 500k from the well cost as compared to conventional drilling and casing running operations. The drillable casing drill shoe was drilled out with a PDC bit, eliminating dedicated trip. This has directly reduced the cost and improved operational efficiency for the project. Surface section losses has been identified as one of the potential risks based on offset wells. The clay smearing effect had assisted in plastering the potential losses zone which lead to smooth casing drilling and running operation. Other benefit was elimination of HSE exposure from conventional methods, such as manual handling of casing and its running equipment. No recordable accidents/incidents during the operation. Major focus and input on this paper will be pivoted mainly on Well C which has been successfully drilled and cased at 1002m MD. However relevant input from Well A and Well B will also be included as reference and explanation, in the effort to seamlessly show the journey from initial stage until current stage of confidence in implementations. Comprehensive analysis and detail engineering planning, together with a full geological & subsurface review has increased PETRONAS confidence level to continue pushing the envelope further; exploiting the benefit of CWD. Relevant best practices, analysis, casing drilling job preparation & procedures will be beneficial for PETRONAS CWD operation in Malay Basin.