In the development of an accurate modeling technique for the design of an efficient machining process, manufacturers must be able to identify the most suitable technique capable of producing a fast and accurate performance. This study evaluates the performance of the Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) models in predicting the machining responses (metal removal rate and tool wear) in an AIS steel turning operation. With data generated from carefully designed machining experimentation, the adequacies of the ANN and ANFIS techniques in modeling and predicting the responses were carefully analyzed and compared. Both techniques displayed excellent abilities in predicting the responses of the machining process. However, a comparison of both techniques indicates that ANN is relatively superior to the ANFIS techniques, considering the accuracy of its results in terms of the prediction errors obtained for the ANN and ANFIS of 6.1% and 11.5% for the MRR and 4.1% and 7.2% for the Tool wear respectively. The coefficient of correlation (R 2 ) obtained from the analysis further confirms the preference of the ANN with a maximum value of 92.1% recorded using the ANN compared to that of the ANFIS of 73%. The experiment further reveals that the performance of the ANN technique can yield the most ideal results when the right parameters are employed.

All steel pipelines used in hydrocarbon transportation are susceptible to either electrolytic or galvanic corrosion attack which deteriorate with time leading to failure even before end of design life. Consequences of corrosion attack and eventual failure of pipelines within oil and gas industry has been classified into economic, health, safety and environmental impacts. The present study considers detailed review of practical field corrosion control and monitoring mechanisms necessary to preserve, extend service life of pipelines and reduce corrosion impacts. The corrosion controls are various preventive strategies considered during construction and prior to pipelines' commissioning which include design, material selection, protective coating, chemical treatment and cathodic protection system. But the corrosion monitoring strategy is aimed at establishing condition of pipelines and environmental variables that may accelerate corrosion process and this includes potential survey, bacteria count, corrosion coupons and intelligent pigging. The identified corrosion control and monitoring techniques are not governed by any industry code and standard but has been generally accepted as best practice within the oil and gas industry as ways of combating corrosion and evaluating pipelines condition. Therefore, effective implementation of the identified corrosion control and monitoring strategies would limit corrosion attack and guide pipelines' operators to make informed decision and timely respond to corrosion threat before failures.

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Several inadequate designs of cathodically polarized offshore and onshore pipelines have been reported in Nigeria owing to design complexity and application of the cathodic protection system. The present study focused on critical and detailed approach in impressed current and sacrificial anode design calculation methodologies for 0.5m diameter and 100000m length of X65 steel pipeline in onshore and 1.2m diameter and 120000m length of X42 steel pipeline in offshore of Niger Delta region of Nigeria. The impressed current design calculation showed 2592150mA of current demand and voltage of 1127585mV required to adequately protect the X65 pipeline with external surface area of 86405m 2 . The current and voltage requirements were achievable by installing six transformer rectifiers with minimum direct current output of 500amperes and direct voltage output of 200volts. But the sacrificial anode design calculation indicated direct current output of 2262240mA was needed to marginally polarize the X42 pipeline with total external surface area of 226224m 2 . The computation further showed the current requirement was attainable with connection of 3620 anodes to set up a natural potential between sacrificial anode and pipeline.

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