Steel catenary risers (SCR), though an appropriate and cost effective tool for deepwater development, are fraught with difficult fatigue challenges derived from loads due to the actions of wind, wave and current. In this study, a model SCR-AB with end-A attached to floating production, storage and offloading vessels (FPSO) and end-B anchored to the seabed was created using OrcaFlex © finite element software. Also attached to this model is a 10 4 kg 6D buoy of 6 m height and volume 20 m³, which was fixed to the SCR at 900 m of the riser length. The various sections of the homogenous 2200 m long SCR pipe include 50 m flex joint section, 350 m strake length, 1300 m riser pipe length, and 500 m flowline section. Metrological ocean data, geotechnical data and SCR data were input into the model which was subjected to the Ochi-Hubble and Joint North Sea Wave Project (JONSWAP) wave spectra. Analyses to determine the influence of fatigue damage on the model was made using system simulation under both static and dynamic modes. The results for JONSWAP wave spectra showed the fatigue life of the SCR to be 1.8 years at the touchdown point (TDP) while that of Ochi-Hubble wave spectra showed a fatigue life of 13.6 years at SCR TDP, differing by a factor of 7.5. Furthermore, the S-N curves obtained from both wave spectra corroborated an inverse relationship between Stress values S and the number of stress cycles to failure N on a log-log scale.

The suitability of cutting fluids formulated from spent engine oil has been considered. In the formulation, recycled Spent Engine Oil was used as a base oil, liquid washing soap as emulsifier, phenol was applied as disinfectant while sulphur served as extreme pressure agent. Analysis and comparative assessment of the physical-chemical properties of samples of cutting fluid was conducted. From the performance analysis, the optimal sample has values such as flash point, 205.92 o C; pour point,-13.04 o C. Viscosity, at 40 o C gave an average value of 96.06cst. At 100 o C, have average value of 7.57cst. The sample has average pH value of 9.03. In corrosion grading, it rated non-corrosive. Furthermore, the effectiveness of the developed products was measured, among other parameters, through tool tip temperature, material removal rate and tool tip wear. Sample VII presented the least mean temperature of 32.5 o C. Sample III presented the minimum mean value of tool tip wear. Sample VII gave the best material removal rate of 5.68g/min. From the results obtained from the analysis, the developed spent engine oil based cutting fluid samples compared favourably with the conventional cutting oil, thus making them acceptable for machining application and can also be an economical choice for use in machining processes.

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This paper examines pipeline safety and develops a mathematical model for predicting illegal intrusion. The model idealizes a typical pipeline structure as a pipe-in-pipe double beam, consisting of the process pipe encased in a larger diameter outer carrier pipe resting on an elastic soil foundation. Intrusion is considered to consist of hammering and cutting activities on the casing pipe which transmits shock motion to the process pipe. From the solution feedback control algorithms have been proposed for designing surveillance instruments which assist in mitigating the problem of illegal intrusion for harvesting of crude oil. A point sensor was used to simulate the response to intrusive hammering action induced on the casing pipe in a 2 m segment of the process pipe in an example. Sensor was conFigureured to measure displacement response at intervals of 2 seconds at (0.00, 0.06, 0.12,..., 2.00) m sampling points. The displacements indicated within the model assumption of zero damping, were 4.62 x 10-4m and 4.24 x 10-4m at the left and right hand anchors. A deflection of around-2.67 x 10-4m was obtained at 0.94 m.

This devise addresses the inadequacies of providing a quick means of holding jobs of irregular shapes such as are encountered in small scale fabrication workshops. The conventional bench vise often does not provide the adequate grip for such shapes so that attachments in the form of V blocks are usually provided to enhance the grip before drilling operations are carried out. This versatile work holding device enables fabricators to perform drilling and other production operations on a work piece. This device produced from mild steel plates uses the toggle principle to provide rapid grip. Comparative tests on time span in the use of this device and the bench vice for job set up, production operation and then disassembly showed that time is gained with use of the device.