Simulation of Cathodic Protection System Using Matlab

WIT Transactions on Engineering Sciences, 2009

Computational modelling of cathodic protection (CP) systems involving thin multi-layer media represents a real challenge in terms of accuracy and efficiency required in the numerical calculation. In the case of CP for transmission pipelines, these long metallic structures are usually buried a distance H (approximately a metre or so) below ground level and extend horizontally typically more than ten thousand times H. A number of impressed current anode beds are distributed along the pipeline, providing protection against corrosion of the structure. In addition, the vertically stratified nature of the soil needs to be considered in the model, in order to obtain more accurate representation of the environment. This is particularly relevant when considering the effect of different types of rocks, soil porosity, or water saturation, at different depths. This type of scenario requires three dimensional modelling involving a thin multi layered electrolyte, with a typical aspect ratio (lateral extension to thickness) of the order 1E4 to 1E6. The paper presents an efficient and accurate computational approach based on the Boundary Element Method for simulating the level of protection against corrosion of the pipeline as well as current densities and electric potential in different points of the soil. The resulting modelling approach is then applied to assessing real case scenarios. The simulation approach considers the non linear electrode kinetics on the metal surfaces in the form of polarisation data and also the internal resistance of the pipeline and other electrical connections involved in the CP system. Example applications are presented showing how the model can be used to predict the "signatures" associated with different defect types in the pipe coating.

2015

Cathodic protection is an electrochemical technique used to prevent the corrosion phenomena for metallic underground materials and pipelines. It is essential because the external coating could be insufficient for corrosion protection. The real corrosion protection level of a structure, a pipeline for example, is usually evaluated through measures made in few points of the pipe, generally once a day. In this way, the protection level of the whole structure is unknown. Advanced cathodic protection simulation software are spreading in order to fill this gap, especially for application in the oil and gas industry. The aim of this study is to evaluate what kind of advantages can derive from the application of simulation software to model the cathodic protection level for natural gas distribution pipeline. A real case study has been conducted in order to examine the real potentiality of this instrument. The main evaluated aspects are about the improvement of the process control effectiven...

Spektra: Jurnal Fisika dan Aplikasinya

Research has been carried out to map and identify the potential for soil corrosion for the planning of cathodic gas pipeline protection systems. The research location is located in Cimanggis - Bitung, West Java, which is located at coordinates 6o19'00 "- 6o28'00" South Latitude and 106o43'00 "- 106o 55'30" East Longitude. Measurement of soil resistivity using the Wenner method that refers to ASTM G37, with variations in the distance of 0,75m, 1,50m, 2,50m and 6,00m with the number of measuring points as many as 185 points. Based on the results of data processing and soil resistivity interpretation seen that there are several locations that have low to extreme corrosion levels. Therefore, for these locations, technical planning and calculation for the protection of the pipeline to be installed is necessary.

Corrosion Prevention of Crude Oil Steel Pipelines In Swampy Soil Using Cathodic Protection Method, 2013

A long time exposure of steel pipes underground causes their surface to corrode. The increasing cost of tubular goods failures due to corrosion in the oil and gas industry has increased interest in and importance of corrosion problems and their solutions. Metal dissolution and sudden cracking of tubing and casings are mainly caused by the presence of carbon dioxide, hydrogen sulfide, oxygen, and water. The presence of larger volumes of water in aggressive environments intensifies the severity of corrosion, while oil tends to form a protective oily film on the metal surfaces. Corrosion of buried steel pipeline can adequately be controlled by catholic protection method. In this study steel materials were buried in a swampy soil and their corrosion rates compared after forty-nine days. Cathodic protection impressed current was applied to one of the steel materials. The circuit was connected with a zinc anode, a 12 volt DC power source with the aid of copper wires, and the soil acted as electrolyte. Corrosion rate of the metals were determined using weight loss method, prior to washing and oven drying. After twenty eight days, the weight loss for protected steel was small compared to weight loss for unprotected steel and zinc anode. The protected steel lost a total of 0.0lg after forty nine days. However, the unprotected steel and zinc anode lost a total of 0.17g and 11.04g respectively. This result suggests that the catholic protection was effective. Hence, further finding on the actual voltage range required for effective cathodic protection should be studied.

Journal of Petroleum Research and Studies, 2022

This study focused on the two systems of Cathodic Protection, CP, (temporary (Sacrificial Anodes, SACP) & permanent (Impressed Current, ICCP) that were used to protect West Qurna (Tuba-1) crude oil pipeline42 in / Basrah Oil Company, BOC, from corrosion challenges. Design Calculations for CP systems were achieved according to the standards of National Association of Corrosion Engineers, NACE. These calculations were simulated using Matlab –Simulink Software 2018. Then, the simulated design was converted to Graphical User Interface, GUI. This GUI allows the user to enter the design data & perform the calculation faster & more efficiently. Furthermore, GUI was converted into a dependent program by installing Matlab Runtime Installer which enables the execution of Matlab files on computer without installed version of Matlab. The results showed that there was matching between the calculations of CP design & the simulated design. SACP demonstrated that 4 Mg anodes are required to pro...

13th Selected Issues of Electrical Engineering and Electronics (WZEE), 2016

The presented paper describes the principles of cathodic protection (CP) of underground tanks using the sacrificial anode as well as method of calculation of the potential, current density and polarization distribution on all sides metallic tanks buried underground. Differential equations with boundary conditions are developed and next solved by FEM in 2D and 3D cases. The main goal of this publication is the computation of such distribution of the external protecting electrodes where protected structure will not corrode and next the calculations in 2D and 3D were compared. The article shows that it is sufficient to use 2D analysis for which the speed of equations solution is significantly larger than in 3D space.

Environmental Research Journal, 2012

Corrosion of metals has been known to be disastrous in industrial setup and even more so in the petroleum industry. Transportation of crude oil, gas and processed petroleum products takes place in pipes, most often steel pipes. Several methods have been used to combat the problem of buried pipeline corrosion among which is cathodic protection. Cathodic protection of a buried steel pipe using zinc anode and a 12 volt DC power source has been studied. The experiment was set up in the laboratory for 35days using moist soil sample from Niger Delta region of Nigeria and weight loss recorded every seven days. Results show that after twenty one days, the protected steel began to lose a very small amount of weight, compared to weight losses for unprotected steel and the anode. A total of 0.04g of the cathodically protected steel was lost after 35days compared to a loss of 0.43g for the unprotected steel. The experiment shows that 90.69% protection was achieved with cathodic protection method of corrosion control. The work demonstrates that buried steel pipes in Niger Delta region of Nigeria can be cathodically protected against failure with very small quantity of electricity. It is recommended that this study be carried out in a soil with high salinity, typical of the Atlantic Ocean shore of Niger Delta where several oil pipelines are laid.

International Journal of Power Electronics and Drive System (IJPEDS), 2020

In this part, the implementation of the Cathodic Protection (CP) station in a new position is done due to the analytical study of the part (I) [1]. Also, a PV fed self-adjusted DC-DC converter is designed and implemented for this purpose, and Aluminum anodes designed and manufactured for the sake of approving the proposed CP station operation. A field test shows enhanced results due to the National Association of Corrosion Engineering NACE standard. An edit has been made on the main empirical formula that is previously intended for the design of the same CP system. The proposed CP station is very flexible, more accurate, of lower cost, and needs little maintenance as compared with the already existing CP station.

2013

In this research, the effect of soil resistivity on the sacrificial cathodic protection of a pipeline steel of oil was studied. Sufficient sacrificial cathodic protection could be obtained at various soil resistivty for different types of anodes. High current output (2.98, 2.38 and 8.33 Amps) of Zn, Al and Mg anodes respectively, are obtained at 25 ohms.cm soil resistivity. Simultaneous, for the same conditions, low numbers and large weights of anodes are required to satisfy protection.

1999

A ®nite element numerical model was set up to calculate the secondary distribution of potential and current density at the surface of a buried tank. The steel gas tank of interest was protected by both coating and two sacri®cial anodes (magnesium alloy or zinc). The dispersion of actual soil properties was taken into account by use of three typical soils. The comparison of two dimensional and three-dimensional models shows that the 2D model is obviously both convenient and time saving. The numerical model allows the calculation of the cathodic protection current and of the local potential in every point of the tank. The model intends to compare the relative in¯uence of coating quality, electric conductivity of soil and position, size and type of the sacri®cial anodes (magnesium or zinc). Soil conductivity and coating porosity appear as the two most in¯uential parameters. This model justi®es the interest of the tank experimental potential and current measurements.