Research On Scaling And Corrosion Prediction Model Of Water Injection Pipeline

The reinjection of produced water has now become an important means of water injection in various oil and gas fields to increase production,which not only saves costs,but also reduces pollution.At the same time,the development of re-injection will also lead to serious blockage and corrosion of the water injection pipeline,causing great inconvenience to the maintenance of the pipeline.Therefore,in order to facilitate the maintenance of the water injection pipeline,it is necessary to make a realistic prediction of the scale and corrosion in the pipeline.In order to solve this problem,this paper analyzes the scaling and corrosion factors by investigating the water quality and corrosion coupon test,and determines that Ca CO₃,Ca SO₄,Ba SO₄and dissolved oxygen that cause scaling and corrosion of water injection pipelines are the research objects.The scaling mechanism and the process mechanism of uniform corrosion caused by dissolved oxygen were then established based on the deposition and removal model of scale,combined with crystallization reaction kinetics and Oddo-Tomson equation to establish a scaling thickness calculation model;The mechanism model for rate calculation,and considering the hindering effect of fouling porous media layer on corrosion,a one-dimensional dynamic mass transfer model is constructed to correlate fouling and corrosion;the calculation of dynamic parameters such as pressure,temperature,physical properties,p H,etc.in the water injection process is established Model.Using the actual water injection pipeline as the carrier to establish a spatiotemporal model,using the numerical calculation method of iteration in time and recursion in space,the coupled calculation of the model is realized through MATLAB programming,and the predicted value is compared with the actual data.The average relative errors of the model predictions are 4.20%and 5.64%,respectively,indicating the feasibility of the model.Finally,App Designer is used to compile the water injection pipeline scaling and corrosion prediction software,which realizes the visualization of the model and forms an industrial platform for predicting the scaling thickness,corrosion depth and dynamic injection pressure changes of water injection pipelines in oil and gas fields under different working conditions.Provide meaningful guidance on water injection process improvements as well as pipeline maintenance.