Material Selection And Adaptability Evaluation Of Non-metallic Degreaser In A Combined Station Of An Oil Field

The shell and internal components of the degreaser of an oil field combined station are made of No.20 steel,Q235-B steel and 304 stainless steel.Working in the sewage environment with high salinity and high corrosivity,serious corrosion has occurred and there are potential safety hazards.Non metallic materials have better corrosion resistance than metallic materials,but in the harsh oilfield environment,aging failure will also occur,affecting the service life of the equipment.Therefore,carrying out material selection and adaptability evaluation of non-metallic degreaser has certain field application value.Investigate the working parameters and environment of the oil field degreaser,the application of non-metallic materials and equipment,and the national standards and specifications for the use of non-metallic materials in the oil field,and preliminarily select four kinds of non-metallic materials suitable for the on-site environment of the degreaser: FRP,PP,PA12 and PVDF.Aiming at the four factors affecting the performance of non-metallic materials: temperature,salinity,pressure and ultraviolet light,simulate the working environment of the degreaser,carry out soaking experiment and illumination experiment,and change the physical,chemical and mechanical properties of the materials.Analyze the changes of physical,chemical and mechanical properties of non-metallic materials through electron microscope scanning(SEM),Fourier infrared(IR),thermogravimetric and differential thermal(TG-DSC),hardness and impact properties,FRP and PVDF materials with good overall performance are selected as the structural materials of the degreaser.ABAQUS finite element software is used to analyze the stress and strain laws of FRP and PVDF degreasers,which meet the actual requirements on site.Using tensile test,artificial accelerated aging test and Arrhenius empirical equation,the life prediction model of FRP and PVDF material degreaser is established.It is calculated that the service life of FRP and PVDF materials is 25 years and 22 years respectively under field conditions,which meets the field requirements.The production and operation cost of FRP and PVDF material degreaser is calculated by the net present value method.The net present value is greater than 0,and the net present value of FRP degreaser is greater than PVDF.The structure and material of FRP degreaser are optimized.