Research On Scaling Mechanism Of Material In Water And Oil System In Oil Field

There are widespread scaling problems in production of oil. Considering from a single chemical analysis, at present the research of the mechanism shows slow response to the scaling formation, scales were still formed on the surface after long time, the property of anti-scaling was poor. From the material point, the property of anti-scaling was better.The hanging filter scaling experiment was done to study the anti-scaling property of the different materials in different media. The six cases of scaling on carbon steel, stainless steel, ceramics, paints, rubber coatings were researched under the three medium of ASP system, the sewage and water flooding in oil production. The materials surface and scale on the surface were analyzed and represented by SEM and EDS after scaling experiment. The composition of scale was analyzed. The scale deposit was obtained by way of weighting. The wetting angle was measured by the modified style-microscope to judge the wettability of materials. The results provide the data and image materials for the fouling prevention and mitigation in the realistic production.The results show that the average fouling mass on different materials was calculated according to the chemical compositions of solid materials. The SFE was influenced directly by the chemical composition of the solid materials and the scale deposit increased basically with the increasing of SFE. In the conditions of alkaline-surfactant-polymer (ASP) flooding oil recovery, the components of the scale contained corrosives and deposits on the surface of carbon steel, and the corrosion aggravated scaling. The main component of the rust was Fe3O4 and silicon oxide scale grows sequent on the iron oxide in rules shape. The SFE of Anti-scaling of Modified Fluorine Rubber is lower than that of HNBR and the performance of anti-scaling of Modified Fluorine Rubber is better.The main scale deposit was silicon oxide scale in ASP flooding system and that in was CaCO3 in sewage of oilfield. The weight of fouling material increased with the velocities of flow when the velocities of flow was less than 1.0m/s in (ASP) flooding produced fluid. The weight of fouling material achieves the highest value when the velocity of flow is 1.0m/s. The weight of fouling material decreased with the velocities of flow when the velocity of flow was greater than 1.0m/s. When other conditions were not changed, in the scaling was easier forming with the temperature increasing. The silicon fouling formed easily when the temperature was at the scope of 30℃~ 45℃.The scaling in ASP flooding produced fluid was different from that of one in injected fluid; the structure of scaling layer was not the same. The corrosion effected in fouling materials generating on pipeline equipment of the injected station. At the initial of scaling a large number of scrap-iron, sand and magnesium formed into core-scale diversion in solution first attached the surface, with the passage of time, calcium fouling gradually generated as a nucleation on that basis. Silicate scale formed on the basis of carbonate scale and accounted on the main part in produced liquid.The wettability effect of surface has a significant difference of the same liquid medium at different solid materials. The contact angle of ceramic materials was largest, the wettability effect was the worst and scaling did not easily adhere to ceramic materials. The contact angle of carbon steel was smallest; scaling did not easily adhere to carbon steel. Scale structures grew on the solid materials after induction period. First layer of sediments was absorbed on the surface of materials, a layer of the "conditions membrane" suited for the growth of fouling material was formed, then fouling materials grew on this layer of membrane.