The Study Of High Calcium Crude Decalcification Agent And Process

With the heavier and inferior of crude oil and the application of tertiary oil recovery technology,the calcium content in crude oil become higher which is harmful for the deep processing of oils.So crude desalination problem have become a hot topic.Among many desalination technologys,the chelating decalcification have been widely used because it can directly combine with the original electric desalting technology so that the investment was small and operation easy.Decalcification agent is the key of chelating decalcification process,and the formula of which can direct influence the decalcification rate.Therefore,developing efficient,green and economic decalcification agent is of great significance for improving heavy oil processing of our country.The crude oil researched in this paper was high calcium oil.The basic properties,four components,the distribution and composition of calcium compounds over crude oil were analyzed.In the decalcification agent formula screening process,we tested eight kinds of different single calcium and selected four better to carry out further experiments firstly.Then,on the basis of these four single decalcification agent,we prepared a+b type and a+b+c type complex decalcification agent.Through series of tests and analysis,we found that A+AA/AMPS+B complex decalcification agent in the mass ratio of 1:2:1 owned the optimal decalcification activity.Combine with the evaluation results,we speculated the possibly effective functional groups and which synergistic effect mechanism of decalcification process.This paper studied the decalcification agent dosage,water injection rate,reaction temperature and reaction time to the decalcification activity.The optimal reaction parameters as follow:decalcification agent dosage 5000?g/g;water injection rate 15 wt.%;reaction temperature 95°C and reaction time 10 min.Finally,we investigated the decalcification agent,demulsifie and water distribution in the whole 1^st,2^nd steps decalcification-3^rd step desalination technology.The optimal distribution as following:decalcification agent 1:1:0;demulsifie 2:1:1;water 2:2:1.With the decalcification treatment of high calcium content crude oil by chelating desalination technology,the density and viscosity reduced slightly while the calcium content droped suddenly.The calcium content of crude oil attenuated by methylbenzene and without attenuation reduced to 18.72?g/g and 59.24?g/g,respectively.In the simulated field,the decalcification rate can reach 96.37%,meanwhile,the Fe,Ni content decreaced as V content stably and the acid value increased.The Ca and Fe content,hardness and COD value of decalcification sewage increased while PH decreased.