The Research Of Produced Water Re-injection Treatment Technology In DingBian Oil Blocks

Now days, with the development of oil and gas filed in Yan’an Oil and Gas CO., almost all developed blocks exist in varying degrees of multi-storey development. Because of produced water in different layers has different composition, reaction between ions will result in fouling after produced water mixed, plugging wells and pipelines and dropping oil production. In order to solve the produced water treatment, re-injection and other issues, and provide technical support for the subsequent construction of sewage treatment, this paper carried out the research of produced water re-injection treatment technology in Ding Bian oil blocks.First of all, in order to understand the current situation of sewage treatment in Yan Chang Oil Field, conducting a investigation to the main process and health of the treatment of produced water re-injection in Xing Zichuan oil blocks. Secondly, According to the characteristics of the waste-water in Ding Bian oil blocks, in order to improve the effect of multi-layer hybrid re-injection sewage treatment in Ding Bian oil blocks and prevent corrosion and fouling, through the pharmaceutical research of the mixed Chang-6 and Chang-9 layers hybrid produced water, realization the technology integration of multilayer mixed sewage treatment, corrosion, scaling for Ding Bian oil blocks. The results show that the suspended solids content of Chang-6 layer produced water is 23.08mg/L, the oil content is 0.8333mg/L, the total iron content is 0.28mg/L, salinity is 26005.004mg/L; the suspended solids content of Chang-9 layer produced water is 60.14mg/L, the oil content is 75.833mg/L, the total iron content is 13.17mg/L, salinity is 7049.079mg/L. Two waters are mixed in the proportion of 1:3; p H is 7.5; oxidizer is Na Cl O, dosage is 10mg/L, working time is 30min; inorganic flocculants is PAC, dosage is 90mg/L; organic flocculants is PAM, dosage is 0.6mg/L;using the PAC first and then the PAM, the interval between PAC and PAM used is 30 s. With all the conditions above,the suspended solids content and the oil content can be dropped down to 10.0mg/L. What’s more, because of the multi-layer mixed water likely to scaling, this paper use the gravimetric method to explore a new equipment for solving the problem. The results show that under the situation of filling material is sponge, velocity of flow is 0.03m/s, temperature is 40℃, cycle time is 15 h, scaling of the produced water has dropped from 146.46mg/L to 19.504mg/L.