Research On Re-using Of Heavy Oil Sewage In Thermal Steam Generators

The crude oil production of Liaohe Oilfield is 14 million t/y and the rate of heavy oil sewage at present is up to 84100m3/d, making up 56.6% of the total sewage amount of Liaohe Oilfiled. Therefore, how to handle the huge amount of heavy oil sewage reasonably is a great challenge to Liaohe Sub-company economically and technically, which has affected and restricted the continual development of oilfield directly.Liaohe Oilfield has conducted a great deal of research and field application in standard discharging and re-using of heavy oil sewage in thermal steam generators, thus some sewage treatment facilities have been put into operation. Nevertheless, the quality and quantity of heavy oil sewage vary greatly, the densities of oil and sewage are quite close, emulsion is serious, plus irrational treating process and lack of efficient chemicals, substantial progress has not achieved in re-using heavy oil sewage. Furthermore, problems still exist in the aspects of technical-economical index and practical operations of sewage treatment equipments, such as prolonged process, low efficiency, low degree of automation and high operating expenses. Therefore it is of great significance for the continual development of Liaohe Oilfield to improve the technology of heavy oil sewage treatment.It has twenty or thirty years history to re-inject the heavy oil sewage into the thermal steam-generating generator at home and abroad, and a lot of research achievements have been reported in the literature with scores of processing methods presented. But there are scare research papers about how to treat heavy oil sewage to reach the discharge standard. So there is little experience for reference.The purpose of the research is to develop an easy, effective and practical heavy oil sewage processing method, considering the China's situation. The systematic research and analysis has been done by laboratory research, field pilot test (processing capacity of 1 m3), and field test (processing capacity of 10 m3), and a reasonable operatingprocess for the sewage injecting the generator has been established and the project design parameters have been determined. Through the research, the problem of the heavy oil sewage treatment can be solved to realize the re-use the heavy oil sewage. The following are the basic guide lines to do the research.a. By widely referring the heavy oil sewage treatment experiences home and abroad, ,new ideas are developed. At the same, in view of the complication and great variation of heavy oil sewage quality, a new and high effective treatment process is developed.b. Al kind of contradictions in treating the heavy oil sewage are tried to consider systematically and perspectively, and try to avoid the negative effect brought about by the new process.c. When we analyze the contradictions in treating the heavy oil sewage, we combine the oil removal part, suspending material removal part and SlOa removal part to solve the specific problems by taking one another's advantages and try to do the test repeatedly under the possible conditions.The study mainly covers the following aspects based upon the target and basic idea of the study:1. The study and application of high efficiency sewage purifying chemicals. Further improve the formulation of high efficiency sewage purifying chemicals in order to improve the disposal result. Incorporate oil interceptor and solution gas float devices with the sewage purifying chemicals.2. In the pilot test of sewage water disposal, slant oil interceptor and gas float are conducted. Oil bearing content and suspension can reach the incoming water index of the steam generator, with the disposal of 10m3/d.3. In the mid-test of oil removal in the sewage, slant oil interceptor and gas float disposal are used. Oil bearing content and suspension can meet the requirement for steam generator water incoming index with the disposal of 240 m3/d.4. In the mid-test of sewage going to the steam generator, dual filter and ion exc...