Researches About The Sewage With Polymer And Technology On Compounding Polymer Solution By Sewage On The Ground

As the constant expansion of polymer-flooding industrial production scale, the water with low salinity in the oilfield is in supply shortage. Many disadvantages are becoming more and more serious which are caused by simply counting on the clear water compounding and diluting the polymer solution. On one side, it wastes much clear water; on the other side, much sewage is drained out so as to pollute the environment. Nowadays, in the oilfield, the method for injection and allocation rate that compounding the mother solution by clear water and diluting the polymer solution by sewage is widely used. However, this method causes the shortage of sewage so that new sewage disposal stations are needed to build which costs much money. Therefore, on the base of a general survey about test zones, the essay selects water-injection stations and polymer-injection stations to take a sample from sewage and sewage with polymer, and make experiments about the technology of compounding the polymer solution by sewage. Moreover, it makes researches about the feasibility that compounding polymer solution by sewage on the ground and the factors influencing the viscosity. To improve the water quality by application of germicide and oxygen exposure, the method that compounding polymer solution by sewage can be demonstrated to realize in the field test. Meanwhile, if it is feasible to compound the polymer solution by sewage on the ground, much clear water can be saved to achieve great economic and social benefits.In the experiments, it can be discovered that the water quality of sewage and sewage with polymer can reach the standard, and the effects of the germicide and oxygen exposure technology are more ideal in different test periods. The results reveal that under the condition of current oxygen exposure technology, the exposure amount suitable to the sewage and sewage with polymer is 4～5mg/L. For North 16 Sewage Disposal Station, it will add germicide with a parameter of 150kg/d,2d/times (matched 30 mg/L) to guarantee that the amount of all kinds of viruses can be controlled in 1~2 order of magnitude. During the period of compounding with sewage, the monitoring data of single wellhead is 90～130mPa.S, the average viscosity value of 10 experimental wells is 107.8mPa.s; while during the period of compounding with sewage with polymer, the average viscosity value of 10 experimental wells also reaches 108.9mPa.s. It is completely feasible to compounding with the sewage with polymer. Under the same amount of dry powder, its wellhead viscosity value can be equal to that of only sewage so as to satisfy the demands for development plans. There are some factors to influence the viscosity lost of sewage with polymer on the ground, including salinity, thallophytes and oxygen contents. The viscosity of compounding with raw water is one-third less than that of clear water system and its viscosity stability is poor. The amount of polymer to different molecular weights will be added 600~1000 mg/L to reach the equal viscosity features of clear water system.