The Study Of Compatibility And The Selection Of Scale Inhibitor In The Zhaike-danba Field In Yanchang Oilfield

The well and water-oil gathering system in Zhaike-danba fieild of Xiqu oil puduction plant in Yanchang oilfield has a seriously scaling. The corrosion, perforation and blocking of pipeline caused by scaling will bring big problem to oilfield. As the Zhaike-danba fieild has many layers, it needs to satisfy the scal inhibiton during the waterflooding development, it will be a big problem.This subject through the research of domestic and international oil and gas wells and oil and water gathering and transportation pipelines on the scaling, scale, scale of data, to clarify a few common mechanism of oilfield scaling, the scale inhibition mechanism, as well as commonly used at home and abroadscale inhibitor type. Field scaling research, we extend the oilfield Walled eight blocks of oil and gas wells and oil and water gathering pipelines and oil field produced water, water-based and water quality analysis, and at the same time stable on the electrochemical ion technology to extend the oilfield Western oil production plant application of the sewage treatment station was introduced.The subject of the Village Branch of eight blocks of15sampling points were sampled, the water sample test results show that:Yan’an Formation water and the Luohe water well water rich of SO42-ion, to extend the group formation water containeddirt cations Ca2+, Mg2+,Ba2+, Sr2+content higher Yanchang formation water and the Yan’an Formation water or Luohe water well water mixed easily lead to the occurrence of fouling. In order to more accurately predict the formation of the different layers of water mixed solution fouling tendency and scaling trends change, we used the now more common Scalchem scale chemical analysis software on the situation in the different layers of the formation water mixed scaling trend forecasts, the application of the software to predict the fouling tendency of the water bodies in each layer, but also to predict the amount of injected water and formation water in accordance with different mixing ratio in the different conditions of temperature and pressure scaling and scaling trend changes. The results showed that Scalchem scale analysis of the chemical analysis of software:the injection water, the Luohe water wells, Yanchang formation water scaling and scaling trend of relatively small and will not affect the normal production due to fouling and extend group3,4+5of scaling the amount of long6formation water and fouling trend was relatively large, severe scaling. Inject a mixture of water and formation water into the main product to BaSO4, followed by SrSO4. only part of the injected mixture of water and formation water will generate a small amount of CaCO3and SrCO3dirt. Which:the mixing of injected water with4+5of formation water compatibility of the worst, the largest amount of its scale in the scaling, the scaling trend is most obvious.When the environmental temperature and pressure are gradually increased, the amount of scaling and the scaling trend of BaSO4has dirt is gradually reduced, SrSO4scale solution the amount of fouling and scaling trend with increasing temperature is reduced, increased with increasing pressure, elevated temperature and pressure in the environment at the same time, the type of dirt generated in the solution depends on the temperature and pressure which factors play a leading role.For serious fouling of formation water:this topic to join ANTISCALANT the prevention of scale in generation, to extend the oilfield Walled eight blocks in the development process in the injection of scaling product is the BaSO4dirt and SrSO4scale, in addition there will be a small amount of CaCO3scale and SrCO3dirt generated. The above scale in the type of the subject mainly from better scale inhibition effects of polymer scale inhibitors, and organic phosphonic acid scale inhibitor screening. First in the high-temperature atmospheric static conditions were screened,13kinds of scale inhibitors, scale effects are less than ideal when these scale inhibitors used alone. Late by between the scale inhibitor compound and then further screening and screening experimental results show that:when the environmental temperature of70℃, TH-607B and HEDP in accordance with a scale inhibitor formulations in the compound:a mixed, when the amount of scale inhibitor mixture30ppm, scale inhibitor Ba2+ions and Sr2+ion inhibition rate in about85%, and good scale inhibition effects.Ultimately selected by the laboratory formulation in oil field applications, the comparative year-on-year quarterly oil production wells and ground sets the input pipeline scaling investigated the effect of scale inhibitor in the field of application. Wells producing oil ring of the first quarter of2011than in the first quarter of2010, a5.7%increase in the surface gathering pipelines scaling has also been a marked improvement, only occur in parts of some of the pipeline, there is a slight scaling other lots of the pipeline without fouling occurred. This shows that:the scale inhibitor compound is very effective scaling problem can be solved to extend the oilfield Walled eight blocks.