Study On Influencing Factors And Scale Inhibition Effect Of Scale In A8 Area Of ​​Hujingshan Oilfield

With the development of petroleum and natural gas exploitation speeding up and more thorough research in water flooding, water content in produced fluid gets higher, and the effect of oilfield water scaling problems on the normal production of oilfield gets more obvious.Because of the incoMPatibility between injected and formation water and the disequilibrium of chemical composition caused by alteration of temperature, pressure, pH value during flowing, scaling happens in the reservoir, wellbore oil water wells, pipe-lines and equipment. This paper exhaustively analyses the precipitating factors of calcium sulfate, barium sulfate, strontium sulfate, calcium carbonate and magnesium carbonate from the point of view of inorganic scale solubility in water, illustrating the scaling mechanism of thermodynamics, crystallization kinetics, fluid dynamics and chemical in-hibition as well as researching on scaling prediction technology.Based on the theory research of this paper, A8Hu Jianshan oilfield as the research object, the experimental study of scaling factors and effects of the scale inhibition will be launched. Fluid analysis of A8area of Hu Jianshan as basic data, scaling prediction soft-ware is applied to study the regular pattern of variation of scaling type and quantity of formation, wellbore and ground pipeline under the influence of different factors.Research is carried out according to the prediction result, which indicates the major formation scal-ing is formed with barium sulfate, strontium sulfate, and mixing ratio is the main factor affecting formation scaling with lighter influence of temperature, pressure. pH val-ue.Wellbore scaling primarily involves calcium carbonate.PH value is the main factor af-fecting the wellbore scaling with less effect of temperature and the least of pres-sure.Ground pipeline scaling is mainly composed by barium sulfate scale with greater ef-fect of PH value and the less of temperature and pressure.On the basis of major scaling types, optimization experiment of scale inhibitor study is launched.Result shows the most effective scale inhibitor for formation scale is inhibitor TH-607B, ZX-101with scale inhibition rate of more than75%.The most effective scale inhibitor for wellbore scale is inhibitor DTPMP with scale inhibition rate of around80%.The most effective scale inhibitor for ground pipeline is inhibitor TH-1with inhibi-tion rate of93.2%.Scale inhibitor evaluation research indicates with the increasing con-centration of scale inhibitor, inhibition rate increases then decreases.Every inhibitor has an optimum concentration value due to the tolerance effects, as TH-607B and ZX-101for140mg/L, DTPMP for80mg/L, TH-1for100mg/L.Temperature has little effect on inhab-itation result with favorable performance of thermal stability. With the increase of tem-perature, the inhibition rate increases first and then decreases.the temperature between45℃to55℃can play the best inhibition effect.Pressure has little effect on the per-formance of4types of inhibitors.Too low or too high PH value has evident effects on scale result.PH value in the6.5-7.5range has the best inhibition effect.In results, the op-timal inhibitor and the best amount applied for the formation, wellbore, and ground pine line of A8area of Hu Jianshan is acquired which provides a basis for chemical scaling of the very area.