酒东油田注水系统结垢分析及应对措施

Scaling Mechanism and Countermeasures of Water Injection System in Jiudong Oilfield

为了解决酒东油田注水系统结垢严重的问题,分析了酒东油田注水(K1g1与K1g3油藏采出水混合)结垢原因,评价了7种阻垢剂对碳酸钙垢和硫酸钙垢阻垢效果,通过扫描电镜分析了结垢晶体的形貌。研究结果表明:酒东油田注水结垢类型为碳酸钙,含少量硫酸钙垢。聚天冬氨酸(PASP)对注入水的阻垢效果最好。PASP的分子结构中含有的羧酸阴离子与Ca^(2+)形成溶于水的螯合分子,吸附在结晶体表面的PASP降低了分子间的作用力,破坏了晶体结构,使晶体形态发生畸变,有效阻止晶体的生成。在酒东油田注入水中加入PASP可较好地解决采出水回注的结垢问题。图5表5参11.

In order to solve the serious scaling problem of water injection system in Jiudong oilfield,the scaling cause of injection water(K1G1 mixed with produced water from K1G3 reservoir)in Jiudong Oilfield was studied,the effect of 7 kinds of scale inhibitors on calcium carbonate scale and calcium sulfate scale was evaluated,and the crystal structure of scale was observed by scanning electron microscopy(SEM).The results showed that the scaling type of the injection water was calcium carbonate,with a small amount of calcium sulfate scale.The scale inhibition effect of polyaspartic acid(PASP)was the best.it was found that the carboxylic acid anion contained in the molecular structure of PASP could react with Ca^(2+)to form soluble chelating molecules in water,and PASP adsorbed on the surface of the crystal,which reduced the intermolecular force and destroyed the crystal structure,as a result,the crystal morphology was aberrated and the formation of crystals was effectively prevented.By adding PASP into the injected water in Jiudong Oilfield,the scaling problem of produced water reinjection could be solved.