临兴致密砂岩气区块废弃钻井液固液分离实验研究

Experimental research on solid-liquid separation of waste drilling fluid from Linxing tight sandstone gas area

针对临兴致密砂岩气区块废弃钻井液,研究影响固液分离工艺的因素,开展pH值、絮凝剂类别和浓度等对于废弃钻井液脱水率的影响实验。结果表明,调节pH值至中性或弱酸性和加入絮凝剂条件下,通过离心分离废弃钻井液脱水率可达89.62%,比未加药处理效率提高55.2%。加酸和絮凝剂调质后离心的处理工艺适用于临兴致密砂岩气区块废弃钻井液处理。分离出的液相重复配制钻井液体系性能满足现场技术要求。

The influence factors in processing solid-liquid separation for the waste drilling fluid from Linxing tight sandstone gas area were studied.The pH value,kinds and concentration of the flocculants were investigated.The results indicated that after decreasing pH value of waste drilling fluid to neutral or weakly acidic and adding the flocculants, the water separation rate was 89.62 %,which enhanced 55.2 % than that before chemicals treatment.Therefore the centrifugal separation technology after adjusting the properties by means of adding acid and flocculants is applicative and feasible for treating the waste drilling fluid.The properties of drilling fluid employing the water separated from waste drilling fluid satisfy the technical requirement.