环保型钻井—压裂通用水基工作液研究

Environment friendly water-based working fluid for universal drilling and fracturing

为了减少钻井和压裂作业时油田化学工作液的总耗材量和总排放量,进行了钻井—压裂通用水基基础工作液的研究。选择聚合糖衍生物SJ作为通用工作液的主剂,参照SY/T 5621—1993《钻井液测试程序》评价了通用水基工作液作为钻井液的性能。实验结果表明:钻井液流变性、滤失性和抑制性满足油田应用要求,而且抗温能力良好,能够抵抗2800 mg/L的Ca2+、1900 mg/L的Mg2+和2500 mg/L的K+污染。探索了钻井液转化成压裂液的一体化工艺,参照SY/T 5107—2005《水基压裂液性能评价方法》评价转化后的压裂液性能。实验结果表明:以SJ为主剂的水基钻井液可以向压裂液转化,实现钻井—压裂水基基础工作液通用的目标,转化后的压裂液抗温极限为83.3℃,流变性、滤失性、携砂性、抗剪切性、破胶性、配伍性和破胶后残渣含量均可以满足油田应用要求。

Fracturing is a necessary measurement to increase production after drilling and completion well in most low permeability oil field.In order to decrease the total amount of supplies and total emissions of oilfield chemical working fluid in drilling and fracturing treatment,water-based drilling-fracturing universal working fluid was researched.Heter-polysaccharose SJ was chosen as main fluid of current driving fluid,and the performance of drilling-fracturing water-based fluid was evaluated as drilling fluid according to testing procedure of drilling fluid SY/T 5621—1993.The laboratory experiment shows that the rheology behavior,filtration and inhibitive abil-ity could meet the requirement of Changqing Oilfield application.It have well ability of resisting temperature and also could resist the pollution of 2800 mg/L Ca2＋,1900 mg/L Mg2＋ and 2500 mg/L K＋.Indoor integration process of drilling fluid changing into fracturing fluid was explored.According to SY/T 5107—2005,the property of fracturing fluid was evaluated after it has been transformed.Labora-tory result shows that SJ could transform to fracturing fluid which was used as main fluid in water-based drilling fluid,and could achieve the object of drilling-fracturing current driving fluid.the maximum combat temperature was up to 83.3 ℃,after been transformed,and all the rheology,filtration,the ability of taking sand,shear resistance,breaking property,compatibility and the content of caput mortem after gelout could meet the requirement of field application in Changqing Oilfield.