油气田产出水系统碳酸钙结垢预测

Prediction of CaCO_3 Scaling in Produced Water System in Oil and Gas Fields

结合热力学和动力学影响因素,综合考虑碳酸钙结垢的结晶、沉积和剥蚀过程,建立了油气田产出水系统中碳酸钙结垢的预测模型,运用编制的软件对某气田产出水井筒进行了碳酸钙结垢预测,选取靠近井口、井筒中部和井底的三个典型部位进行了室内模拟结垢实验和饱和指数法结垢趋势预测。结果表明,井筒结垢量随着井深增加而增大,在一定时间后达到垢物附着与脱落的动态平衡状态,软件模型预测法与实验测试结垢趋势相吻合,能够较好地预测油气田产出水的碳酸钙结垢,对产出水系统防垢除垢具有指导意义。

Combining the thermodynamic with dynamic factors,a calcium carbonate scaling prediction model of produced water system in oil and gas field was built under the joint action of crystallization,deposition and denudation. With the prediction software developed,the CaCO3 scaling in a gas field was predicted.Three typical sites which were close to the top,middle and bottom of produced water wellbore were selected to carry out the scale fouling experiments and the fouling tendency prediction by the saturation index method. The results show that the amount of scaling increases with well depth and reaches a dynamic equilibrium state of scale attachment and detachment after a certain time. The scaling tendency using model method is in good agreement with the experiments.The method is proved reliable and can provide guidance for anti-scaling in produced water system.