摘要
为了缓解井筒结蜡给海上油田油气开采造成的消极影响,研究了海上结蜡油井的蜡质沉积规律,并建立了一种海上油井井筒结蜡剖面预测新模型。该模型基于对4种现有模型的机理分析,采用理论与试验相结合的方法,综合考虑了分子扩散、剪切弥散和蜡层的老化与剥蚀损失等结蜡机理。通过实例对新模型与4种现有模型的结蜡剖面预测结果进行了对比分析,并结合渤海油田海上结蜡油井的生产数据,检验了新模型对结蜡井筒流体温度和压力的计算精度,新模型计算井口温度的相对误差为1.32%,计算井下压力的相对误差为0.30%,计算精度良好;利用新模型分析了生产时间、产量、含水率和生产气油比等影响结蜡因素的敏感性,认为结蜡厚度随生产时间递增,受产量和含水率的影响较大,受生产气油比的影响相对较小。研究结果表明,新模型能够较为准确地预测海上结蜡电动潜油离心泵油井井筒的结蜡剖面,可以为海上电潜泵结蜡井的清蜡防蜡工艺优选与实施提供指导。
To alleviate the negative effects of wellbore wax deposition in offshore oil and gas production,research on wax deposition in offshore oilfields were carried out and a new forecasting model for wellbore wax deposition profile was established.The new model was developed on the basis of the existing four wax deposition mechanisms with comprehensive consideration to molecule diffusion,shear dispersion,shear erosion and wax layer aging.By using field data,performances of the new model were compared with waxing patterns in the four existing models.Calculation accuracy of wellhead temperatures(WHT)and bottom-hole pressures(BHP)of the new model was verified by using the production data from offshore wells with wax deposition in the Bohai Oilfield.Test results showed that the new model has higher accuracy with a relative calculation error of 1.32% for WHT and 0.30% for BHP,respectively.Sensitivities of influencing factors such as producing time,flow rates,water cut and production GORs were analyzed in the new model,and it indicated that wax deposition thicknesses may increase with the extension of producing time and they are highly sensitive to flow rates and water cut,whereas impacts of productions GOR are relatively low.Research results showed that the new model can accurately forecast the deposition of wax in offshore ESP wells and may provide valuable guidance for wax control and removal.
出处
《石油钻探技术》
CAS
CSCD
北大核心
2017年第4期103-109,共7页
Petroleum Drilling Techniques
基金
中海油能源发展股份有限公司科研项目"渤海油田油水井结蜡结垢预测及防治工艺研究"(编号:GCJSLZBG-1605)部分研究内容
关键词
结蜡剖面
数学模型
温度
压力
敏感性分析
电动潜油离心泵
wax deposition profile
mathematical model
temperature
pressure
sensitivity analysis
electric submersible pump