无隔水管钻井当量循环密度计算模型  

Calculation Model of Equivalent Circulation Density in Riserless Drilling

作　　者：江文龙 樊洪海[1] 纪荣艺[1] 刘玉含 Jiang Wenlong;Fan Honghai;Ji Rongyi;Liu Yuhan(College of Petroleum Engineering,China University of Petroleum(Beijing))

机构地区：[1]中国石油大学(北京)石油工程学院

出　　处：《石油机械》2019年第6期61-66,72,共7页China Petroleum Machinery

基　　金：国家科技重大专项“钻井工程设计邻井信息分析系统及重点井钻井作业风险远程实时预警软件开发与应用”(2016ZX05020006-005)

摘　　要：关于无隔水管钻井在钻柱未充满工况下的井筒温度和压力模型还未见报道。鉴于此,推导了保证无隔水管钻井钻柱内充满钻井液的最低海面泵排量(零立压排量)的计算公式。针对钻柱未充满工况,建立了无隔水管钻井稳态温度计算模型,并在考虑温度和压力对钻井液密度影响规律的基础上建立了当量循环密度( ECD )计算模型。研究结果表明:零立压排量随水深增加而增加,随井深增加而减小;水深越大,相同排量下的平衡液面深度距平台越远;深水无隔水管钻井的井筒温度变化规律与陆上井筒温度变化规律一致,但温度要低很多,因此井底压力和 ECD 变化也较小;由于深水井高温高压窄密度窗口的特点,所以计算井底压力和 ECD 时需要考虑温度模型。研究结果对无隔水管钻井水力参数的确定具有一定的指导意义。The wellbore temperature and pressure model for riserless drilling with unfilled drillpipe has not been reported.In view of this, the formula for calculating the minimum surface pump displacement (zero standpipe pressure displacement) for filling drillpipe during riserless drilling is derived.For the condition of unfilled drill string, a steady-state temperature calculation model for the riserless drilling is established.Considering the influence of temperature and pressure on the drilling fluid density, an equivalent circulation density ( ECD ) calculation model is established.The study results show that the zero standpipe pressure displacement increases with water depth and decreases with well depth.Deeper water depth results in the farther equilibrium liquid level depth from the platform.The wellbore temperature of deep water riserless drilling is consistent with the temperature change of the onshore wellbore, but the temperature is much lower, resulting in smaller change of the bottomhole pressure and ECD.However, due to the characteristics of high-temperature and high-pressure narrow-density windows in deepwater wells, temperature influence needs to be considered when calculating bottomhole pressure and ECD.The study could provide some guidance for the determination of hydraulic parameters of riserless drilling.

关 键 词：无隔水管钻井 零立压排量 平衡液面 稳态温度 井底压力 ECD 

分 类 号：TE951[石油与天然气工程—石油机械设备]