摘要
钻井过程中,为减少井下高温高压环境下钻井液溢流、漏失、井涌和气侵等异常状况,需要准确地监测井底压力。当前井底压力监测计算模型未考虑井下钻井液温度和环空压耗的影响,使得测算的井底压力不够准确,导致钻井风险升高,因此提出了一种基于温压梯度与井眼偏心的深井小井眼井底压力分段监测方法。首先研究了钻井液在井筒环空中的流动压耗,分析了深井小井眼下钻进过程中环空偏心对环空压耗的影响,建立了基于环空偏心度的压耗分段解算模型;然后研究深井小井眼中钻井液密度受温度、压力、油水比等参数影响的特性,建立了基于温压梯度下密度解算模型以及静液柱压力计算模型,构建了正常钻进工况下分段井底压力监测模型,最终形成了一套基于温度、压力梯度和环空压耗的深井小井眼井底压力分段监测系统。现场应用表明,通过与现场PWD实测井底压力对比分析,基于温压梯度的分段井底压力监测结果误差小于±0.5 MPa,测量精度可满足现场压力实时监测要求。该井底压力监测系统为现场安全、快速、高效钻进提供了数据支撑,对未来深部油气资源勘探开发具有积极的指导意义。
During drilling,in order to reduce abnormal conditions such as drilling fluid overflow and loss,well kick and gas influx under downhole high temperature and high pressure environment,it is necessary to accurately monitor the bottom hole pressure.The current bottom hole pressure monitoring calculation model does not consider the influence of downhole drilling fluid temperature and annular pressure loss,so that the measured bottom hole pressure is not accurate enough,resulting in increased drilling risk.Therefore,this paper proposes a piecewise monitoring method of bottom hole pressure in deep and slim holes based on temperature-pressure gradient and borehole eccentricity.First,the flowing pressure loss of drilling fluid in the wellbore annulus is studied,the influence of annulus eccentricity on the annular pressure loss during drilling deep and slim holes is analyzed,and a piecewise calculation model of pressure loss based on annulus eccentricity is established.Then,the characteristics of drilling fluid density affected by temperature,pressure,oil-water ratio and other parameters in deep and slim holes are studied.The density calculation model and hydrostatic column pressure calculation model based on temperature-pressure gradient are built up,and the piecewise bottom hole pressure monitoring model under normal drilling conditions is constructed.Finally,a set of bottom hole pressure piecewise monitoring system based on temperature-pressure gradient and annular pressure loss in deep and slim holes is formed.Field application shows that the error of piecewise bottom hole pressure monitoring results based on temperature-pressure gradient is less than±0.5MPa through the comparative analysis with field PWD measured bottom hole pressure,and the measurement accuracy can meet the requirements of the real-time monitoring of the field pressure.The bottom hole pressure monitoring system provides data support for safe,fast and efficient drilling on site,and has a positive guiding significance for the exploration and development of deep hydrocarbon resources in the future.
作者
毛敏
吴昊晟
倪朋勃
孙源
杨毅
马慧涛
MAO Min;WU Haosheng;NI Pengbo;SUN Yuan;YANG Yi;MA Huitao(China France Bohai Geoservices Co.,Ltd.,Tianjin 300457,China;Exploration and Development Research Institute of PetroChina Jidong Oilfield Company,Tangshan,Hebei 063004,China)
出处
《录井工程》
2022年第4期29-34,40,共7页
Mud Logging Engineering
关键词
深井
小井眼
井底压力
环空压耗
环空偏心
温度梯度
压力梯度
监测系统
deep hole
slim hole
bottom hole pressure
annular pressure loss
annulus eccentricity
temperature gradient
pressure gradient
monitoring system
作者简介
毛敏,高级工程师,1973年生,1995年毕业于长江大学矿场地球物理专业,现在中法渤海地质录井公司从事石油录井技术与管理工作,通信地址:300457天津市经济技术开发区信环西路19号天河科技园1号楼3层,电话:(022)65310705,E⁃mail:maomin@cfbgc.com。
