海上钻井中气液流型转化和含气率预测的研究  

Research on gas-liquid flow pattern transformation and gas holdup prediction in offshore drilling

作　　者：闫平 张诚成 薛宪波 张洪杰 张文博[1] YAN Ping;ZHANG Chengcheng;XUE Xianbo;ZHANG Hongjie;ZHANG Wenbo(Integrated&New Energy Division of China Oilfield Services Co.,Ltd.,Tianjin 300459,China)

机构地区：[1]中海油田服务股份有限公司一体化和新能源事业部,天津300459

出　　处：《石油化工应用》2023年第1期74-79,共6页Petrochemical Industry Application

摘　　要：控压钻井能够精确控制井底当量密度,降低窄压力窗口井控、井漏风险,从而实现海上油田安全高效钻进,而准确预测多相流压力是进行井筒压力安全控制的基础。考虑到深水钻井同井段边界上存在多相流计算不收敛、环空含气率预测不精准等问题,本文通过室内实验测量不同气液相表观速度下的空隙率波及截面气液相分布,研究了钻井液屈服应力和表观黏度对流型转化的影响规律,建立了井筒环空气液两相流型转化判据,并考虑到深水钻井不同井段边界上多相流计算不连续的难题,建立了适用于全井段的气相体积分数预测模型。结果表明,随表观黏度增大,泡状流到段塞流转化边界左移,段塞流到搅动流转化边界左移,搅动流到环雾流转化边界向右下移动。新提出的截面含气率关系式与前人的实验数据吻合度较高、预测误差较小,能够满足工程需要,可为井筒多相流动压力的准确计算提供理论依据。Managed pressure drilling can accurately control the bottom-hole equivalent circulating density and reduce the risk of well control and lost circulation in narrow pressure window to achieve a safe and efficient drilling in offshore fields.Accurate prediction of multiphase flow pressure is the basis for wellbore pressure control.Considering the problems of non-convergence of multiphase flow calculation and inaccurate prediction of annular gas fraction on the boundary of the same well interval in deep water drilling,this paper measures the void fraction and distribution of gas-liquid section under different gas-liquid phase superficial velocities through laboratory experiments.It also studied the influence of drilling fluid yield stress and apparent viscosity on flow pattern transformation and established the annular gas-liquid two-phase flow pattern transformation criterion.A forecasting model of gas volume fraction suitable for the whole wellbore section is established,which considered the problem of discontinuity in multiphase flow calculation at the boundaries of different well sections in deep water drilling.The results show that with the increase of apparent viscosity,the transition boundary between bubbly flow and slug flow moves to the left,the transition boundary between slug flow and agitation flow moves to the left,and the transition boundary between agitation flow and annular mist flow moves to the right and down.The newly proposed cross-section gas holdup relationship is in good agreement with the previous experimental data,and the prediction error is small,which can meet the needs of engineering,and can provide a theoretical basis for the accurate calculation of wellbore multiphase flow pressure.

关 键 词：控压钻井 气液两相 流型转化 气相体积分数 

分 类 号：TE249[石油与天然气工程—油气井工程]