多相流全瞬态温度压力场耦合模型求解及分析

Solution and Analysis of Fully Transient Temperature and Pressure Coupling Model for Multiphase Flow

何淼 柳贡慧 李军 李梦博 查春青 李根

He Miao Liu Gonghui Li Jun Li Mengbo Zha Chunqing Li Gen

中国石油大学(北京)石油工程学院, 北京 102249; 北京信息科技大学, 北京 100192; 中国石油辽河油田公司茨榆坨采油厂, 辽宁辽中 110206

College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing, 102249, China; Beijing Information Science & Technology University, Beijing, 100192, China; Ciyutuo Oil Production Plant, PetroChina Liaohe Oilfield Company, Liaozhong, Liaoning, 110206, China

为准确掌握高温高压条件下环空多相流的流动特性,基于井筒多相流、传热学理论,充分考虑循环流体物性参数随温度压力的变化,建立了适用于深井、超深井的井筒多相流全瞬态温度压力场耦合模型,并提出了迭代求解算法,以塔里木油田某深井为例分析了井筒瞬态温度、压力耦合变化规律.结果表明:循环8 h后井底钻井液的密度由1 360 kg/m3升至1 460 kg/m3,塑性黏度由8.6 mPa·s升至13.8 mPa·s;开始循环时井底压力迅速降低,循环0.2 h时降至最低,然后逐渐升高,最后趋于稳定;井底钻井液的密度和塑性黏度随循环时间增长而增大;气侵量对井底压力的影响最大,钻井液地面密度、排量、井口回压次之,钻井液地面塑性黏度的影响最小.分析结果可为深井、超深井水力参数设计提供理论指导.

To accurately identify the features of annular multiphase flow in high temperature high pressure (HTHP) conditions, a fully transient temperature and pressure coupling model for multiphase flow in deep or ultra-deep wells was established according to the theory of wellbore multiphase flow and heat transfer. Considering the changes of physical parameters of circulating fluid with temperature and pressure, and the iterative algorithm was proposed. In this paper, a deep well in Tarim Oilfield was analyzed for the wellbore transient temperature and pressure coupling. The results indicated that the drilling fluid density at bottomhole increased from 1 360 kg/m3 to 1 460 kg/m3, and the plastic viscosity increased from 8. 6 mPa·s to 13.8 mPa·s after circulating for 8 hours. Both the drilling fluid density and the bottomhole plastic viscosity increased over the circulating time, and further, the bottomhole pressure dropped linearly at initial circulation and then to the minimum at 0.2 h. Later, it increased logarithmically and tended to be finally stable. In view of the impact on bottomhole pressure, the factors are were prioritized in a descending order as follows:gas influx, surface drilling fluid density, displacement, wellhead back pressure, and surface drilling fluid plastic viscosity. An analysis of the results could provide certain theoretical guidance for the hydraulic parameter design of deep and ultra-deep wells.

国家自然科学基金重点项目“控压钻井测控理论及关键问题研究”(编号:51334003),国家自然科学基金面上项目“深层碳酸盐岩地层与井筒耦合作用机理与压力自动控制方法研究”(编号:51274221)、“控压钻井井筒多相流体瞬态变质量流动理论及工况解释方法研究”(编号:51274045)和“基于模型预测控制理论与状态机架构的控压钻井压力控制方法研究”(编号:51374223)联合资助.

https://doi.org/10.11911/syztjs.201502005