【摘要】 根据水平井压井的基本原理,考虑环空摩阻、流体流型影响下的计算误差,分析了水平井与直井压井控制立压变化的比较误差。以直井井控理论、多相流理论为基础,建立了水平井井控三相流理论模型,采用有限差分方法对模型进行了数值化求解。算例分析结果表明,在水平井立压控制过程中,如果按直井方式压井,不仅在初始立压点和终了立压点存在误差,而且在造斜点、稳斜点处也存在较大的误差,这将对水平井井控作业产生一定影响。在水平井压井过程中,直到溢流全部移出水平段时水平井的井口套压才开始逐渐增加;岩屑床的存在使水平段和造斜段的环空尺寸减小,对流体流速有一定影响,使井口套压比不考虑其存在的情况时偏高;水平井曲率半径、水平段长、水平段微小倾角、多个造斜率等因素对井口套压影响不大,而井眼尺寸、压井排量、溢流量等因素对井口套压影响较大。更多还原

【Abstract】 Considering the calculation errors brought by annular friction and fluid flow pattern,the compared errors of stand-pipe pressure control for horizontal and vertical wells killing process were anzlyzed on the basis of the principle of horizontal well killing.Based on the theory of multiphase transient flow and the general principle of well control of vertical well,a comprehensive theoretical model dealing with dynamic well control for horizontal well was developed.The finite difference method was adopted for solving mathematical equations.The results show that errors can be found not only at initial circulating pressure point and final circulating pressure point but also at kick-off point and hold angle point in horizontal well killing process.For horizontal well,the surface casing pressure gradually increases until kick removed from horizontal section.The annulus space is reduced by cuttings bed so that the velocity of the fluid and the surface casing pressure increase.The curvature radius,horizontal section length,slight horizontal inclined angle,and multi-buildup rates have little effect on surface casing pressure while other parameters such as the well bore size,killing rate and kick size have considerable influence on surface casing pressure.更多还原