偏心环空中幂律流体层流螺旋流流动规律的研究

RESEARCH ON THE LAW OF LAMINAR HELICALFLOW OF POWER-LAW FLUID INECCENTRIC ANNULI

在石油钻井工程中,特别是在定向井、水平井正常钻进时,井眼中的上返钻井液液流属于偏心环空层流螺旋流,而不是轴向流。作者依据流体力学原理,研究了幂津流体在偏心环空中的层流螺旋流流动规律,探讨了视粘度分市,速度分布及计算流量和压降的方法。文中还将部分结果与同心环空流理论及两相流实验值作了对比。经过验证表明:文中新的理论公式可用于钻井水力参数计算。

The upper flow of drilling fluids in the boreholes is an eccentric laminar helical one, not an axial flow, when wells, especially directional and horizontal wells, are being drilled. The study on the laminar helical flow of drilling fluids in eccentric annuli is just at its beginning in the world. Based on the principle of fluid mechanics, the law of laminar helical flow of power-law fluid in eccentric annuli is thoroughly studied in this paper. The apparent viscosity, velocities, calculating methods of flow rate and pressure loss of laminar helical flow of Power-law fluid are presented. On the basis of theoretical studies some new results of present paper are compared with the theories of the helical flow in concetric annuli and tests of liquid/ solid flow. The tests show that the theoretical formulae can be applied to for calculation in drilling engineering.