基于井筒温度剖面的热采水平井找水方法

Research on water detection method for thermal recovery horizontal well based on wellbore temperature profile

热采水平井出水机理复杂,寻找出水点是高效堵水的关键。针对目前常用找水方法具有仪器起下困难、油井动态测量成本高等问题,提出了一种基于井筒温度剖面的热采水平井找水方法。基于传热学及多相管流理论,在井筒内油水两相流体流动的状态下,综合井筒处热对流及热传导、焦耳-汤姆生效应以及重力做功产生的井筒温度变化,与重力及剪切力做功引起的井筒压力降,建立热采水平井生产阶段井筒温度计算模型,得到生产时水平井井筒温度剖面。由于生产过程中水平井井段的出水会导致该段流体温度异常,通过对比理论剖面与实测温度曲线的差异,可以确定出水位置,根据温度可进一步分析产出水来源。

The water production mechanism of thermal recovery horizontal wells is complicated,and detect the water break⁃through point is the key to efficient water blocking.At present,the common water detection methods have difficulty in rais⁃ing and lowering the instrument and high cost of dynamic test in oil well.Therefore,this paper proposes an analysis method of the wellbore temperature profile to detect the water breakthrough point of thermal recovery horizontal wells.According to the theory of heat conduction and multiphase pipe flow,under the condition of oil-water two-phase flow in the wellbore,we analyze the heat convection and heat conduction at the wellbore,the Joule-Thomson effect,the temperature change of the wellbore induced by the work of gravity,and the pressure drop of the wellbore caused by the joint work of gravity and shear.Then we construct a calculation model of wellbore temperature of thermal recovery horizontal wells during production,ob⁃taining the wellbore temperature profile of the horizontal wells.Since the water production from the horizontal section dur⁃ing production will cause abnormal fluid temperature in this interval,the water breakthrough point can be determined by comparing the difference between the theoretical profile and the measured temperature curve.Then the source of the pro⁃duced water can be analyzed according to the temperature.