蒸汽辅助重力驱生产井井筒举升工况分析

蒸汽辅助重力驱(Steam Assisted Gravity Drainage)SAGD技术是水平井结合注蒸汽工艺技术在开采稠油中的具体运用,在我国辽河油田开始了现场试验。为了分析生产井能否维持自喷并进行正常的SAGD开采,本文打破了常规的计算方法,首次将井眼轨迹计算技术引人多相流动的计算中,应用多相流体力学和传热学原理,建立了井筒内的能量平衡方程及热传导方程。通过对汽液两相流体在倾斜井筒中总传热系数方程式、热传导方程式及能量平衡方程式的求解,得出了计算井筒内任意点处压力、干度及其他物性参数的计算公式,总结出一套新的计算方法,并编制了计算软件。理论计算与现场实测数据的对比表明,该理论是正确的,利用该软件所得计算结果可以作为油田SAGD生产举升方案设计的依据。

BOREHOLE LIFTING CONDITIONS OF PRODUCING WELL WITH STEAM ASSISTED GRAVITY DRAINAGE (SAGD)

Steam assisted gravity drainage (SAGD) is a specific application of the combination of horizontal well with steam injectionrecovery technique to heavy oil reserves. SAGD was first used in Canada, and today it has been introduced and experimented inLiaohe Oil field in China. To analyze the producing well can sustain free flow and make SAGD efficient in normal ways. We introducd the survey calculation technique of wellbore trajectory into the calculation of multiphase flow,and developed the energyequilibrium equation and the heat conduction equation in boreholes based on the principle of multiphase hydromechanics and heatconduction. The equations to calculate pressure,dryness fraction and other physical parameters at any point along the boreholehave been obtained by resolving the equations of total heat transfer coefficient,heat conduction,energy balance of the gas-liquidtwo-phase fluid in inclined wellbores. A new set of calculation methods are provided and the corresponding computer programwas written. Comparing the theoretical calculation results with the actual measurement data shows that the theory presented inthis paper is accurate,and its calculation results can provide the field lifting plan of SAGD production with the theoretical foundation.