针对稠油非达西流动特征,引入稠油油藏有效动用理论,根据蒸汽吞吐开发时井筒周围流体的流动状态进行分区,采用等值渗流阻力法,考虑拟启动压力梯度,分别推导直井和水平井蒸汽吞吐开发方式下的产能预测公式.通过数值计算,分析生产压差、拟启动压力梯度、开发方式以及开发井型等因素对稠油油藏有效动用范围和产能的影响.分析结果认为:生产压差越大,油藏有效动用半径先增加,后趋于平缓,日产油量增加;拟启动压力梯度越大,有效动用半径逐渐变小,且递减幅度逐渐变缓,日产油量逐渐降低;拟启动压力梯度对天然能量和蒸汽吞吐开采的影响均不能忽略,且对蒸汽吞吐开采影响较大;直井和水平井产能均随拟启动压力梯度增加而减小,且水平井产能降低幅度较大.该研究为现场准确评估油井产能,选择合理开发方案提供了理论依据.%In this paper, the effective drainage theory on heavy oil reservoirs was introduced to deal with the non-Darcy flow characteristics of heavy oil.Zoning was carried out according to the flow regimes of fluids around wellbores in the process of steam huff and puff.By virtue of equivalent flowing resistance method, the productivity prediction formulas for vertical wells and horizontal wells in the development pattern of steam huff and puff were derived by taking into consideration the pseudo threshold pressure gradient.Then, the effects of production pressure difference, pseudo threshold pressure gradient, development mode and development well type on the effective drainage area and productivity of heavy oil reservoirs were analyzed based on numerical calculation.It is indicated that with the increasing of production pressure difference, the effective drainage radius of oil reservoir increases to a stable value and the daily oil production declines gradually.With the increasing of pseudo threshold pressure gradient, the effective drainage radius and the daily oil production decreases gradually and decreasing amplitude of effective drainage radius gets gentle gradually.The effect of pseudo threshold pressure gradient on natural energy and steam huff and puff shall not be neglected and its effect on the latter is more.The productivity of vertical wells and horizontal wells decreases with the increasing of pseudo threshold pressure gradient, and the productivity decline amplitude of horizontal wells is higher.The research results provide the theoretical basis for the accurate productivity evaluation of oil wells on site and the rational selection of development plans.
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