SAGD井挤液扩容对循环预热及生产的影响

Effects of SAGD well squeeze dilatation on the circulating preheating and production

SAGD井挤液扩容储层改造技术已经在新疆油田得到广泛应用,显著缩短了预热周期,降低了经济成本和环境压力;然而,如何评价挤液扩容对后期循环预热和SAGD生产的影响目前仍不清楚。针对该问题,首先采用有限元方法计算某SAGD井挤液扩容引起的储层变形,其次采用CMG分析基于扩容后的储层模型的SAGD预热及生产情况,并对比未采用扩容的情况,评价了挤液扩容的作用效果。研究表明,储层挤液扩容后,在扩大蒸汽注入空间和增强注入水与蒸汽之间的热对流的共同作用下,可以大幅缩短循环预热周期,略增大最终产量。地质力学有限元计算和油藏数值模拟相结合的分析方法能为现场优化挤液施工提供工程指导。

The reservoir stimulation technology of SAGD well squeeze dilatation has been widely applied in Xinjiang Oilfield, and it obviously shortens the preheating period and reduces the economic cost and environmental pressure. At present, however, it is not defined how to evaluate the effect of squeeze dilatation on later circulating preheating and SAGD production. To deal with this situation, the reservoir deformation caused by squeeze dilatation in one certain SAGD well was first calculated by means of finite element method. Then, the SAGD preheating and production based on post-dilatation reservoir model were analyzed using CMG and compared with the situation without dilatation. Finally, the action effects of squeeze dilatation were evaluated. It is indicated that after squeezes dilatation in a reservoir, under the joint effect of enlarging the steam injection space and enhancing the heat convection between injected water and steam, the circulating preheating period is shortened greatly and the ultimate production is increased slightly. The analysis method combining the geomechanical finite element calculation and the numerical reservoir simulation together can provide the engineering guidance for on-site optimal liquid injection.