鱼骨注汽水平井SAGD在风城油田超稠油油藏中的应用

Application of SAGD Technology with Fishbone Steam-Injection Horizontal Well in Super Heavy Oil Reservoirs

在非均质稠油油藏蒸汽辅助重力泄油开发中,为加快蒸汽腔扩展和降低夹层影响,提出了鱼骨水平井注汽方式。以风城油田A井区为例,利用数值模拟技术,分析了影响鱼骨注汽水平井蒸汽辅助重力泄油生产效果的主要因素,优化了分支形态及关键注采参数。研究结果表明,分支的水平位移、垂向位移与井组生产效果呈正相关,分支两侧交错分布的效果要优于分支两侧对称分布及同侧分布;当鱼骨注汽水平井上方存在夹层时,分支穿过夹层的生产效果最优。实际应用表明,鱼骨注汽水平井的初期日产油量和油汽比,均高于同条件下的无分支水平井,该方式具有一定优势,可供同类油藏开发借鉴。

In order to accelerate the expansion of steam chamber and to reduce the impact of interlayers during SAGD development for heterogeneous heavy oil reservoirs,a steam injection method with fishbone horizontal well is put forward.Taking Wellblock A of Fengchengoilfield as an example,main factors influencing production effects of SAGD technology with fishbone steam-injection horizontal well are analyzed and branch shapes and key injection-production parameters are optimized by using numerical simulation technique.The study results show that horizontal and vertical displacements of branches are positively correlated with production effects of well groups,and theproduction effect of staggered branch distribution is better than those of symmetry and same-side branch distributions.When interlayers exist above fishbone steam-injection horizontal wells,the optimum production effect can be gained when the branches go across the interlayers.The actual application shows that both initial daily oil production and oil/steam ratio of the fishbone steam-injection horizontal wellsare higher than those of horizontal wells without a branch under the same conditions.The production method has certain advantages andcan be guidance for similar reservoir development.