非均质变异系数对S/P驱各小层驱油效果及动态特征的影响

The Influence of Coefficient of Heterogeneous Variation on S/P Displacement Effect and Dynamic Characteristics of Every Single Layer

申乃敏 李华斌 张振平 张连锋 姚君波 李正民

SHEN Nai-Min LI Hua-Bin ZHANG Zhen-Ping ZHANG Lian-Feng YAO Jun-Bo LI Zheng-Min

利用数值模拟技术，在45℃及大庆地层水条件下，研究了油层非均质变异系数(Vk) 对表面活性剂/聚合物（S/P）复合驱时各小层驱油效果及动态特征的影响。用油藏数值模拟软件建立理想地质模型，纵向分为7个小层，Vk相同时（Vk>0），1～7小层的渗透率从小到大。当0＜Vk＜0.3 时，各小层及全区的最终采出程度受Vk的影响小，稳定在60% OOIP左右。随着Vk的增大，第1～4小层以及全区的最终采出程度随着Vk的增大而降低；而第5～7小层的最终采出程度基本稳定。Vk越大，低渗小层的采出程度越低。当Vk=0.9时，第1～7小层的采出程度分别为OOIP的3.39%、8.22%、21.13%、41.83%、63.38%、63.95%、63.97%。对应的，第1～7小层的S/P体系注入量分别为0.0014、0.0031、0.0077、0.02、0.051、0.1183、0.1971PV。与水驱采收率相比，中、低渗层S/P驱采收率增幅高于高渗层，且渗透率不同，采收率增幅最大值对应的Vk不同。第1～5小层采收率增幅最大值对应的Vk分别为0.3、0.3、0.5、0.72和0.9；第6、7 小层的采收率增幅受Vk的影响较小。当全区综合含水达到98%时，随Vk增大，各小层的含水率曲线与对应的采出程度曲线的变化趋势基本一致，说明最终采出程度低的层位，同时也是含水率低的层位。

The influence of the oil reservoir heterogeneity variation coefficient (Vk) on surfactant/polymer (S/P) displacement effect and dynamic characteristics of every thin stratum was researched by numerical simulation under the conditions of Daqing oilfield at 45℃ . The ideal geological model was established by the reservoir numerical simulation software, which was divided into seven single layers. When Vk（Vk>0）was the same，the permeability of 1—7 single layer increased gradually. When Vk was from 0 to 0.3, the recovery degree of every single layer and all-region was stability in 60% or so and was affected little by Vk. The final recovery degree of 1—4 single layer and all-region decreased with increasing Vk and that of 5—7 single layer was stable basically. The greater Vk, the lower recovery degree of low permeability single layer was. When Vk was of 0.9, the recovery degree （OOIP） of 1—7 single layer was 3.39%， 8.22%， 21.13%， 41.83%， 63.38%， 63.95% and 63.97%，respectively. Correspondingly, S/P system injection quantity of 1—7 single layer was 0.0014, 0.0031, 0.0077, 0.02, 0.051, 0.1183 and 0.1971 PV, respectively. Compared with water-flooding, the recovery ratio increment of S/P displacement of medium, low permeability layer was higher than that of high permeability layer. Vk corresponded the maximum of recovery ratio increment was different with different permeability. Vk corresponded the maximum of 1—5 single layer recovery ratio increment was 0.3, 0.3, 0.5, 0.72 and 0.9, respectively, and that of 6 and 7 single layer was affected little by Vk. When the comprehensive water cut was up to 98%, the water cut curve of every thin stratum was in line with the corresponding curve of eventually recovery degree in different Vk conditions. So as to further illustrate, the water cut of the layer with low final recovery degree was low also.