稠油油藏FAST-SAGD技术储层筛选标准

Reservoir Screening Criteria of FAST-SAGD Technology in Heavy Oil Reservoir

为加速FAST-SAGD技术的现场推广,以阿尔伯塔冷湖先导试验区为研究对象,运用油藏数值模拟软件研究了地层韵律、页岩夹层、漏失层等非均质条件对FAST-SAGD开发效果的影响,通过量化分析得到了FAST-SAGD的储层筛选标准。研究表明：正韵律FAST-SAGD开发效果远远优于反韵律FAST-SAGD,前者要求垂水渗透率之比大于0.15,渗透率级差在4左右,后者要求垂水渗透率之比大于0.25,渗透率级差小于3;注采井间的页岩尺寸约为15 m时,蒸汽的窜流现象能够得到有效控制,页岩夹层位于上部储层1/2及以上位置时,其对蒸汽腔发育的阻碍作用可以忽略;顶底水不利于FAST-SAGD的开发,但对于气顶油藏,当气顶与油藏体积比为0.10~0.20时,保留气顶开采效果较好。明确FAST-SAGD技术对于各种地质因素的适用性,有利于现场稠油开采技术的筛选,规避开发效果欠佳区块,实现稠油油藏的经济高效开发。

In order to accelerate the field promotion of FAST-SAGD technology,a pilot test block in Alberta Cold Lake is studied and reservoir numerical simulation is used to study the effect of strata rhythm,shale interlayer,leakage zone and other heterogeneities on FAST-SAGD performance. The reservoir screening criteria of FAST-SAGD technology is obtained by quantitative analysis. The development of positive-rhythm reservoir with FAST-SAGD is much better that that of reverse-rhythm reservoir. The vertical-horizontal permeability ratio should exceed 0. 15 and permeability contrast should remain about 4 in the development of positive-rhythm reservoir with FAST-SAGD. The vertical-horizontal permeability ratio should exceed0. 25 and permeability contrast should be less than 3 in the development of reverse-rhythm reservoir with FAST-SAGD. Steam channeling can be effectively controlled when the shale interlayer thickness between injection and production wells is less than 15 m. The negative effect of shale interlayer on steam chamber development can be ignored when the shale interlayer is located in the upper half of reservoir. Top and bottom aquifers are unfavorable to the application of FAST-SAGD. Better production performance can be achieved by retaining gas-cap for gas-cap reservoir when the volume ratio of gas-cap and reservoir is 0. 1-0. 2. The research on FAST-SAGD applicability for different geological factors is favorable to the field screen of heavy oil production technologies. The reservoir screening could also avoid unfavorable blocks and achieve cost-effective development of heavy oil reservoirs.