基于分频RGB融合技术的辫状河三角洲储层构型精细解剖

Fine Analysis of Braided River Delta Reservoir Architecture Based on Frequency Division RGB Fusion Technology

单一地震属性由于其多解性强、隐含的地质信息少,在四级、五级储层构型研究中往往难以取得理想的效果,而分频RGB融合技术通过提取有效频带的地震数据体,并利用RGB融合成像凸显地质体的边界,可有效提高稀疏井网油田储层构型研究的精度。利用该方法开展了珠江口盆地陆丰Y油田文昌组五段主力油层的储层构型解剖。结果表明:利用20、35、60 Hz分频RGB融合能较好地识别陆丰Y油田辫状河三角洲分流砂坝和分流河道等不同构型单元的平面展布边界。在辫状河三角洲沉积模式指导下,结合测井划定了五级、四级构型界面,剖析了陆丰Y油田文昌组五段五级、四级构型特征,认为四级构型单元垂向上存在分流砂坝-分流砂坝、分流河道-分流砂坝及分流河道-分流河道3种叠置样式;侧向上存在分流砂坝-分流河道切叠、分流砂坝-分流砂坝切叠以及分流河道-分流间湾切叠3种拼接样式。陆丰Y油田文昌组五段单个五级构型单元宽度为5~7 km,厚度为40~60 m;四级构型厚度为2~10 m,单个四级构型砂坝平面上长度为3~6 km,宽度为2~3 km。

Single seismic attribute is often difficult to achieve ideal results in the study on 4-level and 5-level reservoir architectures due to its strong multi-resolution and less hidden geological information.Frequency division RGB fusion technology can effectively improve the accuracy of reservoir architecture in sparse well pattern oilfield by extracting seismic data of effective frequency band and highlighting the boundary of geological body through RGB fusion images.Frequency division RGB fusion technology was used to analyze the architecture of major reservoir in the fifth member of Wenchang Formation,LFY oilfield,Pearl River Mouth Basin.The results show that the frequency division RGB fusion with 20,35 and 60 Hz can better identify the distributary bar and distributary channel boundary of braided river delta in LFY oilfield,and clearly describe the plane distribution characteristics of different architecture units.Under the guidance of braided river delta sedimentary model,the 5-level and 4-level architecture characteristics of the fifth member of Wenchang Formation in LFY oilfield were analyzed.4-level architecture unit has three vertical superposed styles of distributary bar-distributary bar,distributary channel-distributary bar and distributary channel-distributary channel,and has three lateral splicing styles of distributary bar-distributary channel stacking,distributary bar-distributary bar stacking and distributary channel-inter-distributary bay stacking.The width and thickness of 5-level single architecture unit in the fifth member of Wenchang Formation,LFY oilfield are 5-7 km and 40-60 m;the thickness of 4-level single architecture unit is 2-10 m;the length and width of 4-level single architecture unit are 3-6 km and 2-3 km in the plane.