碳酸盐岩溶洞数值模拟及地震识别  

NUMERICAL SIMULATION AND SEISMIC RECOGNITION OF CARBONATE KARST CAVE

作　　者：叶勇[1] 杨子兴[2] 李佩[2] 潘宏勋[2] 

机构地区：[1]中国地质大学 [2]中国石化石油勘探开发研究院南京石油物探研究所

出　　处：《天然气工业》2007年第3期43-45,共3页Natural Gas Industry

基　　金：中国石化股份有限公司重大科研项目(P01062)资助。

摘　　要：碳酸盐岩岩溶性储集层具有很强的非均质性,其预测非常困难。地震正演可以了解碳酸盐岩风化壳地震反射同相轴的变化特征和来自内幕洞穴的地震反射、散射等波场特征。应用高阶差分数值模拟方法,对一系列不同尺度、不同充填物(速度)的溶洞模型进行了系列的正演数值模拟,并对具地震反射特征及反射波振幅进行了综合分析。研究表明:①溶洞型油气藏的地震波沿溶洞边缘往复滑行形成多次绕射波,在地震剖面上表现为“串珠状”强短反射段;②溶洞横向尺度的大小对振幅影响很大,尺度越大,振幅越大;③溶洞充填物速度越高,其振幅越小。通过正演数值模拟研究,建立了溶洞的识别模式,将其应用于塔河油田碳酸盐岩储层的地震预测,效果较好,提高了钻井符合率。It is very difficult to predict carbonate karst reservoir due to serious heterogeneity of the reservoir. The forward modeling can reflect the variation of the reflection events from the carbonate weathering crust and the wavefield properties from the inner caves, such as the seismic reflection and seismic dispersion. The paper applied highorder differential numerical simulation to perform a series of forward numerical simulations for various caves with different sizes and filling material (different velocities) , and comprehensively analyzed the seismic reflection properties and reflection amplitude of the various cave models. The study indicates that the seismic wave from the karst cave reservoir slides back and forth along the cave edges to form multiple diffraction wave which behaves as strong and short reflection segments of shoestring in the seismic section; the horizontal size of the karst cave has large effects on the seismic amplitude, the larger the horizontal size, the stronger the amplitude; and the higher the wave velocity in the cave filling, the weaker the seismic amplitude. The recognition patterns of the karst caves were built by forward numerical simulation, and the study results were applied into the seismic prediction of the carbonate reservoirs in Tahe oil field, good results were gained and the drilling successful rate was increased.

关 键 词：碳酸盐岩 溶洞性油气藏 地震反射 特征 数值模拟 识别 

分 类 号：P631.4[天文地球—地质矿产勘探]