AVO属性分析在天然气水合物地震解释中的应用  

THE APPLICATION OF AVO ATTRIBUTE ANALYSIS IN SEISMIC INTERPRETATION OF GAS HYDRATE

作　　者：梁劲[1] 梁金强[1] 王宏斌[1] 沙志彬[1] 

机构地区：[1]广州海洋地质调查局,广东广州510760

出　　处：《物探化探计算技术》2008年第1期22-26,共5页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：广州海洋地质调查局科研项目资助(GZJK200605)

摘　　要：利用AVO(Amplitude Versus Offset)属性分析技术,对南海北部测线B进行了AVO属性处理,结合BSR(Bottom Simulating Reflector),振幅空白带以及波形极性反转等多种水合物赋存信息,对水合物成矿带及游离气带的AVO属性特征进行了综合研究。结果表明:①AVO1和AVO9可用于检测BSR和水合物成矿带;②AVO4、AVO6、AVO9用于游离气带的检测;③AVO1高截距值表示上、下层P波速度差值大,弱反射或空白反射表示水合物分布均匀,是水合物富集和稳定的表现;④AVO4高值表示有游离气存在,强反射特征为游离气顶的反射;⑤AVO6正值,表示有游离气存在,强反射的发育厚度代表游离气的发育厚度;⑥AVO9低幅值表示水合物成矿带,正值表示游离气带。研究结果表明,高精度AVO分析不仅可以帮助寻找水合物矿点,还可以进一步判定水合物的富集层位。Combining with several gas hydrates existing information including bottom simulating reflectors BSRs,amplitude blanking,waveform reverses etc.the AVO attributes of the gas hydrate belt and free gas belt were integrally researched in this paper based on the seismic profile B in the north slope of the South China Sea by AVO attribute analysis technology.The result shows that:(1) AVO1 and AVO9 can be used to detect BSR and gas hydrate belt;(2) AVO4,AVO6 and AVO9 can be used to detect free gas belt;(3) High intercept values of AVO1 suggest that the difference of P-wave velocity in the neighboring strata is high,while weak reflection or blank reflection does that the uniform distribution of gas hydrates and the gas hydrates belt might be enriched and steady;(4) The high values of AVO4 suggest the free gas existing,while the strong reflection suggest the top of free gas;(5) The plus values of AVO6 suggest the free gas existing while the thickness of strong reflection suggest the thickness of free gas;(6) The low values of AVO9 suggest the gas hydrates belt while the plus values suggest the free gas belt.The study reveals that the high-resolution AVO analysis is useful not only to search the hydrate spot,but also to estimate the rich layer of gas hydrate.

关 键 词：AVO属性 天然气水合物 地震解释 

分 类 号：TE122[石油与天然气工程—油气勘探]