层状吸收介质地震反射参数的计算
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摘要
根据大庆长垣北地区的地震参数建立了视等厚层状吸收介质模型,并计算了地层层速度和地层吸收衰减因子.选择主频为200Hz的雷克子波为激发地震子波,由浅至深(0.5～3.0s)计算地震反射参数.计算结果表明:地层的吸收衰减和球面扩散导致地震反射波振幅差异大,随深度增加振幅迅速衰减,振幅衰减主要发生在1.5s前的中浅地层;地层的高频吸收衰减效应导致深层地震反射波主频率降低、频带变窄;随深度增加地震层速度明显增大,根据主频率和层速度计算得到的地震垂向分辨率明显降低.该结果对实际地震工作具有理论指导意义.
The models of layer absorption media are built based on the seismic parameters of Daqing placanticline. The velocity and absorbing factor of every stratum are calculated as well. The Ricker wavelet whose main frequency is 200 Hz is chosen as the exciting wave and the reflected waves from 0.5 to 3.0 s are calculated. The result shows that there is difference in the amplitudes caused by the absorption and attenuation of strata and spherical diffusion. With the increment of depth the amplitude attenuates rapidly and the main attenuation occurs in 1.5 s which is of the medium depth. With the absorption and attenuation of strata the main frequencies get lower and the frequency bands get narrower. With the increment of depth the strata's velocity increases obviously, the vertical resolution which is derived from the calculation of the main frequency and strata's velocity is greatly reduced. The result will be instructive to the actual seism.
The models of layer absorption media are built based on the seismic parameters of Daqing placanticline. The velocity and absorbing factor of every stratum are calculated as well. The Ricker wavelet whose main frequency is 200 Hz is chosen as the exciting wave and the reflected waves from 0.5 to 3.0 s are calculated. The result shows that there is difference in the amplitudes caused by the absorption and attenuation of strata and spherical diffusion. With the increment of depth the amplitude attenuates rapidly and the main attenuation occurs in 1.5 s which is of the medium depth. With the absorption and attenuation of strata the main frequencies get lower and the frequency bands get narrower. With the increment of depth the strata's velocity increases obviously, the vertical resolution which is derived from the calculation of the main frequency and strata's velocity is greatly reduced. The result will be instructive to the actual seism.
引文
[1] 唐建人,李勤学.高分辨率地震勘探理论与实践[M].北京:石油工业出版社,2001.12-14.
[2] 董敏煜.地震勘探[M].东营:石油大学出版社,2000.180-183.
[3] 李庆忠.走向精确勘探的道路[M].北京:石油工业出版社,1993.81-85.
[4] 钱绍瑚,刘来祥.零相位子波的垂向分辨率[J].石油物探,1988,27(2):1-9.
[5] 凌 云.大地吸收衰减分析[J].石油地球物理勘探,2001,36(1):1-8.
[6] 钱绍瑚.高分辨率勘探与地震仪器[J].物探与化探,1995,19(2):114-121.
[7] 俞寿朋.高分辨率地震勘探[M].北京:石油工业出版社,1993.35-76.
[2] 董敏煜.地震勘探[M].东营:石油大学出版社,2000.180-183.
[3] 李庆忠.走向精确勘探的道路[M].北京:石油工业出版社,1993.81-85.
[4] 钱绍瑚,刘来祥.零相位子波的垂向分辨率[J].石油物探,1988,27(2):1-9.
[5] 凌 云.大地吸收衰减分析[J].石油地球物理勘探,2001,36(1):1-8.
[6] 钱绍瑚.高分辨率勘探与地震仪器[J].物探与化探,1995,19(2):114-121.
[7] 俞寿朋.高分辨率地震勘探[M].北京:石油工业出版社,1993.35-76.
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