The quality factor Q is an important parameter because it can refl ect the reservoir attenuated features and can be used for inverse-Q filtering to compensate for the seismic wave energy.The accuracy of the Q estimati...The quality factor Q is an important parameter because it can refl ect the reservoir attenuated features and can be used for inverse-Q filtering to compensate for the seismic wave energy.The accuracy of the Q estimation is greatly significant for improving the precision of the reservoir prediction and the resolution of seismic data.In this paper,the Q estimation formulas of the single-frequency point are derived on the basis of a diff erent-order Taylor series expansion of the amplitude attenuated factor.Moreover,the multifrequency point average(MFPA)method is introduced to obtain a stable Q estimation.The model tests demonstrate that the MFPA method is less aff ected by the frequency band,travel time diff erence,time window width,and noise interference than the logical spectrum ratio(LSR)method and the energy ratio(ER)method and has a higher Q estimation accuracy.In addition,the proposed method can be applied to post-stack seismic data and obtain eff ective Q values of complex models.When the MFPA method was applied to real marine seismic data,the Q values estimated by the MFPA method with the 1st–4th order showed good consistency with each other.In contrast,the Q values obtained by the ER method were larger than those of the proposed method,while those estimated by the LSR method signifi cantly deviated from the average values.In conclusion,the MFPA method has superior stability and practicability for the Q estimation.展开更多
In this paper, we give two transformation formulas for q _series using two simple properties of q _ultraspherical polynomials. Using these transformations and the well_known Rogers_Ramanujan identities, we provide ...In this paper, we give two transformation formulas for q _series using two simple properties of q _ultraspherical polynomials. Using these transformations and the well_known Rogers_Ramanujan identities, we provide simple proofs of some identities of the Rogers_Ramanujan type.展开更多
基金Supported by National Natural Science Foundation of China (11871258)the Young Backbone Teachers in Henan Province (2020GGJS194)the Young Backbone Teachers in Luoyang Normal College (2019XJGGJS-10)。
基金supported by The National Natural Science Foundation (Grant Nos.41874126, 42004114)the Key Research and development project of Jiangxi Province in China (Grant No.20192ACB80006)+1 种基金the Natural Science Foundation of Jiangxi Province (Grant Nos. 20202BAB211010, 20212BAB203005)Open Foundation of State Key Laboratory of Nuclear Resources and Environment (2020NRE25)
文摘The quality factor Q is an important parameter because it can refl ect the reservoir attenuated features and can be used for inverse-Q filtering to compensate for the seismic wave energy.The accuracy of the Q estimation is greatly significant for improving the precision of the reservoir prediction and the resolution of seismic data.In this paper,the Q estimation formulas of the single-frequency point are derived on the basis of a diff erent-order Taylor series expansion of the amplitude attenuated factor.Moreover,the multifrequency point average(MFPA)method is introduced to obtain a stable Q estimation.The model tests demonstrate that the MFPA method is less aff ected by the frequency band,travel time diff erence,time window width,and noise interference than the logical spectrum ratio(LSR)method and the energy ratio(ER)method and has a higher Q estimation accuracy.In addition,the proposed method can be applied to post-stack seismic data and obtain eff ective Q values of complex models.When the MFPA method was applied to real marine seismic data,the Q values estimated by the MFPA method with the 1st–4th order showed good consistency with each other.In contrast,the Q values obtained by the ER method were larger than those of the proposed method,while those estimated by the LSR method signifi cantly deviated from the average values.In conclusion,the MFPA method has superior stability and practicability for the Q estimation.
文摘In this paper, we give two transformation formulas for q _series using two simple properties of q _ultraspherical polynomials. Using these transformations and the well_known Rogers_Ramanujan identities, we provide simple proofs of some identities of the Rogers_Ramanujan type.
