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  本文選題：反Q濾波　切入點：穩(wěn)定性控制　出處：《東北石油大學》2017年碩士論文　論文類型：學位論文

【摘要】：由于實際地球介質(zhì)存在粘性吸收,地球介質(zhì)的小尺度非均勻也產(chǎn)生類似于粘性吸收的幅值衰減效應(yīng),這些客觀存在導(dǎo)致了地震波在傳播過程中發(fā)生幅值的吸收衰減,而在油田勘探、開發(fā)的中后期,提高對深層薄砂體、薄互層、微幅構(gòu)造等隱蔽油氣藏的勘探能力,增強對小斷層、裂縫發(fā)育帶等油氣疏導(dǎo)體系的識別能力,進而識別有利的油氣儲層,是目前地震勘探的主要目標。這就需要針對粘性介質(zhì)吸收與頻散進行有效補償和校正。其中反Q濾波就是一種目前常用的補償方法。常規(guī)的反Q濾波方法一般基于波場延拓理論,具有不穩(wěn)定性或振幅補償不足的缺點,補償高頻能量的同時也不可避免地增強了高頻噪聲,出現(xiàn)不穩(wěn)定現(xiàn)象,且通常的時不變增益限約束的反Q濾波振幅補償雖可控制地震資料信噪比,但其經(jīng)常會壓制深層地震波的高頻成分,降低深層地震資料的分辨率。因此,本文針對上述兩個問題,在前人研究的基礎(chǔ)上,提出了二次函數(shù)法、三角函數(shù)法2種新的穩(wěn)定性控制方法,設(shè)計了兩種新的反Q濾波補償算子。并利用理論合成數(shù)據(jù)模型驗證期有效性,并與穩(wěn)定因子法對比分析,分析結(jié)果表明:2種新的穩(wěn)定性控制方法均可以有效增強反Q濾波過程中的穩(wěn)定性,并且相比于穩(wěn)定因子法具有更強的振幅恢復(fù)效果,更加明顯的改善深層的分辨率。以這兩種穩(wěn)定性方法為基礎(chǔ),將自適應(yīng)增益限的思想與穩(wěn)定性控制方法結(jié)合,使優(yōu)化的振幅補償函數(shù)的增益限自適應(yīng)于地震數(shù)據(jù)有效頻帶的截止頻率,通過理論模型試驗,分析其時域及頻域補償效果,深層補償效果明顯提升,驗證了其有效性。由于薄層調(diào)諧等現(xiàn)象存在,基于反射地震資料確定Q值則變的更加困難,因此,在以上研究的基礎(chǔ)上,本文還對克服薄層調(diào)諧現(xiàn)象的Q值建模方法進行研究,提出一套基于頻率導(dǎo)數(shù)的算術(shù)平均值來剔除薄層調(diào)諧效應(yīng)的影響,利用Q值掃描來判斷頻率恢復(fù)狀況,從而實現(xiàn)用反射資料估計等效Q值的方法;通過改變以往從地震衰減數(shù)據(jù)出發(fā)求取疊加Q值的思想,提出了先對地震數(shù)據(jù)進行粘性補償,將地震波損失的能量進行補償,使補償后的數(shù)據(jù)展現(xiàn)出沒有粘性衰減特征。消除地震數(shù)據(jù)經(jīng)過一定的傳播距離后,幅值過低而受到背景噪聲和多次波等因素的影響。算法實質(zhì)就是選取正確的疊加Q值使深、淺地層子波的頻譜譜寬保持一致。并將這種Q值建模方法應(yīng)用與理論模型和實際地震資料處理中,充分驗證了其可實用性。
[Abstract]:Due to the existence of viscous absorption in the actual earth medium, the small scale nonuniformity of the earth medium also produces amplitude attenuation effects similar to the viscous absorption, which leads to the absorption and attenuation of the seismic wave in the process of propagation. In the middle and late stages of oil field exploration and development, the ability to explore subtle reservoirs, such as deep thin sand bodies, thin interbeds, micro-structures, and so on, is improved, and the ability to identify oil and gas dredging systems such as small faults and fracture development zones is enhanced. In order to identify favorable oil and gas reservoirs, It is necessary to compensate and correct the absorption and dispersion of viscous media effectively. The inverse Q filter is one of the commonly used compensation methods. Yu Bo's field extension theory, It has the disadvantage of instability or insufficient amplitude compensation. The compensation of high frequency energy inevitably increases the high frequency noise and instabilities. The amplitude compensation of inverse Q filter with time-invariant gain limit can control the signal-to-noise ratio of seismic data, but it often suppresses the high frequency component of deep seismic wave and reduces the resolution of deep seismic data. In this paper, two new stability control methods, quadratic function method and trigonometric function method, are proposed on the basis of previous studies. Two new inverse Q filter compensation operators are designed, and the validity of the period is verified by the theoretical synthesis data model, and compared with the stability factor method. The analysis results show that the two new stability control methods can effectively enhance the stability in the inverse Q filter process, and have a stronger amplitude recovery effect than the stability factor method. Based on these two stability methods, the idea of adaptive gain limit is combined with the stability control method. The gain limit of the optimized amplitude compensation function is adapted to the cutoff frequency of the effective frequency band of seismic data. Through theoretical model test, the compensation effect in time domain and frequency domain is analyzed, and the deep compensation effect is improved obviously. Because of the phenomenon of thin layer tuning, it is more difficult to determine Q value based on reflection seismic data. Therefore, based on the above research, the Q value modeling method to overcome thin layer tuning phenomenon is also studied in this paper. A set of arithmetic average method based on frequency derivative is proposed to eliminate the influence of thin layer tuning effect, and the frequency recovery condition is judged by Q value scan, so that the equivalent Q value can be estimated by reflection data. By changing the idea of calculating the stack Q value from seismic attenuation data in the past, the viscous compensation of seismic data is put forward, and the energy loss of seismic wave is compensated. The compensated data show that there is no viscous attenuation, and the amplitude of seismic data is too low after a certain propagation distance, which is influenced by background noise and multiple waves. The algorithm is essentially to select the correct superposition Q value to make the seismic data deep. The spectral width of wavelet in shallow strata is consistent, and its practicability is fully verified by applying this Q value modeling method to theoretical model and practical seismic data processing.
【學位授予單位】：東北石油大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：P631.4

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本文編號：1598048