中國(guó)西部雙復(fù)雜探區(qū)典型三維正演模型的建立和正演模擬

關(guān)鍵詞：典型模型，前陸盆地，正演模擬，雙復(fù)雜探區(qū)，彈性介質(zhì)，黏彈介質(zhì)，各向異性 中圖分類號(hào)：P631 文獻(xiàn)標(biāo)識(shí)碼：A DOI：10.13810/j.cnki.issn.1000-7210.20250041

Abstract： The typical 3D numerical model and seismic simulation are of great significance for the study of seis mic processng and interpretation methods，as they can test and validate the efectiveness.of various new technologies and approaches. In the double-complex exploration areas in western China，where both neasurface and subsurface structures present significant complex，there have long been challnges of difficult seismic migration imaging and delineation of structures，making it urgent to build a typical 3D model and forward modeling data thatrepresent the double-complex characteristics of China’s foreland basins.By taking：the representative double-complex area of the Keshen block in the Kelasu area in western China as an example，this paper combines the typical surface and subsurface geological and geophysical features of foothillareas in the western foreland basins and fully utilizes data of seismic depth migration velocity，acoustic logging，VSP logging，and uphole survey to construct typical numerical models for double-complex exploration zones in western China（BGPDCGModels）. The BGP-DC2GModels include an acoustic velocity model，an isotropic elastic medium model， TTI/TORT models，and a viscoelastic medium model，typicall featuring complex near-surface conditions，complex subsurface structures，a：high-speed conglomerate fan body，salt-gypsum formations，detachment layers （coal seams），a Q anomaly，and anisotropy. Based on the BGP-DC2GModels，five sets of high-quality forward modeling data for surface and borehole 3D observation are generated by adopting the spectral-element method，

includig the isotropic acoustic wave，isotropic elastic wave，isotropic viscoelastic wave，TTI viscoelastic wave， and TORT viscoelastic wave. Additionally，the acoustic reverse time migration and anisotropic reverse time migrationresults of the data are compared and analyzed，further demonstrating that typical models and numerical simulation data can test and validate the effectiveness of new acquisition，processing，and interpretation methods.

Keywords：typical model，foreland basin，forward modeling，double-complex exploration area，elastic medium， viscoelastic medium，anisotropy

李培明，于海生，武威，等。中國(guó)西部雙復(fù)雜探區(qū)典型三維正演模型的建立和正演模擬[J].石油地球物理勘探， 2025，60（4） ：937-950.

LI Peiming，YU Haisheng，WU Wei，et al.Typical 3D forward model building and seismic simulation in dualcomplex exploration areas of western China[J]. Oil Geophysical Prospecting，2025，60（4）：937-950.

0 引言

地震正演模擬是通過(guò)數(shù)值或物理方法模擬地震波在地下介質(zhì)傳播的過(guò)程，對(duì)認(rèn)識(shí)地震波傳播規(guī)律、進(jìn)行地震屬性研究、驗(yàn)證地震資料地質(zhì)解釋、評(píng)價(jià)儲(chǔ)層等均具有重要的理論和實(shí)際意義[。因此，業(yè)界非常重視標(biāo)準(zhǔn)模型的建立和模型正演工作。國(guó)際上，SEG、EAGE學(xué)會(huì)以及BP等石油公司先后構(gòu)建了Sigsbee、Marmousi、三維鹽丘等一系列典型模型[2-3]。尤其是SEG組織的SEAM項(xiàng)目，從20O7年到2020年，歷時(shí)14年，建立了多種不同復(fù)雜地表、復(fù)雜構(gòu)造的典型數(shù)值模型，并形成了各向同性/各向異性（VTI/TTI/TORT（傾斜正交各向異性））/黏彈介質(zhì)的聲波、彈性波正演模擬數(shù)據(jù)。這些模型已成為國(guó)際上進(jìn)行地震方法研究的標(biāo)準(zhǔn)模型，被國(guó)內(nèi)外院校、企業(yè)的地球物理研究人員廣泛使用，每年利用這些模型的研究論文上萬(wàn)篇[4-5]。但這些地震一地質(zhì)模型大多針對(duì)墨西哥灣地區(qū)的地質(zhì)特點(diǎn)，其主要的地質(zhì)問(wèn)題是高速鹽丘及鹽下成像，勘探環(huán)境主要是海洋。雖然在SEAM項(xiàng)目II期中構(gòu)建了Arid、Foothill兩個(gè)相對(duì)復(fù)雜的陸上模型，但Arid模型聚焦中東沙漠環(huán)境特征，包括巖溶結(jié)構(gòu)以及松散的近地表沉積物；Foothill模型則是以南美洲Llanos盆地為基礎(chǔ)構(gòu)建的山前帶模型，側(cè)重于山區(qū)特征，包括陡峭地形和表面松軟的沖積扇，以及由褶皺和逆沖構(gòu)造構(gòu)成的深層復(fù)雜結(jié)構(gòu)[7-9]。……