基于各向异性高分辨地震处理的煤层顶板含水性风险评价  

Evaluation of coal seam roof water-bearing risk area via anisotropic high-resolution seismic processing

作　　者：李慧婷 常锁亮 张生 刘波 赵兴 余攀 LI Huiting;CHANG Suoliang;ZHANG Sheng;LIU Bo;ZHAO Xing;YU Pan(Department of Geosciences and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Shanxi Shandi Geophysical ProspectingTechnology Co.,Ltd.,Jinzhong 030600,China)

机构地区：[1]太原理工大学地球科学与工程系,山西太原030024 [2]山地物探技术有限公司,山西晋中030600

出　　处：《煤炭科学技术》2024年第S01期192-200,共9页Coal Science and Technology

基　　金：国家自然科学基金资助项目(42102212);山西省揭榜挂帅资助项目(20191101018,20201101004)。

摘　　要：随着矿井水防治在煤矿开采中的重要性与日俱增,对地震精细勘探的方法也提出了更高要求,常规基于各向同性的地震勘探已无法满足对复杂条件下煤层及其顶底板的高精度勘探要求。根据煤系地层正交各向异性特征,综合其周期性薄互层各向异性和裂隙诱导型各向异性,针对具有垂直对称轴的横向各向同性(Transverse Isotropy Medium with Vertical Symmetry Axis,VTI)介质特性提出基于高阶动校正的广角成像方法拉平同相轴,提高远、近偏移动校正精度,针对方位各向异性(Trans-verse Isotropy with Horizontal Axis of Symmetry,HTI)介质特性应用炮检距向量片(Offset Vector Tile,OVT)域处理消除煤系地层构造裂隙下不同方位各向异性,在地震资料处理阶段提高成像精度及分辨率。在宽方位高保真成像基础上,岩性解释基于岩石物理特征的拟声波方法,通过对声波时差测井曲线进行重构,在速度曲线中融入地层岩性信息,通过反演迭代可分析地层岩性空间展布特征;裂隙解释基于OVT道集所包含的方位角偏移距信息椭圆拟合,得到地震波在不同方位衰减梯度,由方位衰减梯度数据拟合得到裂缝密度及方位推出地层裂缝密度分布特征,实现对影响矿井水灾两大关键参数煤层顶板含水层以及导水裂隙带的精细探查。在此基础上对煤层顶板产水危险区进行综合评估。将所提方法应用于研究区,实际资料含水风险评价与生产井情况吻合度较好,结果验证了所提出的风险评价方法的可行性及适用性,为煤层开采中矿井水灾危险区预测提供了有益参考。With the increasing importance of mine water prevention and control in coal mining,higher requirements have been put for-ward for precise seismic exploration methods.Conventional seismic exploration based on isotropy is increasingly unable to meet the high-precision exploration requirements for coal seams and their roof and floor under complex conditions.Based on the orthogonal anisotropy characteristics of coal bearing strata,the periodic thin interlayer anisotropy and fracture induced anisotropy are comprehensively con-sidered.A wide-angle imaging method based on high-order motion correction is proposed to flatten the in-phase axis and improve the ac-curacy of far and near offset motion correction for the characteristics of the transverse isoropy medium with vertical symmetry axis(VTI).Applying the Offset Vector Tile(OVT)domain processing to eliminate anisotropy in different directions under structural fractures in coal bearing strata,in response to the characteristics of the transverse isoropy with horizontal axis ofs symmetry medium(HTI).Improve ima-ging accuracy and resolution during seismic data processing.Improve imaging accuracy and resolution during the seismic data processing phase.On the basis of wide azimuth and high fidelity imaging,lithology interpretation is based on the pseudo acoustic method of rock physical characteristics.By reconstructing the acoustic time difference logging curve and incorporating formation lithology information in-to the velocity curve,the spatial distribution characteristics of formation lithology can be analyzed through inversion iteration.Fracture in-terpretation is based on ellipse fitting of azimuth offset information contained in OVT gathers to obtain attenuation gradient of seismic wave in different azimuth,and fracture density and azimuth are fitted to obtain distribution characteristics of formation fracture density.To achieve precise exploration of the two key parameters affecting mine flooding,the coal seam roof aquifer and the water conducting frac-ture zone.On t

关 键 词：正交各向异性介质 OVT处理 顶底板岩性 裂隙系统 含水性评价 

分 类 号：P631.4[天文地球—地质矿产勘探] TD745[天文地球—地质学]