摘要
随着找矿工作向寻找盲矿与深部隐伏矿方向发展,传统金属矿勘查技术已不能完全满足深部资源勘查要求。在一定条件下,地震勘探方法能凭借其探测深度大、分辨率高等特点,突破传统非地震勘探方法的瓶颈,发挥其潜力与优势。基于金属矿地震勘探的复杂性,目前金属矿地震勘探研究尚属初步探索阶段,通过对金属矿地震数值模拟研究,可以提高我们对金属矿介质中地震波传播规律的认识,指导观测系统设计,验证地震地质解释准确性等。
本文在分析研究地震波基本理论的基础上,由一阶速度-应力弹性波方程和声波方程出发,采用高阶交错网格技术对时间与空间导数进行差分近似,推导并建立了方程的差分格式,通过控制差分方程稳定性条件,并在边界加载PML吸收边界条件,实现了对简单不均匀体、透镜体、倾斜体、组合体以及火山口矿体等模型的正演计算。经数值模拟得到了相应介质模型的地震波场记录、声波场记录以及自激自收地震剖面,并对其波场特征进行分析。
通过数值模拟与效果分析可以看出,采用时间二阶空间十阶差分格式,控制稳定性条件,加载PML吸收边界条件,可达到较高的计算精度,能较好的模拟地震波在金属矿介质中的传播。对模拟的地震波场特征分析发现,地震波在几何特征复杂的金属矿体中,容易产生散射、绕射、波的转换等,各种波相互干涉叠加,地震波场复杂。
As the development of exploring blind mine and deeply concealed mine, Traditional exploring methods of metal mine can not fully meet the requirements of deeply exploration. Under certain conditions, Because of large exploring depth and high resolution features of seismic exploration,It can breaks defects of traditional non-seismic exploration methods,and refects their potentials and advantages. Based on complexity of metal mine, seismic exploration method of metal mine currently still stay in the initial stage, through seismic numerical simulation of exploring metal mines, can enhance understangding seismic wave of moving in metal media, improve surseying system, and verify the accuracy of seismic geological interpretation.
Based on the analysis of seismic wave theory, from one order velocity-stress elastic wave equation and acoustic equation, the using of high order and staggered grids in time and space derivative of the difference approximation is derived,and the difference schemes of elastic wave equation and acoustic equation are established, space of grids and time sampling rate are controlled,PML conditions of absorbing boundary is added, and completing modelling metal mine typical models included simple heterogeneous,lens,tilt body,portfolio body,crater ore body. By the forward calculation of seismic waves,We can get seismic records of elastic wave and acoustic, seismic profile of self-percussion and self-receicing, and have a analysis of wave field.
According to seismic numerical simulation and analysis in effect in using two orders in time and ten orders in space staggered finite-difference technique to simulate seismic waves in the metal mine,and controlling the condition of stablity, and adding PML absorbing boundary, we can achieve a good result of accuracy and modelling seismic wave which moving in metal media. We analyze the characteristics of seismic wave field, and find that seismic wave of metal mine media can scatter, diffraction, transform and mutually superpostion, the siesmic wave field is often complex.
引文
[1]徐明才,高景华,柴铭涛,等.金属矿地震勘探[M],北京：地质出版社,2009.7
[2]徐明才,高景华,柴铭涛,等.寻找隐伏金属矿的地震[J].勘探地球物理进展,2007,30(1)：16-24
[3]周平,施俊法.金属矿地震勘查方法评述[J].地球科学进展,2008,23(2)：120-128
[4]勾丽敏,刘学伟,雷鹏,等.金属矿地震勘探技术方法研究综述-金属矿地震勘探技术及其现状[J].勘探地球物理进展,2007,30(1)：16-24
[5]张永刚.地震波场数值模拟方法[J],石油物探,2003,42(2)：143-148
[6]刘洋,魏修成.复杂构造中地震波传播数值模拟[J],新疆石油地质,2008,29(1)：012-014
[7]高景华,徐明才,荣立新,等.小热泉子铜矿区地震方法技术试验[J].地质与勘探,2004：40(6)
[8]PretoriusC C,Trewick W F,Fourie A, et al.. Application of 3-D seismics to mine planning at Vaal Reefs gold mine,number 10 shaft,Republic of south Africa[J]. Geophysics,2000,65(6):1862-1870.
[9]White D,Boerner D,Wu jianjun,et al.Mineral exploration in the Thompson nickel belt,manitoba,Canada,using sismic and controlled-source EM methods[J]. Geophysics,2000,65(6):1871-1881
[10]SalisburyMH, MilkereitB, AscoughG, etal. Physical properties and seismic imaging of massive sulfides[J]. GeoPhysics,2000,65(6):1882-1889
[11]Milkereit B,Berrer E K,King,Alan R,Watts et al.Application of 3-D seismic exploration technology for deep nickelcooper deposits-A case histroy from the sudbury basin,Canada.Geophysics[J],2000,65(6):1890-1899.
[12]SalisburyM H, MilkereitB, BleekerW. Seismic imaging of massive sulfid deposits:Partl, Rock properties. Economic Geology[J],1996,92(5):822-528
[13]EatonD W, MilkereitB, SalisburyMH.seismic methods for deep mineral exPloration:Mature technologies adapted to new targets[J].The Leading Edge, 2003,22(6):580-585
[14]王炳章.地震岩石物理学及其应用研究[D].成都理工大学博士学位论文,2008.
[15]Birch F.The velocity of compressional waves in rocks to 10 kilobars,Part Journal of Geophyssics Researeh[J],1960,65(4):1083-1102
[16]Birch F.The veloeity of compressional waves in rocks to 10 kilobars, Part, our journal of Geophyssies Researeh[J],1961,66(13):2199-2224
[17]SalisburyM H, HarveyC W, Matthews 1. The acoustic Properties of ores and host rocks in hardrock terranes. In:EatonDW, MilkereitB, In:EatonD W,Milkereit B, SalisburyM H eds. Hardrock Seismic Exploration.Tulsa:society of Exploration Geophysicists[J],2003.9-19
[18]勾丽敏,刘学伟,雷鹏,等.金属矿地震勘探技术方法研究综述-散射波地震勘探[J].勘探地球物理进展,2007,30(2)：86-90
[19]Wu R-S,Aki K.1985.Scattering characteristics of elastic waves by an elastic heterogeity[J]. Geophysics,1985,50(4):582-595.
[20]Eaton D W. Weak elastic-wave seattering from massive sulfide orebodies[J]. Geophysies,1999,64(1):289-299
[21]EatonD W, Clarke G. A Kichhoff integral method to model 3-D elastic-wave scattering[J].Expanded Abstracts of the 70th Annual Internat SEG Meeting,2000, 1-4
[22]孙明,林君.金属矿地震散射波场的数值模拟研究[J],地质与勘探,2001,37(4)：68-70
[23]尹军杰,地震散射波场特征的数值模拟研究[D].中国地质大学(北京)博士学位论文,2005
[24]李灿萍.散射波特征与非均匀地质体对应关系研究[D].中国地质大学(北京)博士学位论文,2006
[25]李灿苹,刘学伟,王祥春,等.地震的散射理论和散射特征及其应用[J].地球物理学进展,2004,28(2)：81-89
[26]李灿萍,刘学伟,李颖,等.随机均匀介质散射波特征相干分析研究[J],地球物理学进展,2009,24(4)：1392-1398
[27]勾丽敏,散射波成像处理技术研究[D].中国地质大学(北京)博士学位论文,2007
[28].田丽花,地震波散射正演数值模拟[D],中国地质大学(北京)硕士论文,2007
[29]佘德平.波场数值模拟技术[J],勘探地球物理进展,2004,27(1)：016-021
[30]张文波.井间地震交错网格高阶差分数值模拟及逆时偏移成像研究[D],长安大学博士学位论文,2006
[31]马德堂.弹性波场数值模拟及井间地震初至波旅行时层析成像[D],长安大学博士学位论文,2006
[32]冯英杰,杨长春,吴萍.地震波有限差分模拟综述[J],地球物理学进展, 2007,22(2)：487-491
[33]韩翀,地震波数值模拟与波场特征分析[D],成都理工大学硕士论文,2007
[34]朱军,二维地震正演模拟方法技术研究[D],长安大学硕士学位论文,2007
[35]王春燕,高阶交错网格有限差分地震波场计算[D],成都理工大学硕士学位论文,2007
[36]常君勇,交错网格有限差分法地震数值模拟[D],中国地质大学(北京)硕士学位论文,2007
[37]左莹,基于高阶交错网格的有限差分地震波场数值模拟[D],长安大学硕士学位论文,2009
[38]杨旭明,裴正林.复杂近地表弹性波波场特征研究[J],石油地球物理勘探,2007,42(6)：658-664
[39]戈革.地震波动力学基础[M].北京：石油工业出版社,1980,239-245
[40]何樵登.地震波理论与方法[M].长春：吉林大学出版社,2005,188-189
[41]孙成禹.地震波理论与方法[M].东营：中国石油大学出版社,2007.7
[42]熊章强,周竹生,张大洲.地震勘探[M].长沙：中南大学出版社,2010.9
[43]王祥春,刘学伟.起伏地表二维声波方程地震波场模拟与分析[J],石油地球物理勘探,2007,42(3)：268-276
[44]李芳,孙建国,王雪秋,等.2.5维声波数值模拟[J],吉林大学学报地球科学版,2006,36,增刊：177-181
[45]熊章强,方根显.浅层地震勘探[M].北京：地震出版社,2002.4
[46]王勇,朱亚平,杨慧珠.共散射点成像及其在低信噪比三维地震数据处理中的应用[J],石油地球物理勘探,2000,35(1)
[47]姚姚.地震波场与地震勘探[M].北京：地质出版社,2006.6
[48]陈伟.起伏地表条件下的二维地震波场的数值模拟[J].勘探地球物理进展,2005,28(1)：025-031
[49]熊晓军,贺振华,黄德济.复杂地表条件下的地震波场模拟方法研究[J].西安石油大学学报(自然科学版),2006,21(6)：005-007
[50]孙卫涛.弹性波动方程的有限差分数值解法[M].北京：清华大学出版社,2009.2
[51]董良国,马在田,曹景忠,等.一阶弹性波方程交错网格高阶差分解法[J],地球物理学报,2000,43(3)：411-419
[52]董良国,马在田,曹景忠.一阶弹性波方程交错网格高阶差分解法稳定性研究[J],地球物理学报,2000,43(6)：856-864
[53]董良国.复杂地表条件下地震波传播数值模拟[J],勘探地球物理进展,2005, 28(3)：187-194
[54]熊章强,唐圣松,张大洲.瑞雷面波数值模拟中的PML吸收边界条件[J],物探与化探,2009,33(4)：453-457
[55]高景华.金属矿勘查中的地震理论模型研究[J],物探与化探,2002,26(5)：350-356