煤矿采空区四维地震特征分析及识别方法:以淮南煤田张集矿区为例  

4D Seismic Characteristics in Coal Mine Gobs:A Case Study from the Zhangji Coal Mine in Huainan Coalfield

作　　者：苑昊 刘佳朋 姜在兴[1] YUAN Hao;LIU Jiapeng;JIANG Zaixing(School of Energy Resources,China University of Geosciences,Beijing 100083,China;School of Geophysics and Information Technology,China University of Geosciences,Bejing 100083,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]中国地质大学(北京)地球物理与信息技术学院,北京100083

出　　处：《现代地质》2021年第4期1018-1023,共6页Geoscience

基　　金：“十三五”国家科技重大专项(2017ZX05009-002);国家自然科学基金项目(41772090,41974157)。

摘　　要：煤矿采空区塌陷是一个重要的地质问题,由于采空塌陷区地震、地质条件的复杂性,传统三维地震勘探探测方法难以准确查明采空区边界。本研究提出一种基于四维地震特征的煤矿采空区识别方法,并以淮南煤田张集煤矿为靶区开展采空区探测。该方法从模型驱动入手,通过建立煤层开采前、后地质模型及进行正演模拟,利用模型地震叠前时间偏移剖面回溯分析采空区引起的地震特征差异。根据模型数据采空区的地震反射特征,指导识别实际地震数据中的采空区,并通过地震解释圈定采空区范围。张集煤矿的实际四维地震数据分析结果显示,采空区域反射波连续性变差,采空区边界出现同相轴错断现象;因此,利用采空区四维地震特征差异能够有效识别煤矿采空区,并能准确圈定采空区的范围。Gob subsidence is an important geological problem in coal mines,and can seriously impact coal production and represent a potentially-lethal safety risk.Therefore,detection of gob subsidence is important to ensure sustainable coal mining.Due to the complex seismic and geological conditions in the gob subsidence area,it is hard to identify accurately the gob boundary with conventional three-dimensional(3D)seismic explo-ration methods.Therefore,we propose a new,model-driven gob identification method based on four-dimension-al(4D)seismic characteristics,and use the Zhangji coal mine in the Huainan coalfield as an example.In this method:(1)geological models before and after coal seam mining are established and forward modeling is per-formed;(2)the prestack time migration(PSTM)sections of the synthetic seismic data are used to back-analyze the seismic features of the gobs,which are identified according to the seismic feature variations caused by the gobs;(3)the seismic features of the gob areas(in synthetic seismic data)are used to guide the gob identification in real seismic data;(4)through seismic interpretations,the gob areal extent is constrained.Analysis of the real 4D seismic data from Zhangji coal mining area shows that the continuity of the gob reflection decreases,and the reflection is displaced at the gob boundary.Therefore,this detection method(based on the 4D seismic difference)can effectively detect the gobs and delineate their boundary.

关 键 词：采空区 四维地震 正演模拟 淮南煤田 

分 类 号：P618.11[天文地球—矿床学] P631.4[天文地球—地质学]