临清坳陷西部任县凸起基底电性结构研究及地热开发建议
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摘要
河北省任县地区地热资源具有储量丰富、埋深适宜、开发潜力大等优点。本文应用大地电磁测深法(MT法)对临清坳陷西部任县凸起深部地层结构进行探测研究,共布设了5条MT剖面,获得了216个测深点。通过对大地电磁测深点的处理及反演,获得了任县周边区域4km以浅电性结构模型。阻抗张量分解结果表明任县凸起浅部一维特征明显,深部二维特征增强,主构造方向以近南北向为主。任县凸起4km以浅电性结构差异明显,从浅到深电阻率逐渐升高,具有纵向分层结构,据此将研究区地层从上到下划分为第四系、第三系、石炭系-二叠系、寒武系-奥陶系,并勾画出各层顶、底面起伏情况。结合区域地质资料,认为任县地区地热开发有利区域位于研究区南东侧,目的层位以基岩裂隙岩溶热储为佳。
Geothermal resources in Renxian area of Hebei Province have the advantages of abundant reserves, suitable burial depth and great potential for development. In this paper, magnetotelluric sounding(MT) method is applied to detect and study the deep stratum structure of Renxian uplift in western Linqing depression. Five MT profiles are laid out and 216 sounding points are obtained. Through processing and inversion of MT points, a shallow electrical structure model of 4km in the surrounding area of Renxian County is obtained. The results of impedance tensor decomposition show that the shallow part of Renxian uplift has obvious one-dimensional characteristics, while the deep part has enhanced two-dimensional characteristics.The main structural direction is nearly north-south. Renxian uplift has obvious difference in shallow electrical structure with increasing resistivity from shallow to deep, and has a vertical stratified structure. According to this, the strata in the study area are divided into four layers: Quaternary, Neogene, Carboniferous-Permian and Cambrian-Ordovician, and the top and bottom undulations of each layer are delineated. Combining with regional geological data, it is considered that the favorable geothermal development area in Renxian is located on the southeastern side of the study area, and the target horizon is the bedrock fissure karst thermal reservoir.
Geothermal resources in Renxian area of Hebei Province have the advantages of abundant reserves, suitable burial depth and great potential for development. In this paper, magnetotelluric sounding(MT) method is applied to detect and study the deep stratum structure of Renxian uplift in western Linqing depression. Five MT profiles are laid out and 216 sounding points are obtained. Through processing and inversion of MT points, a shallow electrical structure model of 4km in the surrounding area of Renxian County is obtained. The results of impedance tensor decomposition show that the shallow part of Renxian uplift has obvious one-dimensional characteristics, while the deep part has enhanced two-dimensional characteristics.The main structural direction is nearly north-south. Renxian uplift has obvious difference in shallow electrical structure with increasing resistivity from shallow to deep, and has a vertical stratified structure. According to this, the strata in the study area are divided into four layers: Quaternary, Neogene, Carboniferous-Permian and Cambrian-Ordovician, and the top and bottom undulations of each layer are delineated. Combining with regional geological data, it is considered that the favorable geothermal development area in Renxian is located on the southeastern side of the study area, and the target horizon is the bedrock fissure karst thermal reservoir.
引文
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霍光谱,胡祥云,黄一凡,等,2015.带地形的大地电磁各向异性二维模拟及实例对比分析[J].地球物理学报,58(12):4696-4708.
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吕大炜,赵洪刚,李增学,等,2012.渤海湾盆地临清坳陷晚古生代古地理特征[J].古地理学报,14(4):437-450.
吕希学,2006.渤海湾盆地临清坳陷东部热演化历史和成烃史[J].地质科学,(4):676-687.
徐守余,严科,2005.渤海湾盆地构造体系与油气分布[J].地质力学学报,(3):259-265.
周建勋,周建生,2006.渤海湾盆地新生代构造变形机制:物理模拟和讨论[J].中国科学.D辑:地球科学,(6):507-519.
Bahr K,1991. Geological noise in magnetotelluric data:a classification of distortion types[J]. Physics of the Earth and Planetary Interiors,66(1-2):24-38.
Caldwell T G, Bibby H M, Brown C,2004. The magnetotelluric phase tensor[J]. Geophysical Journal International, 158(2):457-469.
Groom R W, Bailey R C,1989. Decomposition of magnetotelluric impedance tensors in the presence of local three-dimensional galvanic distortion[J]. Journal of Geophysical Research,94(B2):1913-1925.
Rodi W, Mackie R L,2001.Nonlinear conjugate gradients algorithm for2-D magnetotelluric inversion[J]. Geophysics,(1):174-187.
Swift C M, 1967. A magnetotelluric investigation of an electrical conductivity anomaly in the southwestern United States[D].Cambridge:Massachusetts Institute ofTechnology.
河北省地质矿产局,1996.河北省岩石地层[M].武汉:中国地质大学出版社.
河北省环境地质勘察院,2003.邢台市地热资源调查评价报告[R].
霍光谱,胡祥云,黄一凡,等,2015.带地形的大地电磁各向异性二维模拟及实例对比分析[J].地球物理学报,58(12):4696-4708.
姜慧超,张勇,任凤楼,等,2008.济阳、临清坳陷及鲁西地区中新生代构造演化对比分析[J].中国地质,(5):963-974.
李焱,胡祥云,吴桂桔,等,2010.基于MPI的二维大地电磁正演的并行计算[J].地震地质,32(3):392-401.
吕大炜,赵洪刚,李增学,等,2012.渤海湾盆地临清坳陷晚古生代古地理特征[J].古地理学报,14(4):437-450.
吕希学,2006.渤海湾盆地临清坳陷东部热演化历史和成烃史[J].地质科学,(4):676-687.
徐守余,严科,2005.渤海湾盆地构造体系与油气分布[J].地质力学学报,(3):259-265.
周建勋,周建生,2006.渤海湾盆地新生代构造变形机制:物理模拟和讨论[J].中国科学.D辑:地球科学,(6):507-519.
Bahr K,1991. Geological noise in magnetotelluric data:a classification of distortion types[J]. Physics of the Earth and Planetary Interiors,66(1-2):24-38.
Caldwell T G, Bibby H M, Brown C,2004. The magnetotelluric phase tensor[J]. Geophysical Journal International, 158(2):457-469.
Groom R W, Bailey R C,1989. Decomposition of magnetotelluric impedance tensors in the presence of local three-dimensional galvanic distortion[J]. Journal of Geophysical Research,94(B2):1913-1925.
Rodi W, Mackie R L,2001.Nonlinear conjugate gradients algorithm for2-D magnetotelluric inversion[J]. Geophysics,(1):174-187.
Swift C M, 1967. A magnetotelluric investigation of an electrical conductivity anomaly in the southwestern United States[D].Cambridge:Massachusetts Institute ofTechnology.