针对四川盆地龙门山推覆构造复杂地质目标的地震采集技术
|
摘要
近年在四川盆地西北部龙门山山前隐伏带钻探的多口井在二叠系获得了高产工业气流,但是该区块的地表地形起伏剧烈,出露地层复杂,涉及石灰岩、砂泥岩、砾岩、河滩砾石等多种岩性,激发接收条件差,且地腹地质结构复杂,断裂发育、地层倾角大,甚至直立倒转,导致有效地震波能量极弱,地震波成像效果差,难以获得目的层的有效反射,无法满足油气勘探需求。为获得更好的地震采集资料,特别是推覆构造带的中、深层地震信息,针对该区块开展了地震采集攻关,采用高覆盖三维观测设计、激发及接收条件优选、过障碍动态观测系统设计等技术措施,保证了目的层有效波覆盖次数,提高了采集单炮的信噪比,改善了复杂构造成像效果,整体上剖面成像效果得到大幅提升。
In the piedmont buried belt of Longmenshan Mountain, northwestern Sichuan Basin, high-yield industrial gas flow has been obtained from the Permian in some wells. This block, however, is featured by salient surface topographic relief, complex exposure strata which are composed of limestone, sand shale, conglomerate, and bench gravel, bringing about poor exciting and receiving conditions. In addition, with complex structure and developed faults, the belly in this block is characterized by high stratigraphic dip even vertical reversal, resulting in weaker energy of seismic wave and poorer imaging effect of seismic wave. It's very hard to achieve the effective reflection of the target and to meet the exploration demand. So, Many acquisition technologies and measures, including high-coverage 3D survey design, exciting-and receiving-condition optimization, and dynamic obstacle-crossing geometry design, were studied and made in order to acquire better seismic data especially on middle to deep layers of Longmengshan nappe belt. These technologies and measures may ensure the coverage frequency of effective wave in the target, increase the signal-to-noise ratio of single-shot acquisition, perfect the imaging effect of complex structure, and greatly improve the imaging effect of section.
In the piedmont buried belt of Longmenshan Mountain, northwestern Sichuan Basin, high-yield industrial gas flow has been obtained from the Permian in some wells. This block, however, is featured by salient surface topographic relief, complex exposure strata which are composed of limestone, sand shale, conglomerate, and bench gravel, bringing about poor exciting and receiving conditions. In addition, with complex structure and developed faults, the belly in this block is characterized by high stratigraphic dip even vertical reversal, resulting in weaker energy of seismic wave and poorer imaging effect of seismic wave. It's very hard to achieve the effective reflection of the target and to meet the exploration demand. So, Many acquisition technologies and measures, including high-coverage 3D survey design, exciting-and receiving-condition optimization, and dynamic obstacle-crossing geometry design, were studied and made in order to acquire better seismic data especially on middle to deep layers of Longmengshan nappe belt. These technologies and measures may ensure the coverage frequency of effective wave in the target, increase the signal-to-noise ratio of single-shot acquisition, perfect the imaging effect of complex structure, and greatly improve the imaging effect of section.
引文
[1]林茂炳,吴山.龙门山推覆构造变形特征[J].成都地质学院学报,1991,18(1):46-54.Lin Maobing&Wu Shan.Deformational features of nappe structures in the Longmenshan mountains[J].Journal of Chengdu College of Geology,1991,18(1):46-54.
[2]刘和甫,梁慧社,蔡立国,沈飞.川西龙门山冲断系构造样式与前陆盆地演化[J].地质学报,1994,68(2):100-117.Liu Hefu,Liang Huishe,Cai Liguo&Shen Fei.Structural styles of the Longmenshan thrust belt and evolution of the foreland basin in western Sichuan province,China[J].Acta Geologica Sinica,1994,68(2):100-117.
[3]贾秋鹏,贾东,朱艾斓,陈竹新,胡潜伟,罗良,等.青藏高原东缘龙门山冲断带与四川盆地的现今构造表现:数字地形和地震活动证据[J].地质科学,2007,42(1):31-44.Jia Qiupeng,Jia Dong Zhu Ailan,Chen Zhuxin,Hu Qianwei,Luo Liang,et al.Active tectonics in the Longmen thrust belt to the eastern Qinghai-Tibetan plateau and Sichuan Basin:Evidence from topography and seismicity[J].Chinese Journal of Geology,2007,42(1):31-44.
[4]刘树根,罗志立,戴苏兰,Arne D,Wilson CJL.龙门山冲断带的隆升和川西前陆盆地的沉降[J].地质学报,1995,69(3):205-214.Liu Shugen,Luo Zhili,Dai Sulan,Arne D&Wilson CJL.The uplift of the Longmenshan thrust belt and subsidence of the western Sichuan foreland basin[J].Acta Geologica Sinica,1995,69(3):205-214.
[5]贾东,陈竹新,贾承造,魏国齐,李本亮,张惬,等.龙门山前陆褶皱冲断带构造解析与川西前陆盆地的发育[J].高校地质学报,2003,9(3):402-410.Jia Dong,Chen Zhuxin,Jia Chengzao,Wei Guoqi,Li Benliang,Zhang Qie,et al.Structural features of the Longmen shan fold and thrust belt and development of the western Sichuan Foreland Basin,central China[J].Geological Journal of China Universities,2003,9(3):402-410.
[6]黄有晖,朱运红,蔡明,段孟川,张德刚,张立超,等.实时质量监控技术在复杂山地三维地震采集中的应用[J].天然气勘探与开发,2015,38(2):31-34.Huang Youhui,Zhu Yunhong,Cai Ming,Duan Mengchuan,Zhang Degang,Zhang Lichao,et al.Application of real-time quality control technology to 3D seismic acquisition in complex mountains[J].Natural Gas Exploration&Development,2015,38(2):31-34.
[7]宋桂桥,于世焕.山前带地震勘探技术进展与对策研究[J].石油物探,2012,51(6):539-547.Song Guiqiao&Yu Shihuan.Progress and strategy of the seismic exploration in foothill area[J].Geophysical Prospecting for Petroleum,2012,51(6):539-547.
[8]丁成明,康家光,钱光萍.探索龙门山前缘物探采集技术[J].中外能源,2006,11(1):30-33.Ding Chengming,Kang Jiaguang,Qian Guangping.Study on seismic data acquisition for the frontal region of Longmen mountain[J].China Foreign Energy,2006,11(1):30-33.
[2]刘和甫,梁慧社,蔡立国,沈飞.川西龙门山冲断系构造样式与前陆盆地演化[J].地质学报,1994,68(2):100-117.Liu Hefu,Liang Huishe,Cai Liguo&Shen Fei.Structural styles of the Longmenshan thrust belt and evolution of the foreland basin in western Sichuan province,China[J].Acta Geologica Sinica,1994,68(2):100-117.
[3]贾秋鹏,贾东,朱艾斓,陈竹新,胡潜伟,罗良,等.青藏高原东缘龙门山冲断带与四川盆地的现今构造表现:数字地形和地震活动证据[J].地质科学,2007,42(1):31-44.Jia Qiupeng,Jia Dong Zhu Ailan,Chen Zhuxin,Hu Qianwei,Luo Liang,et al.Active tectonics in the Longmen thrust belt to the eastern Qinghai-Tibetan plateau and Sichuan Basin:Evidence from topography and seismicity[J].Chinese Journal of Geology,2007,42(1):31-44.
[4]刘树根,罗志立,戴苏兰,Arne D,Wilson CJL.龙门山冲断带的隆升和川西前陆盆地的沉降[J].地质学报,1995,69(3):205-214.Liu Shugen,Luo Zhili,Dai Sulan,Arne D&Wilson CJL.The uplift of the Longmenshan thrust belt and subsidence of the western Sichuan foreland basin[J].Acta Geologica Sinica,1995,69(3):205-214.
[5]贾东,陈竹新,贾承造,魏国齐,李本亮,张惬,等.龙门山前陆褶皱冲断带构造解析与川西前陆盆地的发育[J].高校地质学报,2003,9(3):402-410.Jia Dong,Chen Zhuxin,Jia Chengzao,Wei Guoqi,Li Benliang,Zhang Qie,et al.Structural features of the Longmen shan fold and thrust belt and development of the western Sichuan Foreland Basin,central China[J].Geological Journal of China Universities,2003,9(3):402-410.
[6]黄有晖,朱运红,蔡明,段孟川,张德刚,张立超,等.实时质量监控技术在复杂山地三维地震采集中的应用[J].天然气勘探与开发,2015,38(2):31-34.Huang Youhui,Zhu Yunhong,Cai Ming,Duan Mengchuan,Zhang Degang,Zhang Lichao,et al.Application of real-time quality control technology to 3D seismic acquisition in complex mountains[J].Natural Gas Exploration&Development,2015,38(2):31-34.
[7]宋桂桥,于世焕.山前带地震勘探技术进展与对策研究[J].石油物探,2012,51(6):539-547.Song Guiqiao&Yu Shihuan.Progress and strategy of the seismic exploration in foothill area[J].Geophysical Prospecting for Petroleum,2012,51(6):539-547.
[8]丁成明,康家光,钱光萍.探索龙门山前缘物探采集技术[J].中外能源,2006,11(1):30-33.Ding Chengming,Kang Jiaguang,Qian Guangping.Study on seismic data acquisition for the frontal region of Longmen mountain[J].China Foreign Energy,2006,11(1):30-33.