垦东滩浅海地区地震勘探技术
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摘要
垦东滩浅海地区的环境特点给地震勘探带来很多难点,具体表现为:①地表条件变化大,地震激发、接收条件差,且易形成多个虚反射界面,引起多种干扰波,影响了地震资料的品质;②由于潮汐和海水的影响,检波器定位困难,影响资料处理精度;③受自然条件的影响,过渡带地震采集会存在多种观测方式,从而影响过渡带资料的无缝拼接;④在水域中采用气枪震源激发、水中压电检波器接收,在陆滩区采用炸药震源激发、沼泽压电检波器接收,造成地震波能量、频率和相位的较大差异。本文针对垦东滩浅海地区地震勘探的难点,形成了一套行之有效的滩浅海地震勘探技术,具体包括:①地震采集技术,包括表层结构调查技术、地震波激发技术、地震波接收技术、检波器精确定位技术、观测系统设计技术;②地震处理技术,包括差异校正技术、虚反射和变周期海底鸣震压制技术。通过滩浅海地震勘探技术在垦东滩浅海地区的应用,得到的资料无论在信噪比和分辨率方面都有所提高,并且实现了多种观测方式地震资料的无缝拼接。
The environmental characters of Kendong beach and shallow-sea area brings a lot of difficulties to seismic exploration, which are ①large variation of surface condition, poor shooting and receiving conditions and easy to form multiple ghost reflection interfaces, resulting in multiple interference waves and affecting the quality of seismic data; ②difficulty in geophone positioning because of influence of tide and sea-water, affecting data processing precision; ③multiple survey patterns may exists in seismic acquisition of transitional zone because of influence of natural conditions, affecting the seamless link of data in transitional zone; ④shooting by airgun and receiving by hydrophone in water area, and shooting by dynamite and receiving by swamp hydrophone in land area of beach, resulting in large difference in energy, frequency and phase of seismic waves. Due to the difficulties of seismic exploration in Kendong beach and shallow-sea area, the paper formed a set of feasible seismic exploration techniques in beach and shallow-sea area, including ①seismic acquisition technique, such as near-surface structure survey technique, seismic wave shooting and receiving techniques, precious geophone positioning technique and geometry designing technique; ②seismic data processing technique, such as bias correction technique, ghost and period-changing sea-bottom singing suppressed technique. The gained data have been greatly improved in both S/N ratio and resolution through application of this set of seismic exploration techniques in Kendong beach and shallow-sea area, and seamless link of seismic data with multiple geometry patterns has been realized.
The environmental characters of Kendong beach and shallow-sea area brings a lot of difficulties to seismic exploration, which are ①large variation of surface condition, poor shooting and receiving conditions and easy to form multiple ghost reflection interfaces, resulting in multiple interference waves and affecting the quality of seismic data; ②difficulty in geophone positioning because of influence of tide and sea-water, affecting data processing precision; ③multiple survey patterns may exists in seismic acquisition of transitional zone because of influence of natural conditions, affecting the seamless link of data in transitional zone; ④shooting by airgun and receiving by hydrophone in water area, and shooting by dynamite and receiving by swamp hydrophone in land area of beach, resulting in large difference in energy, frequency and phase of seismic waves. Due to the difficulties of seismic exploration in Kendong beach and shallow-sea area, the paper formed a set of feasible seismic exploration techniques in beach and shallow-sea area, including ①seismic acquisition technique, such as near-surface structure survey technique, seismic wave shooting and receiving techniques, precious geophone positioning technique and geometry designing technique; ②seismic data processing technique, such as bias correction technique, ghost and period-changing sea-bottom singing suppressed technique. The gained data have been greatly improved in both S/N ratio and resolution through application of this set of seismic exploration techniques in Kendong beach and shallow-sea area, and seamless link of seismic data with multiple geometry patterns has been realized.
引文
[1]李庆忠.走向精确勘探的道路.北京:石油工业出版社,1994
[2]吴三灵.实用振动试验技术.北京:兵器工业出版社,1993,46~47
[3]杨惊涛等.海上二次定位技术的研究与应用.石油物探,2002,41(增刊):67~69
[2]吴三灵.实用振动试验技术.北京:兵器工业出版社,1993,46~47
[3]杨惊涛等.海上二次定位技术的研究与应用.石油物探,2002,41(增刊):67~69
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