拓频处理技术在大牛地气田勘探开发中的应用
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摘要
大牛地气田储层具有低孔、低渗、非均质性强的特点,而且地表又为沙漠、半沙漠环境,煤层发育,煤层屏蔽现象严重,从而造成地震资料信噪比低、砂体的地震响应特征不明显,加大了储层预测的难度。因此,在该区采用了拓频处理技术进行地震资料处理。本文从拓频处理技术的原理入手,分析了拓频处理的特点,简要介绍了拓频处理流程中两个重要参数的选取,并通过在大牛地气田的实际应用,得到了明显效果,主要体现在:①主频提高、频带拓宽;②地震反射层位的地质意义更明确、地震信息更加丰富;③使合成记录与地震资料吻合率更高;④反映地震属性更精细。应用结果表明,该方法可以更好地为薄互储层反演、气藏描述提供可靠的基础资料。但建议该方法尽可能在信噪比高的地区使用,在大牛地气田,该方法更适合应用于山西组、太原组,对下石盒子组不大适用。
The reservoir in Daniudi gas field is characteristics of low porosity,low permeability and strong non-uniformity,and surface is covered by desert and semi-desert,developing coal seam that produces serious screen phenomenon,which resulted in low S/N ratio of seismic data and unclear feature of seismic response to sand body,making the reservoir prediction very difficult.For that reason,the frequency-broadening processing technique is used in seismic data processing in the region.Starting from the principle of frequency-broadening processing technique,the paper analyzed the feature of frequency-broadening processing,briefly introduced the selection of two important parameters in frequency-broadening processing flow.The method achieved significant result after practical application in Daniudi gas field,which is in the followings: ①improvement of dominant frequency and broadening the frequency band; ②the geologic meaning of horizons of seismic reflections is more meaningful and seismic information is more abundant; ③the match of synthetic seismogram with seismic data is better; ④the reflected seismic attributes are finer.The application results showed that the method can better provide the reliable basic data for inversion of thin and alternative reservoir and description of gas reservoir.The suggestion is that the usage of the method is better in the region where the S/N ratio is as high as possible.In the Daniudi gas field,the method is more suitable to Shanxi Formation and Taiyuan Formation and unsuitable to Lower Shihezi Formation.
The reservoir in Daniudi gas field is characteristics of low porosity,low permeability and strong non-uniformity,and surface is covered by desert and semi-desert,developing coal seam that produces serious screen phenomenon,which resulted in low S/N ratio of seismic data and unclear feature of seismic response to sand body,making the reservoir prediction very difficult.For that reason,the frequency-broadening processing technique is used in seismic data processing in the region.Starting from the principle of frequency-broadening processing technique,the paper analyzed the feature of frequency-broadening processing,briefly introduced the selection of two important parameters in frequency-broadening processing flow.The method achieved significant result after practical application in Daniudi gas field,which is in the followings: ①improvement of dominant frequency and broadening the frequency band; ②the geologic meaning of horizons of seismic reflections is more meaningful and seismic information is more abundant; ③the match of synthetic seismogram with seismic data is better; ④the reflected seismic attributes are finer.The application results showed that the method can better provide the reliable basic data for inversion of thin and alternative reservoir and description of gas reservoir.The suggestion is that the usage of the method is better in the region where the S/N ratio is as high as possible.In the Daniudi gas field,the method is more suitable to Shanxi Formation and Taiyuan Formation and unsuitable to Lower Shihezi Formation.
引文
[1]何自新等.鄂尔多斯盆地演化与油气.北京:石油工业出版社,2003
[2]徐衍和.优化高频拓展法在煤田勘探中的应用.中国煤田地质,2006
[2]徐衍和.优化高频拓展法在煤田勘探中的应用.中国煤田地质,2006