瞬时子波吸收分析技术在复杂地区的应用——以吐哈盆地鄯勒地区为例
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摘要
由于储层孔隙中充满了气体,地震波高频能量将会很快衰减(气体介质纵波衰减速度相当快),因此,地震波传播过程中高频能量衰减规律可应用于储层含气性检测。为了确保提取地震信息的准确性,首先对地震资料进行高分辨率、高信噪比和高保真处理,并在此基础上进行了基于子波能量的吸收分析,求取能时变、空变地震子波,再求取瞬时子波能量衰减的垂向分布规律,消除强反射的干扰,以便在叠后资料中准确分析出含气储层的吸收异常。指出吐哈盆地鄯勒地区E sh气储层为砂砾岩,J2x2油储层之下发育多套特殊地层——煤层,这些层位在地震剖面上均表现为强反射,在瞬时子波吸收剖面上表现为强吸收,这样储层含油气引起的强吸收与煤层的强吸收混在了一起,但由于受油气引起的强吸收的影响,煤层的强吸收在含油气段发生了一定的变化,使得含气层、含油层和含煤层的强吸收仍存在差异,例如E sh层含气部位强吸收存在时窗往上漂移,位置高于砂砾岩地层的地震同相轴,J2x2油层的强吸收较煤层的强吸收弱,故可以通过这种差异来识别油气层。
The high frequency of seismic waves will attenuate quickly when the porous reservoir is permeated by gas(P-wave attenuates at great speed in the gas medium).Accordingly,the attenuation regularities of the high frequency of traveling seismic can be used for gas reservoirs detection.To get exact seismic information,seismic data should be processed to get high resolution,high S/N and high fidelity.Based on the processed seismic data,we apply the wavelet-based energy absorbing analysis to calculate time varying and space varying wavelets,and then calculate the vertical distribution of the energy attenuation of instantaneous wavelets,according to which the noise will be eliminated.Finally,the absorption abnormity of the gas reservoir can be analyzed with accuracy using the post stack data.The dominating oil and gas strata in the Shanle area is joined to special strata vertically,the Esh reservoir is glutenite and there are several coal layers under J_2x2.Both strata appear as strong absorption in the absorption section of instantaneous wavelets.The strong absorption caused by the oil and gas bearing strata is mixed with that by special strata,but the oil and gas strata can be recognized by their differences.The strong absorption of the gas bearing part of Esh shifts upwards in time direction,resulting in its higher position than the event of the glutinite strata.The strong absorption of J_2x2 is weaker than that of coal layer, showing the existence of oil and gas.
The high frequency of seismic waves will attenuate quickly when the porous reservoir is permeated by gas(P-wave attenuates at great speed in the gas medium).Accordingly,the attenuation regularities of the high frequency of traveling seismic can be used for gas reservoirs detection.To get exact seismic information,seismic data should be processed to get high resolution,high S/N and high fidelity.Based on the processed seismic data,we apply the wavelet-based energy absorbing analysis to calculate time varying and space varying wavelets,and then calculate the vertical distribution of the energy attenuation of instantaneous wavelets,according to which the noise will be eliminated.Finally,the absorption abnormity of the gas reservoir can be analyzed with accuracy using the post stack data.The dominating oil and gas strata in the Shanle area is joined to special strata vertically,the Esh reservoir is glutenite and there are several coal layers under J_2x2.Both strata appear as strong absorption in the absorption section of instantaneous wavelets.The strong absorption caused by the oil and gas bearing strata is mixed with that by special strata,but the oil and gas strata can be recognized by their differences.The strong absorption of the gas bearing part of Esh shifts upwards in time direction,resulting in its higher position than the event of the glutinite strata.The strong absorption of J_2x2 is weaker than that of coal layer, showing the existence of oil and gas.
引文
[1]袁明生,梁世君,燕列灿,等.吐哈盆地油气地质与勘探实践[M].北京:石油工业出版社,2002.
[2]黄凯,杨晓海,徐群洲,等.岩石弹性参数实验室模拟测试与AVO碳烃检测[J].新疆石油地质,1997,6(2):119-124.
[3]黄凯,徐群洲,杨晓海,等.地震波能量的衰减及其影响因素[J].新疆石油地质,1997,9(3):212-216.
[4]彭路平,李在光,曹正林.应用地球物理综合技术预测盐湖沉积的含油性[J].石油勘探与开发,2001,28(3):5-7.
[5]李在光,杨占龙,郭精义,等.吐哈盆地台北凹陷葡北东斜坡含油性检测[J].新疆石油地质,2005,26(3):269-271.
[6]李在光,杨占龙,李琳,等.胜北地区油气分布规律[J].天然气地球科学,2006,17(1):94-97.
[7]张虎权,于均民,李在光,等.气藏综合描述技术在吐哈盆地鄯勒地区第三系浅层气藏描述中的应用[J].天然气地球科学,2004,15(1):62-67.
[2]黄凯,杨晓海,徐群洲,等.岩石弹性参数实验室模拟测试与AVO碳烃检测[J].新疆石油地质,1997,6(2):119-124.
[3]黄凯,徐群洲,杨晓海,等.地震波能量的衰减及其影响因素[J].新疆石油地质,1997,9(3):212-216.
[4]彭路平,李在光,曹正林.应用地球物理综合技术预测盐湖沉积的含油性[J].石油勘探与开发,2001,28(3):5-7.
[5]李在光,杨占龙,郭精义,等.吐哈盆地台北凹陷葡北东斜坡含油性检测[J].新疆石油地质,2005,26(3):269-271.
[6]李在光,杨占龙,李琳,等.胜北地区油气分布规律[J].天然气地球科学,2006,17(1):94-97.
[7]张虎权,于均民,李在光,等.气藏综合描述技术在吐哈盆地鄯勒地区第三系浅层气藏描述中的应用[J].天然气地球科学,2004,15(1):62-67.
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