AVO技术在固安地区浅层天然气藏的有效检测
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摘要
固安地区是华北油田的勘探老区,勘探难度越来越大。但近年通过引进多种新技术,探井成功率得到明显提高。AVO技术是气藏直接检测的重要技术手段,尤其对于浅层高孔隙砂岩检测效果更为明显。文章就AVO技术在固安浅层气勘探的成功应用进行了详细阐述,通过对地震属性和AVO正反演分析,证实固安地区浅层气藏具有明显的亮点和III类AVO特征。在此基础上,在应用振幅属性、AVO反演、AVO弹性波反演等多种技术手段的同时,对含气敏感的多种属性进行综合分析,预测了固安地区浅层气分布特征。实钻结果证实了上述方法的有效性,形成了一套针对固安浅层气层勘探配套技术和思路。
Gu'an area is an old exploration area of Huabei Oilfield, where exploration becomes more and more difficult. However, the success rate of exploration well has been remarkably improved in recent years thanks to introduction of various new technologies. AVO technology is an important technological method for direct inspection of gas reservoirs. The result is more obvious when used to inspect shallow high-porosity sandstone. The article makes an detailed elaboration about successful application of AVO technology for shallow natural gas exploration in Gu'an area. Based on analysis of seismic attributes and AVO forward and inversion, it is confirmed that shallow gas reservoirs in Gu'an area have bright points and AVO characteristics of Ⅲ type. Various technological methods, such as amplitude attributes, AVO inversion, and AVO elastic wave inversion, are used to analyze gas-sensitive attributes and predict the distribution characteristics of shallow gas in Gu'an area. The actual drilling results confirmed effectiveness of the above-stated methods, leading to a set of technology and mindset appropriate for exploration of shallow gas in Gu'an area.
Gu'an area is an old exploration area of Huabei Oilfield, where exploration becomes more and more difficult. However, the success rate of exploration well has been remarkably improved in recent years thanks to introduction of various new technologies. AVO technology is an important technological method for direct inspection of gas reservoirs. The result is more obvious when used to inspect shallow high-porosity sandstone. The article makes an detailed elaboration about successful application of AVO technology for shallow natural gas exploration in Gu'an area. Based on analysis of seismic attributes and AVO forward and inversion, it is confirmed that shallow gas reservoirs in Gu'an area have bright points and AVO characteristics of Ⅲ type. Various technological methods, such as amplitude attributes, AVO inversion, and AVO elastic wave inversion, are used to analyze gas-sensitive attributes and predict the distribution characteristics of shallow gas in Gu'an area. The actual drilling results confirmed effectiveness of the above-stated methods, leading to a set of technology and mindset appropriate for exploration of shallow gas in Gu'an area.
引文
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[2]Rutherford S R,Williams R H.Amplitude-versus-offset in gas sands.Geophysics,1989,54:680～688.
[3]Ross C P,Kinman D L.Nonbright-spot AVO:Two examples.Geophysics,1995,60:1398～1408.
[4]Castagna J P,Swan H W,Principles of AVO Cross Plotting.The Leading Edge,1997,6,Issue4:337～344.
[5]Greenberg M L,Castagna J P.Shear-wave velocity estimation in porous rocks.Theoretical formulation,preliminary verification and applications.Geophys.Prosp.1992,40:195～210.
[2]Rutherford S R,Williams R H.Amplitude-versus-offset in gas sands.Geophysics,1989,54:680～688.
[3]Ross C P,Kinman D L.Nonbright-spot AVO:Two examples.Geophysics,1995,60:1398～1408.
[4]Castagna J P,Swan H W,Principles of AVO Cross Plotting.The Leading Edge,1997,6,Issue4:337～344.
[5]Greenberg M L,Castagna J P.Shear-wave velocity estimation in porous rocks.Theoretical formulation,preliminary verification and applications.Geophys.Prosp.1992,40:195～210.
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