井-地观测系统(3D+VSP)和基于模型的处理技术有关问题的讨论

Discussion of 3D-VSP acquisition geometry and model-based processing in seismic exploration

对了解地下构造和描绘地下油气分布来说,用地面地震勘探技术可以分辩15～30 m的地层.低分辨率和缺乏详细的速度信息会降低地面地震勘探的效果,在研究更薄细的油气储层和研究已研究过的老区时,我们要采用一些更先进的勘探技术,对储层进行更精确的预测和描绘.本文分析了VSP、测井和地面地震勘探各自的优势、不足和局限,采用VSP方法,我们只能得到井周围一定空间内的丰富速度信息,而详细的速度模型可以极大地提高地面地震勘探的效果.据此分析,组合VSP和地面地震方法优势的井-地观测系统（3D＋VSP）,可有效地增加信息量,并可通过引入VSP数据处理时所用的基于模型的处理技术,来使井-地观测系统的优势进一步扩大,在此基础上,如果与精细测井相结合,可以更好的寻找和开发剩余油气,这将是我们今后重要的发展方向.

Up to date 3D seismic exploration on the surface （SES） provides reliable images as well as estimations of productive layer structure and distribution of oil and gas in underground media with resolution of 15～30 m. Low resolution and absence of detailed velocity models limit efficiency of SES. The new technique is necessary for more detailed description of productive layers while finding and extracting the residual oil deposits. In this paper resolution ability, special feature and limitations of VSP, LOG and SES are analyzed. VSP is estimated to be fundamentally limited in investigating near-borehole space. Higher efficiency of SES cannot be achieved unless a more detailed and reliable velocity model is available. It is proposed to combine advantages of VSP and SES with 3D acquisition geometry （3D＋ VSP）. The advantages of this technology may be amplified with application of model-based iterative vector pro- cessing approach developed in VSP. If we combine this with fine well logging, better result will be achieved in finding and extracting the residual oil deposits. It will be the important direction of development.