应用多分量资料减少解释陷阱

P波资料在浅层小断层的分辨能力,弱阻抗界面、气云影响深层界面以及储层内部构造细节等方面的成像能力有一定的局限性。在这种情况下采用PS波资料,能够得到地层的真实成像．取得很好的地质效果,在煤田、ZY油田以及国外多分量资料中有许多成功的例证。对于不同储层类型的油气藏,无论P波振幅表现为“亮点”还是“暗点”,增加PS波的信息,可以避免在单一P波资料上油气异常指示的解释风险,这可从AnadarkO盆地和北海Sleipner油田的多分量资料中得到充分的印证。在利用地震资料进行地层裂缝检测时,由于地震波的振幅或速度变化受多种因素控制,如几何扩散、吸收衰减、薄层调谐等,而裂缝地层对S波产生的分裂现象是惟一的。因此,利用地震资料进行裂缝检测和提取裂缝参数,最可靠的资料还是S波或PS波资料。当P波剖面上出现平点时,通过对PS波资料的解释可以确定是油水界面还是岩性变化引起的异常,Grane油田多分量资料的解释显示出良好的流体识别效果。

Reduction of interpretation pitfalls using multicompenent data

P-wave has limitations in imaging weak impedance interfaces and gas cloud zones as well as resolving shallow minor faults and internal detailed features of a reservoir.In such cases real images of layers can be achieved by using PS-wave data. Examples of successful application of multicomponent data were found in many coal fields and ZY oilfield. and were also reported by foreign researchers.Whether P-wave amplitude appears as "bright spot" or "dim spot" in different reservoirs, integrating PS-wave information into data interpretation helps reduce risks in recognizing oil & gas indicators in pure P-wave data. This conclusion has been confirmed by the application of multicomponent data in Anadarko basin and Sleipner field. Changes of amplitude or velocity are controlled by many factors such as geometric dispersion,attenuation,and thintuning,and wave splitting is unique to S-wave.therefore, the most reliable seismic data for detection of fractures are S-waves and PS-waves. Flat spots on P-wave sections can further be classified as oil-water-contact-related or lithological-related with PS wave data Multicompenent data has been successfully applied to infer possible hydrocarbon occurrences in Grane field.