摘要

地震属性与所预测对象之间的关系复杂,不同工区和不同储层对所预测对象敏感的地震属性是不完全相同的.即使在同一工区、同一储层,预测对象不同对应的敏感地震属性也是有差异的,地震属性优化技术是解决此问题的有效途径.运用降维映射、属性选择和聚类、交会分析等地震属性优化方法,优化出了预测储层的地震属性,并运用正演模型技术,对优选出的地震属性之一波峰数进行了验证,说明了优化方法的可靠性.在此基础上,对CB331井区进行了储层预测,新描述砂体30多个,预测石油地质储量4000×104t.

A seismic attributes includes physical attribute and geometry attribute, which quantifies specifically the characters of geometry, kinematics, dynamics or statistics in seismic data. Although geometry attributes can be easily accepted and straightly identified by the sense organ of men,the physical attributes derived from abstract process and mathematics are better than geometry attribute in seismic reservoir prediction.Therefore,seismic attribute is mainly referred to physical attribute calculated by mathematical algorithm. Reservoir prediction by seismic attributes is widely used in geophysics. Since 1980s,pattern recognition technique is paid great attention to,and the reservoir prediction techniques,such as a fuzzy pattern recognition, statistic pattern recognition, neural network pattern recognition and function approach,have been successively developed.The predicted objects include hydrocarbon, reservoir thickness, lithology and reservoir porosity.In resevoir prediction,the selection of seismic attribute is accomplished by experiences of interpreters,whose effect is subject to better geological conditions, simple predicted objects,and higher S/N in original seismic data. However, under the other conditions, the effect of prediction is worse. In fact,there exist complex relations between predicted objects and their seismic attributes. The seismic attributes sensitive to predicted objects are not totally the same in different areas and reservoirs. They are also somewhat different even for same reservoir and same area. The optimization technique of seismic attributes is an effective means for solving the above questions. The optimum methods of seismic attributes mainly include the dimension-reduced projected profile and cluster analysis etc. Its purpose is to optimize the minimum seismic attributes or seismic attributes group, which are the most sensitive (or most effective, most representative) to studied problem,in order to increase reservoirs prediction precision and to improve the effect of processing an