基于OBC地震资料的叠后叠前多尺度裂缝预测技术在涠西南潜山储层中的应用

Application of post-and-pre-stack multi-scale fracture prediction technology based on OBC seismic data in the reservoir of Weixinan buried hill

涠西南潜山储层具有较大资源潜力,但常规基于单一叠后地震属性的裂缝预测精度尚无法满足精细目标评价需求。笔者基于OBC地震资料宽方位数据优势,在叠后属性大尺度裂缝预测中利用相干、曲率和似然等多属性进行融合以提高裂缝预测可靠性,并进一步提出基于多方位预测融合法和法向照明数据优选预测法,分别通过多方位划分和法向照明实现数据基础改善,从而提高裂缝预测精度;在叠前裂缝预测中,开展道集优化处理并基于AVAZ计算各向异性强度等表征中尺度裂缝密度与方向;最后利用成像测井获得小尺度裂缝发育认识,并最终形成了基于OBC地震资料的叠后叠前多尺度裂缝预测技术,取得了较好的应用成效。

The reservoir of Weixinan buried hill has excellent resource potential,but the accuracy of conventional fracture prediction methods based on single post-stack seismic attribute cannot meet the needs of precise target evaluation.Based on the advantage of wide azimuth data in OBC seismic data,the article utilizes multiple attributes such as coherence,curvature,and likelihood to improve the reliability of crack prediction in post-stack attribute large-scale crack prediction.Furthermore,a fusion method based on multi-azimuth prediction and a data optimization prediction method based on normal illumination are proposed.The data foundation is improved through multi-azimuth division and normal illumination,respectively,to improve the accuracy of crack prediction.In pre-stack crack prediction,gather optimization processing is conducted to calculate anisotropic strength based on AVAZ,which leads to the density and direction of mesoscale cracks.Finally,the understanding of small-scale fracture development was obtained through drilling imaging,and a post-and-pre-stack multi-scale fracture prediction technology based on OBC seismic data is ultimately formed,achieving good application results.