摘要
勘探实践中时有在钻前被作为存在储层重要论据的地震强反射却在钻后被证实它来自大套泥岩之中,根本没有储层与之对应。研究认为,在一定沉积条件下,泥岩层间可以形成非常光滑的界面,这种界面虽然反射系数不大,但与砂泥岩层间比较粗糙的界面相比却具有极好的反射定向性,导致其反射的地震波能量基本不出现漫反射而可以集中地被检波器接收到,从而形成可与砂泥岩层间界面反射的强度相当的地震记录,因此在褶积公式中引入镜面系数就可以描述这种现象。勘探实践中认识大套泥岩中的这种反射,对于避免钻前储层预测的失误具有现实意义。
In petroleum exploration, the strong seis mic reflections that are considered as an important evidence of reservoirs before drilling may prove to be from massive mudrocks after drilling, with no reser voir corresponding to them. According to some re searches, very smooth interfaces may occur between the beds of mudrock under a certain sedimentary condition. With a not great reflectivity, these inter faces can generate excellent directional reflections in comparison with the rougher interfaces between sandstone beds and mudrock beds, and there is largely no diffuse reflection in the seismic energy refelcted by them, so that this seismic energy can be totally picked by the geophones, resulting in the strong seismic records comparable to those generated by the interfaces between sandstone beds and mudrock beds. Therefore, this phenomenon can described by introducing a mirror coefficient in the convolution formula. Identifying this type of seis mic reflection caused by massive mudrocks in ex- ploration is acturally helpful to avoiding the errors in reservoir prediction before drilling.
出处
《中国海上油气》
CAS
北大核心
2012年第A01期43-46,共4页
China Offshore Oil and Gas
关键词
镜面反射
地震强反射
镜面系数
大套泥岩
储层预测
褶积公式
mirror reflection seismic strong reflec tion
mirror coefficient
massive mudrock
reser voir prediction
convolution formula
