有利砂体识别与解释

天然气的产量与砂岩的厚度，孔隙度，连通性，砂泥比等有密切的关系。为了解决砂体在空间以什么形态出现，其方向如何，纵向上如何变化，连通形式如何等问题，在前人研究的基础上，对篷来镇组某工区的砂体进行了精细识别和解释。在地震剖面上，砂体的响应一般表现为强振幅，低频率。孔隙性好，含气丰度高的砂体往往表现为速度低和极性反转的特点。但发现该工区的砂体在地震剖面上表现形式多变，甚至出现了合成地震记录与井旁地震记录严重不吻合的现象，故砂体识别工作不能遵循统一模式。因此，采用了多井约束，多层标定，分层解释来识别有利砂体。

Identification and Interpretation of Beneficial Sand

The output of natural gas is closely associated with thickness, porosity, connectivity of the sand and the ratio of sndToceth conformation, direction, changes and connectivity of sand in special, we have done subtle identification and interpretation of the sand in this field based on previous investigation and studies. The responses of sand in seismic profile usually are high amplitude and low frequency. The beneficial containing natural gas sand of high porosity and connectivity is characterized by low velocity and reversal polarity. But we found that the responses of sand in this field are divers, hestphnomenon of severe inconsistent between synthetic seismogram and the seismic records besides wells. Therefore we cannot identify the sand in this field by uniform mode. We have carried out this work by the way of constraining of many wells, standardizing with many formations and interpreting layer by layer on seismic synthetic records. The present paper introduces our sand identification and its interpretation methods in this field.