洛带气田蓬莱镇组气层地震反射特征及横向预测

GAS ZONE SEISMIC REFLECTION CHARACTER OF PENGLAIZHEN FORMATION OF LUODAI GAS FIELD IN SICHUAN BASIN AND PREDICTION OF ITS LATERAL DISTRIBUTION

洛带气田为构造控制下的岩性气藏 ,储集岩主要为上侏罗统蓬莱镇组砂泥岩互层沉积中的砂岩 ,它具有厚度薄、层速度低的特点。在地震反射剖面上表现为波谷波峰相随、振幅较强的特点 ,气层层速度越低 ,则其反射波的振幅越强。利用气层地震反射特征结合已知钻井进行气层横向预测 ,取得了较好的实际效果。

Luodai gas field is lithologic gas trap controlled by structure. The reservoir, dominated by sandstones within sand shale interbeds in Penglaizhen Formation of Upper Jurassic, is very thin in thickness and very low in seismic horizon velocity. From Seismic reflection profile, the reservoir is characterized by complex waves association and strong amplitude. The lower the gas zone horizone velocity is, the stronger the reflection amptitude appears. Using the gas zone seismic reflection character incorporated with drilled wells to predict its lateral distribution, we have obtained better predicting effects.