亮点、暗点与油气的关系

在陆相沉积地层中,砂岩含油气后可能形成亮点,也可能形成暗点,关键在于砂、泥岩之间的速度差或砂岩含油气后与泥岩的速度差。文中指出,当砂、泥岩速度差大于600m/s或砂岩含油气后速度差大于400m/s时可形成亮点;当砂岩不含油时的速度与泥岩速度差小于400m/s或砂岩含油、气后与泥岩的速度差小于300m/s时可形成暗点。在亮点剖面解释中,借助反射系数量板对判别砂岩含油气后应该是亮点还是暗点,极性的正负,具有重要的意义。文中在分析前人利用亮点技术检测油气成败的基础上,提出了亮点剖面的一些解释方法和应用实例。

The relationship between bright spot,dim spot,and oil or gas

Hydrocarbon-bearing sand bed in continental sedimentary series can create bright spot or dim spot,this depends on the velocity difference between net sand bed and shale,or the velocity difference between hydrocarbon-bearing sand bed and shale.The bright spot occurs when the velocity difference between net sand bed and shale is higher than 600m/s,or when the velocity difference between hydrocarbon-bearing sand bed and shale is higher than 400m/s.Dim spot comes to the seismic record when the velocity difference between net sand bed and shale is less than 400m/s,or when the velocity difference between hydrocarbon-bearing sand bed and shale is lower than 300m/s.In the interpretation of bright-spot section,the use of reflection coefficient template is very significant in determining whether the hydrocarbon-bearing sand bed will cause bright spot or dim spot,and whether the reflection is positive-polar or negative-polar.On the basis of analysing the people's success and failure in past oil-gas detection with the use of bright spot technique,the paper puts forward some interpretation methods for bright spot section and presents the interpretation examples.