Abstract:Anomalous fluid pressure can cause special low velocity anomaly.The average velocity, interval velocity and RMS velocity of each layer can be obtained from seismic CDP data .They may be used to predict formation pressure and to calculate the specific gravity of drilling mud.The procedure to predict formation pressure is as follows: 1) velocity (or interval travel time Δt)versus depth at normal pressure is plotted, which is called normal trend curve of formation pressure variation, and is a straight line when logarithmic interval travel time Δt is used; 2) the velocity curve derived from actual interval velocities is compared with the normal trend curve of formation pressure variation; if a significant deviation from the normal curve appears, the deviating part indicates the position of overpressure zone.Here we must remove the possibility that the velocity anomaly is caused by lithologic change.The example shows practical the method of estimating formation pressure by seismic velocity.
引用本文:
卢贵和. 大港地区应用地震速度估算地层压力的效果[J]. 石油地球物理勘探, 1986, 21(2): 189-196.
Lu Guihe. The effect of estimating formation pressure using seismic velocity in Dagang area. OGP, 1986, 21(2): 189-196.