A pre-drilling depth prediction method based on vertical seismic data

Abstract

The invention provides a vertical seismic data based prespud depth predication method. The method includes acquiring stratum segment speed of a target layer by utilizing vertical seismic data of an adjacent well adjacent to a predication well; recognizing a reflection wave event corresponding to the target layer on a vertical seismic section of the predication well through combination of characteristics of seismic section wave groups of through-well ground of the predication well and reading top boundary reflection time of a target layer and bottom boundary reflection time of the target layer;according to the top boundary reflection time of the target layer and the bottom boundary reflection time of the target layer, calculating a stratum reflection time difference of the target layer; utilizing the stratum reflection time difference of the target layer and the stratum segment speed of the target layer, calculating the predication depth of the target layer. The invention can predicatethe depth of the target layer quickly and accurately and provides effective and reliable data support for drilling engineering.

Description

technical field [0001] The invention belongs to the field of geophysical signal interpretation, and relates to a pre-drilling depth prediction method based on vertical seismic data, which is mainly applied to the pre-drilling target layer depth prediction in drilling engineering. Background technique [0002] Pre-drilling depth prediction is a very important task for drilling engineering. Pre-drilling depth prediction using vertical seismic data is a traditional geophysical exploration technology. It is an important geophysical means to obtain information about the target layer ahead of the drill bit. appeared at birth. [0003] The pre-drilling depth prediction technology using vertical seismic data is to vertically put the geophone deep into the well, and record the up and down seismic waves at the same time, so as to realize the pre-drilling depth prediction by using the vertical seismic information. There are two commonly used methods at present. One is to intersect th...

AI Technical Summary

Problems solved by technology

There are two commonly used methods at present. One is to intersect the first arrival extension of the P-wave with the same phase axis of the target layer. The depth of the intersection point is the predicted depth. The disadvantage is that when the formation velocity changes greatly, the prediction accuracy will be affected. The other is to use the vertical seismic inversion to invert the pre-drilling formation velocity and predict the depth in combination with the time of the target layer. However, due to the strong multi-solution of the inversion results, there are certain uncertainties in the prediction results

Images