Tectonic altitude determination method based on tectonic model in drilling layering design

Abstract

The invention discloses a tectonic altitude determination method based on a tectonic model in drilling layering design. The method comprises the following steps of: 1) determining a stratum frameworkon the basis of high-precision three-dimensional seismic data interpretation, establishing a well connecting time tectonic model of a target area and an existing well area, and directly obtaining wellpassing time values of the known well area and the target area; 2) determining the comprehensive average speed of the existing well area, and calculating the stratum speed; 3) according to the surrounding drilling condition, fitting the speed change trend of different stratums along with the increase of the burial depth; and (4) correspondingly endowing the interval velocity of the target area stratum according to the known well interval velocity and the structure model, correcting the interval velocity of the target area stratum according to the velocity change trend in the step (3), and finally calculating the required structure altitude in the drilling design stratification according to the well passing time value and the interval velocity. The stratum burial depth calculated through the method is more accurate, and the drilling risk caused by design errors is greatly reduced.

Description

technical field [0001] The invention relates to oil and gas exploration technology, in particular to a structure model-based structure elevation determination method in drilling layer design. Background technique [0002] In drilling design, the depth prediction of geological horizons is particularly important, especially for directional drilling in complex structural zones. Accurate horizon structure elevation is the key to drilling targets. In the stage of oil and gas exploration, there are few control wells in the area. During the process of drilling, due to the limited understanding of the data in the area, the geological logging layers are not typical, and it is difficult to judge the drilling layers accurately. It is difficult to achieve geological goals, and there will be greater engineering risks, which will further affect the progress and direction of exploration. How to avoid these risks, the key is to make good use of existing data to accurately calculate the str...

AI Technical Summary

Problems solved by technology

This method has some progress compared with the previous two methods, but the stacking speed is affected by the experience of the processing personnel, and it is difficult to ensure the accuracy of the speed picking in complex structures. Influenced by the sparsity of the network (similar to the second method), there will inevitably be certain errors, which are similar to the accuracy of direct mapping results using the pre-stack depth migration data interpretation results of well calibration, and the research time of this method is long and the work large amount

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