A structural model-based structural elevation determination method in drilling layer design

Abstract

The invention discloses a method for determining structural elevation based on structural models in drilling layered design, comprising the following steps: 1) determining the stratum frame on the basis of high-precision three-dimensional seismic data interpretation, and establishing the relationship between the target area and the existing well area Well-connected time structure model, and directly obtain the well-passing time value of the known well area and the target area; 2) Determine the comprehensive average velocity of the existing well area, and calculate the formation velocity; 3) According to the surrounding drilling conditions, fit the The velocity change trend of different formations with the increase of buried depth; 4) According to the known well formation velocity, the formation velocity of the target formation is correspondingly given by the structural model, and the formation velocity of the target formation is corrected according to the velocity variation trend of step 3), and finally according to the Well time values ​​and layer velocities calculate the required structural elevations in the well design layering. The formation depth calculated by the method of the invention 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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