Calculating method and system of well-to-seismic integration average speed field

Abstract

The invention discloses a calculating method and system of a well-to-seismic integration average speed field. The method comprises the steps of: utilizing a well logging facies type of a target layer and a seismic facies type of the target layer to dividing a sedimentary facies of the target layer, encoding the sedimentary facies, and obtaining a sedimentary facies code; utilizing an earthquake to superpose speed fields, and by utilizing a Dix formula to calculate an earthquake average speed; utilizing well logging data to calculate a well logging average speed at each well drilling position of the target layer; and using the sedimentary facies code as a bound term, using the earthquake average speed as a secondary variable, using the well logging average speed as a main variable, utilizing a Co-Kriging estimating algorithm to carry out Co-Kriging interpolation, and obtaining a well-to-seismic integration average speed field. According to the invention, the high-precision well-to-seismic integration average speed field calculating method under the sedimentary facies constraint is utilized, and the consistence between a speed field transverse change trend and practical geological characteristics is ensured, so that the time-depth conversion precision of a structural map is improved.

Description

technical field [0001] The invention relates to the field of petroleum geophysical exploration, in particular to a calculation method and system for a combined well-seismic average velocity field. Background technique [0002] With the continuous improvement of oil and gas exploration, the geological conditions in the exploration area are becoming more and more complex. The problems of strong heterogeneity of underground media and large vertical and horizontal velocity changes pose challenges to high-precision velocity field modeling technology. At the same time, It also seriously affects the time-depth conversion accuracy of structural maps and other seismic interpretation results. The average velocity field is usually used in the time-depth conversion of structural maps, but most of the current average velocity field modeling methods are mainly based on seismic velocity conversion or logging velocity interpolation and extrapolation. Among them, the earthquake-based averag...

AI Technical Summary

Problems solved by technology

Obviously, the velocity field modeling method based on well logging data has the advantage of high longitudinal accuracy, but the lateral continuity of the established velocity field is often not reliable enough, and the logging data as "hard data" cannot Provide sufficient prior information, especially in fluvial reservoirs with complex structures and fast lateral changes, it is easy to generate structural artifacts by directly using logging data to interpolate and extrapolate the velocity field

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