Well logging curve standardization method and system based on sedimentary facies constraint

Abstract

The invention discloses a well logging curve standardization method and system based on sedimentary facies constraint. The method comprises the steps: determining a standard layer of a work area stratum, and selecting a standard well from each phase zone of the standard layer according to an analysis result of sedimentary facies; according to the well logging curve of the standard well in each phase zone, acquiring the corresponding well logging curve correction value in each phase zone; correcting the well logging curve of the standard well in each phase zone according to the corresponding well logging curve correction value to obtain a corrected well logging curve of the standard well; for the logging curve of the target well in each phase zone, and performing standardizing according tothe corresponding corrected logging curve of the standard well to obtain a standardized logging curve of the target well. According to the method, based on the actual data, the method achieves the standardizing of the logging curve split-phase zones in a work area, reasonably keeps differences between the phase zones, takes a target layer sand body as a standard layer to carry out logging curve standardization, eliminates the longitudinal non-geological factor errors, and provide reliable logging data for seismic inversion.

Description

technical field [0001] The invention relates to the field of seismic reservoir prediction, and more specifically, to a logging curve standardization method and system based on sedimentary facies constraints. Background technique [0002] Well logging data contains rich subsurface information, which is an important basic data for seismic inversion and directly affects the accuracy of inversion results. However, due to the influence of wellbore environment, measurement time, instrument calibration, human operation and other factors, the logging energy between wells is unbalanced, which makes the logging data vary greatly in the lateral direction and destroys the lateral continuity of the inversion results. The log standardization is the method to correct this error. [0003] There are many common methods of logging curve standardization, such as histogram method, mean value correction method, trend surface method and so on. Usually, the mudstone section deposited stably in o...

AI Technical Summary

Problems solved by technology

However, in actual work, in some work areas, the lateral variation of the sedimentary facies is large, and the wells in different positions of the work area are in different sedimentary facies, so it is impossible to find the standard layer with the same sedimentary facies and stable deposition that exists in all wells in the whole area.

In addition, there are also differences in the vertical errors of individual wells. After the standard layer mudstone section is corrected, the relative errors of other intervals may not be completely avoided.

This makes the standardization of conventional logging curves limited, and may even bring results that do not conform to geological laws, and cannot meet the accuracy of reservoir prediction

Especially for work areas with relatively large lateral changes in sand bodies, if only a certain well is selected as a standard well, the standardized logging curve cannot truly reflect the underground change trend, resulting in unsatisfactory reservoir prediction results

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