METHOD FOR DETECTING AND MONITORING THE DEVELOPMENT OF ZONES OF ABNORMALLY HIGH FORMATION PRESSURE IN THE UPPER PART OF THE SECTION OF BOTTOM SEDIMENTS ON WATER AREAS ACCORDING TO MULTIWAVE SEISMIC SURVEY DATA Russian patent published in 2025 - IPC G01V1/38 G01V1/28 G01V1/30 

FIELD: measuring.

SUBSTANCE: invention relates to seismic survey on water bodies and can be used to determine the position of formations with abnormally high fluid pressure during drilling and monitoring their development. A method is disclosed for detecting zones of abnormally high formation pressure (AHFP) in the upper part of a section of bottom sediments on water bodies based on multiwave seismic survey data, involving the following steps: A) bottom three-component seismic recorders are arranged at water area bottom; B) performing pressure waves excitation in water column by means of moving source, which creates direct waves, which are probing pulse; C) reading data on the components of the acceleration vector of the seabed, seismograms corresponding to each position of the source using said recorders; D) using the processing unit, selecting on the recorded seismograms a wave field corresponding to longitudinal and transverse reflected waves, determining the probing pulse forward polarity from the direct wave various components records and selecting the various types with the positive reflection coefficient reflected waves hodographs, which corresponds to probing pulse forward polarity, and negative reflection coefficient, which corresponds to probing pulse reverse polarity; E) using the processing unit, determining the dependence of the reflection coefficient for the selected hodographs of the reflected waves on the horizontal distance of the source-receiver; F) using the processing unit, identifying the following combinations of locus of reflected waves corresponding to the roof of the AHFP zone: longitudinal wave with a weakly varying negative reflection coefficient and a transverse wave with a positive reflection coefficient monotonously increasing from zero with the source and receiver matching horizontal positions; G) using the processing unit, identifying the following combinations of the locus of the reflected waves corresponding to the bottom of the AHFP zone: a longitudinal wave with a weakly varying positive reflection coefficient and transverse wave with negative reflection coefficient monotonically decreasing from zero at matching horizontal positions of source and receiver.

EFFECT: reliable detection of offshore AHFP zones.

3 cl, 1 dwg