METHOD FOR THREE-DIMENSIONAL STRUCTURAL MAPPING OF FAULT ZONES AND STRESS FIELDS OF THE SEDIMENTARY COVER OF THE EARTH'S CRUST FOR HYDROCARBON DEPOSITS Russian patent published in 2023 - IPC G01V1/28 G01V1/30 

FIELD: geology.

SUBSTANCE: invention relates to petroleum and gas geology and seismic surveying, and can be used to identify and map fault zones and associated tectonic stress fields within hydrocarbon deposits with a complex structure of the sedimentary cover, due to the presence of faults and tectonic stresses in the rock mass being a controlling factor in the process of accumulation and distribution of hydrocarbon deposits and a complicating factor in the drilling of exploratory and production wells. In the implementation of the method, attributive analysis of the 3D seismic survey data is initially conducted by the common depth point method (3D CDP), isolating the fractures, with the statistical and spatial assessment of the array of tectonic fractures, mapping of the zone and block structure of the site, followed by the structural-paragenetic analysis of the local fracture networks applying reference parageneses and reconstruction of local stress fields and fault zones; then, rank-wise analysis of local solutions reaching the regional level with lower-order solutions; as a result, isolating the regional stages of development of the sedimentary cover within the hydrocarbon deposit and building a three-dimensional tectonophysical model thereof. The three-dimensional tectonophysical model of the sedimentary cover within the deposit includes: a fracture array, schemes of the fault and zone and block structure of the sedimentary cover, maps of local stress fields and orientations of small faults for the local volumes of the site, schemes of detailed spatial distribution of the regional stress fields in order of sequence of action thereof in the process of tectonic development. The method for three-dimensional structural mapping of fault zones and stress fields of the sedimentary cover of the Earth's crust for hydrocarbon deposits provides a solution to both fundamental and applied issues related to the development of deposits, in particular, allows for the location and identification of the morphogenetic type of fault zones, indirect assessment of the permeability of the rock mass and the points of possible drilling complications associated with high stresses and rock dislocation.

EFFECT: increase in the accuracy and informative value of structural mapping of fault zones and stress fields within complex hydrocarbon deposits, and thus, increase in the accuracy and level of detail of the assessment of the impact of faults and tectonic stresses on the conditions of borehole drilling and on the prediction of productivity of specific parts of the deposits.

1 cl, 4 dwg