METHOD FOR LOCALIZING RESERVES OF FRACTURED SILICEOUS RESERVOIRS Russian patent published in 2024 - IPC G01V11/00 

FIELD: oil industry.

SUBSTANCE: used in geological exploration in terms of assessing hydrocarbon reserves of oil deposits in unconventional reservoirs of oil source siliceous deposits. A method is proposed for localizing reserves of fractured siliceous reservoirs, in which an interwell correlation is carried out based on geophysical well logging data (GIS) and the results of laboratory core studies, a fault model is built based on the interpretation of 2D and 3D seismic data and lineament analysis with determination of the time of fault formation, structural and stratigraphic framework based on interwell correlation and fault models; constructions are adjusted based on the constructed structural and stratigraphic framework using the method of palinspastic reconstructions. They also evaluate the value of the denudation section to determine the maximum immersion depths for each point of the structural and stratigraphic framework and build a paleodepth cube, conduct a lithologic-facies analysis to localize zones of maximum concentration of development of siliceous deposits and determine the facies zones according to which cubes of facies and lithotypes are built, determine the degree of post-sedimentation transformation of siliceous rocks based on plotting the dependence of the predominant form of silica according to the results of laboratory core studies on the depth of maximum immersion of the strata. Next, a petrotype cube is built on the basis of a lithotype cube, taking into account the probable forms of development of silica and a paleodepth cube, basin modeling is carried out taking into account the factors of time, temperature, content of clay and organic components in the siliceous matrix to determine the degree of post-sedimentary transformation of siliceous deposits, the thickness of the phase transition zone is determined and the degree of catagenetic maturity of organic matter determines the zone of predominant forms of silica based on the results of basin modeling. The results of determining the degree of post-sedimentary transformation of siliceous deposits obtained by the basin modeling method and the paleodepth method are compared relative to each other for convergence, the boundary of the beginning of the oil generation zone MK₁ is determined based on the results of basin modeling, promising zones of siliceous fractured reservoirs are determined in the transition zone Opal-KT-α-Quartz, filtered below the boundary of the beginning of the oil generation zone MK₁. The ranks of tectonic disturbances and the directions of local stress states that indicate their formation are determined based on studies of surface exposures of the studied deposits and structural and tectonic analysis. Localization of the zone of development of fracturing and zones of propagation of fractured oil and gas-saturated siliceous reservoirs is carried out.

EFFECT: increasing the accuracy and reliability of the localization of promising zones in oil-source siliceous strata, taking into account the degree of transformation of the oil-source rock, which makes it possible to predict the hydrocarbon content.

1 cl, 9 dwg