GEOLOGICAL SURVEY METHOD Russian patent published in 2012 - IPC G01V1/00 G01V1/28 

FIELD: physics.

SUBSTANCE: natural microseismic background is picked up in the 0.1-20 Hz frequency range. Noise from ground-based manmade sources is filtered. The filtered microseismic background is analysed for presence of hydrocarbon deposits under the microseismic field recording point. Numeric full-wave 2D or 3D simulation of microseism propagation in the geologic environment in the absence of hydrocarbon deposits (H₀ hypothesis) and in the presence of hydrocarbons in one of the possible horizons (H₁ - H_i hypotheses) is also performed. Different geometric dimensions of model hydrocarbon deposits and/or their position in the environment are given. A model microseismic signal is obtained for each investigation point for all investigated hypotheses. A statistically significant number of computational experiments is performed for each hypothesis. As a result, an assembly of realisations of the microseismic process at the investigated territory is obtained for each of the hypotheses put forward. The observed and model signals are compared using statistical methods to determine validity of hypotheses H₀ and H₁ - H_i. The most appropriate hypothesis is determined from the given first and second type error probability levels. If hypothesis H₀ is the most appropriate, there are no hydrocarbon deposits, and if any of the hypotheses H₁ - H_i is the most appropriate, there are hydrocarbon deposits with geometric dimensions and position corresponding to said hypothesis.

EFFECT: high reliability of interpreting microseismic observation data.

11 cl, 9 dwg, 1 tbl