Scientists at Novosibirsk State Technical University (NSTU) are investigating a method for constructing high-precision models of the geological environment for mining and optimizing drilling plans.
According to Evgeny Rabinovich, Professor of the Department of Computer Engineering at NSTU-NETI, Doctor of Technical Sciences, the seismic survey technique is based on studying the travel time of waves from the excitation point to seismic receivers. An acoustic wave behaves differently at the interface of media: it is reflected and refracted. This is due to the fact that the speed of wave propagation depends on the properties of geological media (rock composition, porosity, density, etc.) and changes as it passes through the boundary. The waves propagate from the oscillation source to the seismic receiver, reflecting and refracting at the boundaries of different layers of the medium, and this process repeats itself many times. Graphs of vibrations recorded on the earth's surface by special instruments are grouped into seismograms and analyzed to determine the properties of rocks and the structure of the subsurface. The basis for determining the types of waves and the depth of geological structures is a hodograph, a graph of the dependence of the time of arrival of a seismic wave on the distance between the excitation source and the receiver.
Seismic location technology uses an approach that makes it possible to build high-quality models of the geological environment without using a solution to the inverse kinematic problem of seismic exploration, which is incorrect. These tasks may have several different solutions with the same source data, and their solutions may be unstable to small errors in the data. This leads to significant errors in calculating the model parameters.
"Seismic location technology replaces the incorrect solution of the inverse problem with a set of correct sequential solutions to direct kinematic seismic exploration problems. The direct task is to find the arrival time of seismic waves on the seismic receivers at the specified parameters.: the speed of wave propagation, the geometry of the interface, the distance from the source to the receiver, the type of wave and the physical properties of the medium," explains Evgeny Rabinovich.
The seismic location technology uses algorithms based on the idea of radar methods, the scientist notes. This is a quadrature correlation that ensures optimal reception and detection of reflected seismic pulses in conditions of noise and interference. This algorithm also filters the data according to the shape of the model seismic pulse. A significant advantage of such filtering is that it does not distort the frequency components of the seismic signal. This is an algorithm for super-resolution of reflected seismic pulses based on a seismic digital antenna array, which is designed to improve the accuracy of calculating the geometric parameters of reflecting boundaries. Even a minor error in determining the configuration of these reservoir boundaries can lead to the risk of very expensive drilling of empty wells.
"If we don't know exactly the path that the seismic wave traveled, we won't get a real configuration of the location of objects underground. It is necessary to ensure high accuracy in constructing a model of the deep boundaries of the medium strata. This can be achieved through a highly accurate assessment of the trajectory of wave propagation through all layers of the medium, which makes it possible to identify the real geometric parameters of the boundaries and the depth-velocity characteristics of geological strata," said Evgeny Rabinovich.
The theoretical basis of the research conducted at NSTU-NETI is represented by algorithms for detecting seismic reflection pulses and localizing their sources, as well as a high-resolution algorithm for calculating geometric parameters of boundaries. As part of the study, a computer simulation of the passage of a seismic wave from an oscillation source to a seismic observation system was performed, which makes it possible to determine the structure of the earth's interior with high accuracy.
The university's scientists have developed software for automatic detection of reflected seismic waves and accurate determination of the spatial position of their sources (hypocenters) based on seismic observations. In 2025, a certificate of state registration of a computer program was received.
The main advantages of seismic location technology are high accuracy in determining the configuration of reservoir boundaries, reducing the risks of inefficient drilling, and reducing the cost of exploration. The field of application is the search for oil deposits in areas with complex geological structures, exploration of unexplored areas to identify potential oil and gas structures, as well as obtaining information about productive formations already in operation or subjected to hydraulic fracturing.