Searching for the "eyes" underground: seismic exploration technology

There is a way to do a "physical examination" of the earth and discover the "internal secrets" of the earth. Do you dare to believe it? Our "eyes" to explore the underground are seismic exploration technology. It is a geophysical exploration method that mainly uses the elasticity and density differences of underground media to observe and analyze the response of the earth to artificially excited seismic waves to infer the properties and morphology of underground rock formations.

Take "3D seismic exploration" as an example, which mainly consists of three steps: field seismic data collection, indoor seismic data processing, and seismic data interpretation. It sounds simple, but it is actually a complex system engineering, and even each step is a system. The three steps are both independent and mutually influential, and each step requires the support of the most advanced computer hardware and software.

The first step is data collection. Since the collection environment can be ocean or land, the geological problems are different, and the construction conditions of each work area are different, the methods of seismic data collection are also different. But in any case, data collection is the most critical step, because if the original data has serious defects, there is no way to repair it, so high-quality field work is the basis for successful seismic exploration.

The second step is data processing. Data processing is to process the original earthquake data obtained from field observations through a large number of calculations and convert the earthquake data into geological language.

The last step is to interpret the seismic data. Geologists analyze and interpret the seismic data to determine the structure of the underground rock formations, find stratigraphic information, and describe and analyze it. In the interpretation process, various maps that reveal underground features are often compiled, and sometimes simulations are used to help understand the changing characteristics of the underground rock formations.

Due to different seismic exploration targets, the applicable scope of seismic exploration equipment is also different. Some are suitable for shallow targets, while others are suitable for deep targets. The equipment used on land and sea is also very different.

On land, large-scale transportation vehicles are usually required, especially for earthquake sources or drilling; on the ocean, the carriers of seismic exploration equipment are mainly ships; in addition, special geographical environments require special transportation vehicles, such as swamps or wetlands, which require the use of amphibious vehicles or hovercraft.

Since the 20th century, seismic exploration has experienced a technological development from two-dimensional to three-dimensional, and then to high-precision three-dimensional. After entering the 21st century, seismic exploration has begun to develop towards four-dimensional, visualization and intelligent.

In addition, with the birth of new computers and the intelligent processing technology, intelligent seismic technology has been rapidly developed and improved, such as borehole monitoring while drilling technology, deep domain seismic information display technology, full vector wave field imaging technology, intelligent oil field development monitoring technology, etc., which have greatly improved the efficiency and accuracy of seismic exploration. In the future, we will continue to expand the limits of underground exploration and make underground geological features more accurately displayed in front of people.