Seismic data is one tool used by Weatherby Energy to help in the process of drilling for oil and natural gas. While Weatherby Energy makes use of many scientific principles, understanding seismic data and how it works is one of the most important elements of successful drilling. For investors or those who are interested in learning more about what Weatherby Energy does or how drilling works, learning about seismic data can be a fascinating subject.
What is Seismic Data?
Seismic data are the recordings of seismic waves by a seismograph. The seismograph measures the amplitude of these waves that were produced by some action, like a detonation or earthquake. Because seismic data shows the shape of the waves, it is also referred to as waveform data.
To record these seismic waves, something has to cause vibrations that cause the shock waves to bounce off of formations in the rock. A good example is dropping a rock into a body of water: the seismic waves are the ripples from it. When the ripples hit an object, they are refracted off of it.
When the data is captured, it can be analyzed to form a two dimensional representation of the rock formations under the surface of the land. Since the waves are measured over time, by collecting seismic data, you learn how fast the energy travels through certain substances. This can show viscosity, density, and cracks in the rock formations.
The Process of Collecting Seismic Data
The process of collecting seismic data can vary slightly, but a general overview of the steps can be useful in understanding how seismic data collection works:
First you need to position the geophones, which are the instruments that measure the amount of movement of the ground and the length of time it moves. Early geophones would only show the vertical movement of the land but more modern ones also record horizontal movements in two directions. The up and down or vertical movements made by these shock waves are called pressure waves, or P-waves; side to side movements are shear waves or S-waves.
Next you need something to produce waves and in the beginning of seismic measurement dynamite was used. Now the source of vibrations on land is usually huge vibrator trucks. The truck sits on a pad and moves to produce vibrations. This method is referred to as vibroseis. So the waves are reflected and refracted off of the various types of rock, which goes to the surface and is recorded by the geophones.
The Use of Seismic Data in Oil and Gas Exploration
Collecting seismic data is the most used tool for oil and gas exploration and Weatherby Energy has extensive knowledge of the use of seismic data for this application. One good thing about collecting data in this way is there are no holes to be drilled or pits to be dug to get this information.
Originally seismic data was two dimensional, which showed a slice of the earth. Today it is possible to collect three-dimensional and even four-dimensional data. These require many more seismometers and the data is used to create a 3-D computer model of the volume of earth. Four-dimensional data, also known as time lapse seismic, is simply three-dimensional seismic data taken at different times. This can show changes in the flow of liquids, saturation, pressure, and temperature. This will help determine the rate of depletion of a reservoir and reactions of the reservoir when gas is injected into it or it is flooded with water.
Weatherby Energy keeps abreast of new technology and new developments in the field of seismic data. This allows Weatherby Energy to be at the forefront of new technology and to provide less risk and better value for investors.