Based in Addison, Texas, Sentry Energy specializes in extracting oil from wells previously thought to be dry through a combination of cutting-edge extraction techniques and prudent exploration choices. Geologists generally locate oil and natural gas while working for oil companies or exploration firms.
When looking for a likely reservoir, geologists take into account the necessary elements for oil or gas to form and accumulate. A viable deposit must have source rock from which the oil is produced, porous reservoir rock to hold the oil, and trap rock to prevent the oil from escaping and to collect it in an accessible deposit. Early oil prospectors looked for oil and gas using clues on the surface, including features of the land, the kind of rock and soil found on the surface, and core samples obtained through shallow drilling. With these pieces of information, they then worked to make an educated guess about where oil might be.
Today, scientists utilize a number of high tech tools to improve their accuracy, including satellite imagery to examine the terrain, gravity meters to measure changes in the Earth’s gravitational pull due to oil, and magnetometers to examine the Earth’s magnetic field. Geologists also employ very sensitive detectors called sniffers to find hydrocarbons that suggest the presence of oil.
Finally, they use the science of seismology, in which they produce shock waves or vibrations that pass through the layers of the earth and reflect back, revealing the composition of the Earth’s crust much as a bat’s sonar reveals the objects ahead. Seismic surveys use a number of sources of vibration, including compressed air guns, thumper trucks, and explosives. The rate at which the vibrations travel through the ground varies depending on the density of the layers of rock. With sensitive microphones, geologists pick up the reflections of these shock waves and through interpretations they discover trapped oil or gas.