Meanwhile, in France, Conrad Schlumberger had been experimenting with measuring the electrical resistivity of the earth since 1912, proving that electrical soundings could be used to build up a picture of the layering of strata within the earth. Clarence Karcher was working on a seismograph which could record surface-generated sound waves reflected from horizons deep within the earth, resulting in 1928 in the first oil discovery by seismic reflection. But by 1924 his method of estimating the depth to geological formations by setting off an explosion and measuring the time taken for refracted sound waves to travel through rocks had already been used to discover an oilfield in Texas. So when German engineer Ludger Mintrop began experimenting with using the way sound travels through the earth to locate the position of heavy artillery pieces during World War I, he had little idea that his work would have important and more peaceable applications. Having obtained an overview, he can correctly extrapolate local observations made on outcrops…”Īlthough humans have been using hydrocarbons as an energy source for centuries, the discovery of the majority of oil accumulations before the 20th century had been the result of digging or drilling near known oil and gas seeps. “…the practical ability to conduct measurements covering vast expanses of terrain at a reasonable cost and to carry out uninterrupted exploration renders the geologist’s conclusions much more reliable. Source: CGGVeritas Early geophysical surveying in Tunisia in 1957.
During the 1930s, 40s and 50s CGG had expanded to have survey teams in many countries, including Gabon, India, Algeria, Morocco and Canada.