Going deep under water oil drilling - the basics Source : Expro
It ’ s over six months now since the first oil was pumped from the Western Region ’ s Jubilee Field and oil is constantly in the news . Oilcity magazine takes a closer look at this important resource .
Way back in 1859 Edwin Drake built the first oil rig in Pennsylvania , USA . By today ’ s standards it was very shallow - a mere 21 metres ( 69.5 feet ) - and produced between eight and 10 barrels of crude oil per day .| Fig . 7 | Within a few short months oil fields were springing up across the northwestern Pennsylvania | Fig . 8 | countryside and the petroleum industry was born .
Going deep under water oil drilling - the basics Source : Expro
How Odoes petroleum form ? ver millennia , as plants and animals die , they fall to the bottom of the sea or are washed by rivers , floods and run-off from the land into basins . Here they are covered in layers of sand and silt and , over a long period of time , these layers built up to thousands of metres , causing huge pressure and temperature . The residue left from the tiny plants and animals is subjected to a chemical reaction breaking them down into compounds made of hydrogen and carbon atoms commonly known as hydrocarbons which saturate the large areas of rock underneath . | Fig . 3 |
How Wdo we find oil ? hile some oil is relatively easily accessible either on land or in shallow water other deposits lie deep under the ocean floor , as is the case in the Jubilee Field . Modern oil geologists employ a variety of methods to find oil . They examine surface rocks and terrain , with the additional help of satellite images . They can use sensitive gravity meters to measure tiny changes in the earth ’ s gravitational field that could indicate flowing oil , as well as sensitive magnetometers to measure tiny changes in the earth ’ s magnetic field caused by flowing oil . They can detect hydrocarbons using sensitive electronic noses called sniffers . Finally , and most commonly , they use seismology , creating shock waves that pass through hidden rock layers and interpreting the waves that are reflected back to the surface . The shock waves travel beneath the surface of the Earth and are reflected back by the various rock layers . The reflections travel at different speeds depending upon the type or density of rock layers through which they must pass . Sensitive microphones or vibration detectors detect the reflections of the shock waves - hydrophones over water , seismometers over land . Seismologists interpret the readings for signs of oil and gas traps . Once geologists find a prospective oil strike , they mark the location using GPS coordinates on land or by marker buoys on water . | Fig . 6 |
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