Oil pump or 'nodding donkey' being used to draw oil out of the ground. It does this using a series of non- return valves (not seen). When an oil well is newly drilled,the oil is usually at a high enough pressure to force the fluid out without pumping. Over time this pressure falls,and eventually an oil pump is required to draw the oil out at an economic rate. Even with the use of oil pumps,only 30-50% of oil can be extracted. Photographed in Trinidad | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Nunuk, David |
Bildgröße: | 5159 px × 3481 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |