Pumpjack

Deep pumps are used as conveyor means for the recovery of subterranean fluids stored when the reservoir pressure is not sufficient to move independently and in a sufficient amount to the surface. Usually promoted oil with them. Other applications include the promotion of brine and spa waters.

Types

We distinguish several types of deep well pump:

The image of most oil fields of drill deep well pump - named because of their appearance and motion also horsehead pumps or Nick donkey - coined. Here is the actual pump mechanism - a piston with check valves - in a separate pipe string in the well near the oil-bearing stratum. The piston is displaced by means of a rod screwed by a pump block located at the earth's surface in a continuous up and down movement. The horse's head consists of a circular arc segment to which a steel cable (pair) is clamped above, which exerts always train and never pressure on the rod.

The drive is mostly electric. In the presence of sufficient energy in the oil dissolved gases containing, however, a portion of this gas on the spot by means of a degasser can be separated from the material to be conveyed and a gas engine for driving the pump is supplied.

In the early days of oil production Central drives were common. The type most commonly used, an internal combustion engine operating at a horizontal mechanism eccentric disks were suspended from the boom. The linkage was thus set into a back and forth motion, often transferred over several hundreds of meters to the pump drives and were converted there into an up and down motion. With an engine more than ten deep pumps were often driven. In some oil fields in the U.S. such central drives are used to today.

Depending on the pump type and size of the working stroke is 1 to 5 m. Two and a half to twelve strokes per minute usual. The linkage submersible pump can be used to conveyor depths of about 2500 m economically. For larger depths other pump systems are better suited due to the large weight of the liquid column to be lifted.

Especially for holes with a deflected course in which a steadily moving rod would wear out quickly, a hydraulic drive offers. The actual pump mechanism - as in the low- pump, a piston rod with a non-return valve - is actuated by means of a fitting directly to the hydraulic cylinder piston, is connected via a separate pipe to a hydraulic pump located at the surface. The oil obtained is used as a resource of the entire pumping system.

Alternatives

Instead of a piston pump, a progressive cavity pump ( PCP technical term - English progressive cavity pump) be installed in the borehole, which is put on a screw rod with a power head at the surface in rotation. For deep holes or distracted during a mounted directly to the eccentric screw pump electric motor is common. Power is supplied by an objective in downhole cable. The more commonly used in the petroleum industry term for electrically operated submersible pumps is ESP (English electrical submersible pump).

Small rod deep pump with which to Bad Hall medicinal water is obtained.

Power head for a mounted downhole progressive cavity pump.