Surface Machinery and Methods for Oil-Well Pumping

POWER-TRANSMITTING MACHINERY.

S. C. Sampson, who was in charge of this property for a number of
years, states that the installation and maintenance of this system in
a tropical climate, such as that of India, have been much more ex-
pensive than the installation and operation of a central power or
jack-plant system.
SYSTEMS OF JACK-PLANT OR POWER PUMPING.
The jack-plant or power system of pumping oil wells by groups
was developed about 30 years ago in the oil fields of Pennsylvania
to meet the need for lower operating costs, which the decline in
crude oil prices and production per well necessitated.
There are three types of jack plants or powers: A, Push-and-pull
powers; B, geared powers; and C, band-wheel powers. The first and
last named were originally made chiefly of timber, but in recent years
the tendency has been to make all types of powers of steel, although
some types of band-wheel powers still have the wooden band wheel.
No attempt is made here to discuss the relative merits of these
different types of powers. Both well and poorly designed powers of
each type are on the market and in use. The number and depth of
the wells to be pumped, their relative location, and the operating
conditions to be met must all be considered in deciding the size and
type of power that will give best results.
Poor results from jack plants or powers can be more often
traced to equipment too light for the service required, improper
foundations, or improper alignment of installation than to any de-
fects of the type used. After the type to be used has been chosen
it is well to compare the different designs available and to buy a
make that is well built and has been proved by service.
PUSH-AND-PULL POWERS.
One of the first powers developed in the oil fields was the
push-and-pull type shown in Figure 9. It was made mostly of
timber with wooden pull wheels and 2, by 4 inch main pull lines held
together with bolted steel plates. Many powers of this type were
once used in the oil fields of northern Pennsylvania. The power
proper was serviceable, but the use of wooden pull lines between
the primary and secondary pull wheels was a constant source of
trouble, as the lines often parted at the strapped couplings, especially
during long dry periods in the summer. In addition, there was
considerable lost motion between the pull wheels because of the
difficulty of keeping the wooden pull lines in proper tension. Motion
is also lost because of the working loose of the wooden keys in the
power proper and in the primary and secondary pull wheels. For

67

George, H. C. Surface Machinery and Methods for Oil-Well Pumping. Washington D.C.. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc12407/. Accessed October 21, 2014.