Page 167 - Petroleum Production Engineering, A Computer-Assisted Approach

Guo, Boyun / Computer Assited Petroleum Production Engg 0750682701_chap12 Final Proof page 163 4.1.2007 2:43pm Compositor Name: SJoearun

SUCKER ROD PUMPING 12/163
The American Petroleum Institute (API) has established beam counterbalance units, and M is for Mark II units.
designations for sucker rod pumping units using a string of The second field is the code for peak torque rating in
characters containing four fields. For example, thousands of inch-pounds and gear reducer. D stands for
double-reduction gear reducer. The third field is the code
C---228D---200---74:
for PRL rating in hundreds of pounds. The last field is the
The first field is the code for type of pumping unit. C is for code for stroke length in inches.
conventional units, A is for air-balanced units, B is for

Walking beam

Fulcrum
Pitman Force

Well
load

Counter
balance

(a)

Walking beam

Fulcrum
Pitman Force

Well
load

Counter
balance

(b)

Walking beam

Fulcrum Force
Pitman Counter balance Well
load

(c)
Figure 12.2 Sketch of three types of pumping units: (a) conventional unit; (b) Lufkin Mark II Unit; (c) air-balanced unit.