Steve Klein, BMW Pump Inc.
The Progressive Cavity Pump (PCP) has been used in down-hole applications for over fifteen (15) years and has progressed from only one model and one elastomer to over twenty models and several different elastomers. The depth range for the rod driven pump system has increased from 1000" to 6000" and even a few 8000" applications. These applications call for special elastomers and considerations as to the fit and/or design of the pump and the system. Down-hole pump displacements have increased from 5 to over 1000 bpd/l00 t-pm. The resultant torsional requirements for the large pump designs have reached the limits of conventional sucker rods, therefore, new methods for rotating and transmitting torque to the pump are being conceptualized, designed and tested. New developments, in the past two to three years, that will be covered in the following text consist of elastomers; rotor coatings; drive systems; rod centralizers; and rod-less systems as well as new applications where PCP's are being utilized, i.e. high temperature, CO2 and H2S.