Finding a reliable artificial lift pumping system for heavy oil thermal recovery has been a challenge mainly due to the high operating temperatures (>150°C). Available options such as Rod Pumps and Electrical Submersible Pumps (ESP), which are well proven in the industry, are not particularly well suited to thermal production. While Rod Pumps offer high temperature service, they are limited in the flowrate they can deliver. ESPs on the other hand, can handle high volumes of low viscosity fluids, but are still limited in terms of maximum operating temperature.
Progressing Cavity Pumps (PCP), with elastomeric stator, is economic to run and have done well in heavy oil cold production. These elastomers are however limited in temperature (<150°C). Through research work conducted by PCM and TOTAL, Metal PCP technology has been developed to meet the high temperature requirement of SAGD and other thermal recovery processes. Three models of the Metal PCP are now available to cover a wide range of flow rates for heavy oil production.
This paper presents an update on the Metal PCP development and the results of the world's first SAGD field trial of this type of pump currently on-going in Canada in the Joslyn field. Field performance data are discussed comparing high temperature ESP and metal PCP in actual LP-SAGD conditions.
Four SAGD well pairs were initially equipped with high temperature ESP. Another well pair was equipped with metal PCP. This well has been running since mid October 2006 without problems, in spite of low pressure at pump intake, close to steam flashing conditions. Production rate reached 200m3/d of liquid at 340rpm, giving a volumetric efficiency of 53%. Intake temperature is 160°C due to the LP-SAGD condition of the field. However, this pump is rated up to 350°C.
This first field trial shows the metal PCP as a promising artificial lift technology for hot production. Following this encouraging trial, a second metal PCP has been installed with success in the same field and more installations were decided eventually. Thus, all ESP initially installed were replaced by PCP and nine wells are producing with Metal PCPs currently.