Applications

Early versions of progressing cavity pumping systems were used in Canadian heavy oil and bitumen applications in the early 1980's. By 1986, PC pumps had made their way into coalbed methane applications in the United States. Further improvements in the technology and manufacturing techniques allowed for expanded use in higher rate medium crude oil applications. In recent years, improvements in elastomers have allowed the use of PC pumps in light oil and elevated temperature applications.

Heavy oil and bitumen applications are commonly defined in the industry as those producing oil with an API gravity less than 20°. These conditions are common in Canada, Russia, Venezuela and China. Problems associated with heavy oil and bitumen are high viscosity, high flow losses, low to moderate flow rates, high sand cuts and rod string/tubing wear. Directional and horizontal wells are often used to ensure viable development of the reservoir. PC pumps are attractive in these conditions due to their ability to handle viscous, abrasive, multiphase fluids.

Most coalbeds are highly saturated with water that must be removed to lower formation pressure and initiate gas movement. Often the water contains a high concentration of coal particles and dissolved solids. Traditional methods of dewatering such as beam and electrical submersible systems had difficulty handling the produced solids. The ability of PC pumps to handle coal fines, sand particles and gaseous fluids, combined with lower capital and operating costs make them a good candidate for coalbed dewatering.

Medium crude oil applications are generally considered those that produce oil with an API between 18° and 30°. Medium crude oil has lower viscosity and tends to have higher gas to oil ratios when compared to heavy oil operations. Many operations produce a large amount of water (sometimes exceeding 95%) along with sand, C02 and H2S. In medium crude applications, lower capital and operating costs are the primary advantages that PC pumping systems have over other artificial lift methods.

Light oil applications are generally considered those that produce oil with an API greater than 30°. Light oil has a lower viscosity and contains higher levels of aromatics and gas. A large proportion of the production is water with minimal sand production. Sweet (CO2) and sour (H2S) gases as well as paraffin may also be present in significant quantities. In light oil applications, higher overall efficiency of PC pumping systems makes them an attractive alternative to beam pumps, electric submersible pumps and gas lift systems that have traditionally been used.

Elevated temperature applications are considered those in which the fluid level is greater than 50°C. This also includes hot fluid injection, mature steamfloods and cyclic steam operations. For low temperature applications (<50°C), thermal expansion necessitates special equipment and pump sizing practices. For high temperature applications (>50°C), attention must be paid to the effect of temperature on the pump elastomer. Although the use of PC pumping systems in high temperatures is still limited, both manufacturers and operators continue to actively pursue developments to increase the temperature range of PC pumps.