Pressure Balanced Sucker Rod Pump with Engineered Hydrodynamic Valves

A sucker rod pump is an essential component for rod pumping, but it has been limited by use of machined componentry and a ball/seat valve design. Today’s deep, gassy-sluggy, foamy, solids ladened, horizontal wells commonly have high initial liquid rates that are beyond the rate capacity of sucker rod pumping, which can require use of higher operating expense ESP’s or gas lift methods. Improving the rate capacity and reliability of sucker rod pumping in such challenging environments would be highly beneficial for producers.
The sucker rod pump is one component of a complex downhole system of components for sucker rod pumping. Other components of this system include a downhole gas separator, a downhole solids separator, a tubing anchor and sucker rods. To maximize the efficiency and performance of a sucker rod pump, all these components must act together harmoniously to effectively feed the pump on demand with liquid that has been gas and solids depleted – unfortunately, achieving this has been particularly challenging. Consequently, the sucker rod pump still must contend with gas and solids.
Further, with deep high-rate sucker pumping, an acceptable reliability failure frequency has been particularly challenging. Larger and longer stroke length pumping units have improved the rate capacity of sucker rod pumping but have been limited primarily by excessive pressure loss across the pump’s standing/travelling valves, by pump gas interference and by inadequate reliability from damaging solids. Lastly, compressional loading events on the sucker rods at the commencement of each pump downstroke has also reduced system reliability.
An improved sucker rod pump was conceptualized, and design engineered for such challenging environments:
• minimal standing/travelling valve pressure loss at high pump rates and pump plunger velocities,
• solids tolerant at high concentrations of solids (from concentrated solids slugging events),
• can operate efficiently at all inclinations up to 90 degrees, and
• pressure balances the pump’s travelling valve prior to commencement of the pump’s downstroke to avoid compressional loading events and to avoid efficiency losses due to gas interference.
The Vortex Barbell SystemTM pump valves have demonstrated a step change in performance for high inclination pumping conditions. This unique valve design revealed a transformational opportunity to evolve the valve for improving a sucker rod pump at all inclinations. Three-Dimensional (3D) metal printing has gained significant attention in recent years. The ability to now print hard and tough metals has offed an opportunity to engineer and manufacture reliable sucker rod pump valves with very low-pressure losses, minimal flow turbulence and improved solids handling -- we are no longer design limited by the ball and seat design from circa 1938. A new complex shaped hydrodynamically engineered rod pump valve was developed.
A pressure balanced pump, has offered advantages for reducing the negative impacts of pump gas interference and compressional rod loading events. But this pump design can be limited by solids and can require precise pump space-outs. A hypothesis that instead of tapered top barrel section, a rifled channeled top barrel section would solve existing limitations. A rifled channel offered much greater solids tolerance and avoided the need for precise pump space-outs.
Flow loop testing and field trials have indicated promise for improvement. The design process, prototyping and flow loop testing, and well trials/results will be shared.