This report investigates the use of Progressive Cavity Pumps (PCP) within Queensland Coal Seam Gas (CSG) applications. Four major project sections were identified from the start and all completed as planned.
Section 1, prior art and research, was a success and provides a good learning platform about basic CSG drilling methods and PCP operation and production applications. Section 3, ‘off the shelf’ optimisation, was the most successful project section. As per critical analysis of the prior art, Section 3 investigated the elastomer technology used in the pumps and the pump’s geometric design. The research concluded that multiphase flow and production of solids within the pumped fluids were the most critical causes of pump wear and failures. Therefore these two topics were investigated as aspects of pump design that most affect the ability of the pump to produce solids. The study of elastomers ran as expected and demonstrated that pumps being deployed in Queensland were in fact using the most functional rubber. The geometric study was split in two parts, investigating the effect of the swept angle of the rotor and the effect of volumetric efficiency brought about by specific internal size ratios. The swept angle study drew few conclusions and failed to prove theoretical expectations. The volumetric study clearly demonstrated that improved volumetric efficiency brought about by specific internal ratios does improve the pump’s resistance to wear. Section 4 was aimed at possible future developments of PCP technology. This was less successful. Most development of PCP technology surrounds other pieces of the well completion, preventing solids from ever entering the pump and improving the quality of well structure itself; all preventative measures, rather than developing the pump itself for more effective use.
The overall conclusions are mostly as expected. PCP technology is almost perfectly optimised for CSG use, as would be expected from such a large and vital industry. Some of the theories behind pump optimisation from literature were proven; however it was shown and concluded that other forms of optimisation would be more effective for the same effort and energy invested. This again was demonstrated by the future development section highlighting most future developments moving towards external technology aimed at preventative measures of pump optimisation.