As the need to maximise returns from reservoirs increases and more focus is put on innovation and technology, companies such as Tendeka have developed solutions aimed at adding value, reducing uncertainty and maximising recovery from their client’s wells. Included in this is their innovative portfolio of wireless intelligent completion products for brown and greenfield applications.
To date wireless technology has relied on a string of batteries to supply the power; however these can be limited by short life spans downhole. Tendeka contacted Petrex to assist in the design of an alternative power source based on the premise that energy could be extracted from the well flow and converted to electricity using a permanent magnet generator.
Petrex commenced the project in August 2012 and began an in depth concept development phase. Petrex undertook a detailed technology review of existing flow based energy generators and developed concepts using the best ideas. Petrex employed CFD analysis to determine the design of the Impellor, as was suspected; the energy available from the flow was significant.
The resultant impeller was designed to harness the flow and capture only the small percentage of power available. An initial concern was how to seal against a rotating shaft that will generate speeds between 300-2000rpm over a five year period downhole. Such was the challenge, Petrex took the innovative approach to negate the need for hard fastening seals and instead allow well fluids to enter the internal body of the generator.
Working alongside the client and a specialist in electromagnetics this was accomplished by taking a fresh approach to the internal design and build of the tool while also understanding the effect of erosion and corrosion. The result is a downhole tool that has the potential to operate well beyond its required operational life purely by removing the obstacles that would have caused its premature failure.
Following a detailed concept review and FMEA, Petrex commenced the detailed design and build of the prototype. To enable a quick turnaround on manufactured parts Petrex employed Additive Layer Manufacturing (ALM) to produce the Impellor in Titanium. This is believed to be the first application of ALM within the Oil and Gas industry. Following this build phase, the energy generator was tested in Tendeka’s flow loop mid-December. This test provided excellent results in line with expectations.
Further testing has benchmarked the energy production at a wide range of well conditions. Further work is on-going to develop the prototype further to suit a wide range of well conditions and installations. Petrex achieved this rapid project schedule (17 weeks) due to the use of our own internal design and innovation procedure. This ensures that significant time is spent understand the challenge and generating ideas.
This in turn leads to an optimised and efficient detail and build phase. Tendeka expect to deploy the prototype within a client well mid-2013. The production version of the energy generator will operate in 10000psi, 135°C and last for over 5 years without intervention.