Zenith launches gauge to conquer ground fault challenge
Wednesday, Mar 07, 2012
Downhole monitoring specialist Zenith Oilfield Technology today launched a groundbreaking technology for the oil industry which will ensure operators never miss a beat during artificial lift using electrical submersible pumps (ESP).
Zenith revealed the new ESP gauge Ground Fault Immune at the European Artificial Lift Forum in Aberdeen, where a paper was presented on the results of a demonstration test.
The ESP gauge is immune to ground faults, a persistent problem with this type of artificial lift which affects more than 15% of downhole monitoring systems. Ground Fault Immune spells the end of system failure when a fault occurs on the ESP cable, giving operators the ability to maintain continuous surveillance.
The technology has recently been proven in demonstration tests in the Middle East and the device will be run in trial wells later this year.
Aberdeenshire-based Zenith designs, assembles and supports high-spec technology related to the gathering and analysis of downhole data and the design of completions equipment.
The Ground Fault Immune gauge runs a unique new power and communication system so that insulation break down caused by ground faults will not short the system. Therefore the monitor will continue to run as long as the ESP cable is operational.
In current systems of this nature, when a ground fault occurs with current leakage from the ESP cable, the gauge will lose the signal, cutting off the data transmitted about the operation of the ESP.
Dave Shanks, Development Manager at Zenith, said: “All too often in ESP operations a ground fault will cause downhole monitoring systems to fail and leave operators running blind. While the ESP will still be running, the interference in data transmission means that pressure, fluid levels and temperature readings are unobtainable. Operators are then faced with running motors at lower pumping rates to keep motor temperatures in safe operating areas, and also with a larger head of fluid to make sure the pump does not pump off. This can result in up to 25% reduction in fluid output compared to a pump optimised with a live down hole gauge, resulting in a significant loss of production.
“Ground Fault Immune is considerably more robust than current devices which means that operators are never faced with a gauge failing due to ground faults. Our gauge offers a monitoring solution which cannot be disturbed by these type of faults for the first time.”
The demonstration test verified the performance of the new technology. Fitted to a medium sized ESP, three types of fault were applied to the cable system and demonstrated that the ground fault immune ESP monitoring gauge successfully remained fully operational throughout. The system can operate at 125°C and at pressures of up to 5,000 psi. Logging data at 0.5 seconds per reading, the logger software and diagnostic panel allowed for gauge sensor readings on a real time plot which could be scaled and adjusted by the user.
This technology provides Zenith with a platform for a range of new and exciting products with the ability to provide more electrical power to down hole instrumentation and, with high speed data transmission, gather more accurate and more complex information than has been previously possible.
The new gauge will initially be deployed with the existing Zenith ESP tool, with further applications of this technology to be explored. This development is another in a series of technology breakthroughs by the company.
The successful Z-Sight automated well surveillance system, which has been proven to typically increase oil production by between 6% to 50% from each well, has recently been launched in America and was shortlisted as a finalist in the World Oil Awards’ Best Production Technology category. The company was also awarded the Queen’s Award for Enterprise for the second time in 2011.
With more than 80 staff operating out of 30 countries, the majority of Zenith’s workload comes from oil and gas operators and service companies working and producing in the Middle and Far East.
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