By automating the process of data analysis and optimisation, downhole monitoring and completions specialist Zenith Oilfield Technology says its Z-Sight tool facilitates better management of the high volumes of data associated with artificially lifted wells.
According to Zenith's new technology manager Julian Cudmore, Z-Sight takes the hard work out of well surveillance.
'A single well lifted by an electrical submersible pump (ESP) can have 20 or more key data streams associated with its operation,' he explains. 'These include surface data, surface electrical data and downhole gauge data which can be updating more than once per minute resulting in an overload of data. In addition, the operator will need to perform well tests and further calculations by launching the data into well performance software to gain a full understanding of how the well is performing.'
Z-Sight is a dynamic tool, designed to provide real-time recommendations on how best to operate the well to achieve optimum production within the limitations of the lifting equipment.
A comprehensive model of the well and lifting equipment is referenced in real-time against measured data points from surface and downhole pressure and temperature devices. Intelligent algorithms within Z-Sight judge whether the pumping system is running within a desirable operating condition and then perform real time sensitivity studies to assess whether production can be improved. 'Instead of raw data streams the operator is presented with a suggested operating frequency and the potential production gain associated with the new operating point that is within the capability of the well and equipment performance,' notes Cudmore.
All data is displayed on simple dials on a large touch screen showing real time chart and well status report. Well site personnel can quickly see when the pump and well are operating correctly.
Z-Sight, first field trialled on multiple wells in the Middle East, automatically calculates optimum ESP and well protection set points, configured for actual well conditions in real time - ensuring maximum runlife and production integrity. It advises potential production gains with the constraints of both well and pump performance detecting and distinguishing whether either the well or pump is underperforming.
Simple 'well status' operating philosophy filters out unnecessary operator analysis with all processing performed at the well site enabling true real-time analysis.
Key data points that may not be measured in real-time such as water cut, flow rate and bottom hole flowing pressure are all calculated automatically using the comprehensive software model which can be calibrated against any well test data available.
The latest feature to be added to Z-Sight by Zenith, which recently acquired Ziebel UK Monitoring Group (formerly Axon Instruments), is field wide management. Remote access through a secure internet connection facilitates surveillance and control of the lifting equipment from anywhere with a standard web browser. Secure log in presents the operator with a field map of the wells, each with a status flag. The status flag indicates whether a well is not producing, has a pump or well problem that requires attention, has potential for optimisation with a recommendation on potential gains, or is running optimally and requires no further attention.
'The operator can instantly recognise and prioritise wells requiring attention, make informed decisions and action the decisions quickly using the remote control function to start, stop or change operation of the well,' says Cudmore. 'By having remote access and control, operators have complete control of their operations in an instant. They are immediately notified by e-mail or SMS when a well shuts down and production is being lost. The operator then has the ability to resume production immediately through secure remote control of the ESP drive.' OE