To improve and control flow in water injection wells, Tendeka has completed a field trial with a major operator for its sand control technology, Cascade³. The well screen and flow control completion system uses intrinsic check-valves built into the lower completion to prevent sand production caused by adverse flow conditions, such as back-flow, cross-flow and water-hammer, during shut-ins. The tool features a high-density array of non-return valves to allow for high injection rates with low back pressure.
The project was initiated in 2014 by the operator in partnership with Tendeka to develop a cost-effective solution to increase the life expectancy of water injection wells and improve oil production and recovery.
“The overall objective of Cascade³ is to prevent the production of sand into the wellbore in water injection wells. Conventional sand control techniques are often not effective in the transient conditions that exist when injection pumps are shut down, and many injector wells can suffer a loss of injectivity due to sand fill. Deploying Cascade3 not only eliminates this failure mode, but it also means that more expensive gravel-packing solutions are not required,” Annabel Green, Tendeka’s Chief Technology Officer, said
The three-year R&D project culminated with a field trial in a salt water disposal well in the Permian Basin in March 2018. This comprised of unfiltered and untreated produced water and provided a suitable test lab to study valve performance. The capabilities of the technology were evaluated by simulating the effects of water-hammer and cross-flow and exposing the equipment to long-term injection in a harsh downhole environment.
To observe and test the valves, the completion was configured with tubing and annulus memory gauges and a sliding sleeve to enable the assembly to be bypassed to provide a baseline performance.
During the field trial, the checking functionality of the non-return valves was demonstrated, and multiple rapid shut-in events were carried out. Data collected during the trial confirmed the correct operation of the system and that the non-return valves had no detrimental effect on injection performance.
The well has now been put on full-time water disposal duty to observe the long-term effects of injection on the valves.
“Without sustained water injection, several offshore Gulf of Mexico fields are at risk of losing production as reservoir pressure falls below the bubble point. The field trial has shown that this technology can safeguard injection rates over a longer period of time,” added Ms Green.
“The potential CAPEX savings related to fewer injection wells drilled or re-drilled over the life of these offshore oil and gas assets is considerable. This relatively simple and easily installed technology will provide operators with improved pressure support and sweep, ultimately increasing oil recovery. Although developed for the extreme environments in the Gulf of Mexico the same issues are encountered in many oil producing basins and the technology can be broadly applied.”
Cascade3 is currently scheduled for installation in three wells in Africa, and plans are in progress for its implementation for a deepwater asset in the Gulf of Mexico.