Abstract
The re-development of a giant offshore field in the United Arab Emirates (UAE) consists predominantly of four artificial islands requiring in most cases extremely long horizontal laterals to reach the reservoir targets. Earlier SPE technical papers (1,2) have introduced the development, testing, qualification, and deployment of the plugged liner technology using the dissolvable plugged nozzles (DPNs). The use of DPN plugged liner technology has resulted in CAPEX savings and enhanced production performance.
The benefits of DPN technology are its simplicity along with its cost effectiveness. However, the dissolvable material has some limitations, such as pressure rating and dissolution time, which are fluid chemistry dependent. To overcome these limits, a new Pressure Actuated Isolation Nozzle Assembly (PAINA) was developed as an alternative to the plugged liner tool for applications where a higher pressure rating is required, as well as on demand opening. Furthermore, the new PAINA also functions as a flow control device during injection and production, enhancing acid jetting effects during bullhead stimulation and reducing brine losses during liner installation.
Liners with PAINAs can be run to TD similar to blank pipe: fluids can be circulated through the inside of the liner without the need for a wash pipe. Once on bottom, non-aqueous drilling fluid is displaced to brine without actuating the isolation mechanism. When the well is ready for production or injection, pressure is applied and the isolation mechanism is activated to establish communication between well and reservoir. These tools were successfully run as flow control devices in water-alternating-gas (WAG) pilot wells. The planning and execution of the initial application will be discussed, along with the tool development, qualification testing, and lessons learned.
The key advantage of this technology is in extending plugged liner applications to cases where other pressure-operated tools are included as part of the liner lower completion. Pressure can be applied to the well multiple times without activating the isolation mechanism as long as the applied pressure is below the actuation pressure.
