Title : Design and construction of a spool deployed fiber optic gauge array for sand- Face monitoring
Abstract:
A critical element of Smartwells is permanent downhole monitoring system. Currently Inflow Control Devices (ICDs) do not have any real-time monitoring of the annulus and tubing pressures. Production Logging Tool (PLT) or Formation Scanner Imager (FSI) only allows monitoring inside the tubing but are very expensive to run and provide onetime data. Real-time pressure and temperature data could potentially identify flowing zones, detect crossflow, identify communication between compartments, detect plugged ICDs or leaks through closed sleeve, and even allow for flow rate estimation from each compartment using flow equations. This paper discusses the design and construction of a spoolable fiber optic gauge system that addresses the need for a cost-effective solution to continuous multipoint sand face production monitoring. A fiber optic gauge array system designed for monitoring ICDs has been developed. The system features: a spooled deployment system to reduce rig time, a low-cost annulus/tubing pressure access technique, a technique for ensuring tubing string alignment, a redundant architecture that facilitates fault tolerant operation and support for Distributed Acoustic Sensing (DAS), Distributed Temperature Sensing (DTS), and Vertical Seismic Profiling (VSP) systems within the architecture. This system uses NACE qualified materials in its construction and exploits the unique multiplexing capability of Fiber Bragg Grating optical sensing technology to provide permanent downhole distributed pressure and temperature sensing (DPTS) using sensor array. A key early application of the system is to permanently monitor downhole ICDs and differential pressure against ICDs. The system comprises an array of optical Pressure/Temperature gauges connected by a fiber optic cable to surface instrumentation. This spoolable solution can measure both tubing and annulus pressure and also incorporates a fully redundant system. The fiber system is divided into a primary connection and a redundancy connection. The primary fiber will be permanently connected to the surface instrument. The redundancy fiber will be connected to a surface instrument in the event of damage to the primary fiber connections. An additional line of reliability is provided through its redundant architecture, ensuring continuous data acquisition. The design elements, components of the system and system architecture are described. Engineering design has been based on running the spoolable ICD Monitoring System in the annular space between a 4 ½” completion tubing inside a 6 1/8” open hole. The array includes Fiber Optic gauges, Splice Boxes, Connection Block, Jumper Tube and Ported Coupling, all assembled and placed under a special protective clamp that has been designed to achieve a running diameter of 5 ¾” achieving the recommended 3/8” clearance. All connections to the downhole cable will be made with pressure-testable metal-to-metal compression fittings. Rigorous qualification to benchmark industry standards was conducted to provide design assurance and quality requirements for new technology designs through standardized verification and validation criteria. This technology allows real-time pressure/temperature measurement across all ICD compartments with minimal investment cost. If successful, this will eliminate the need for frequent PLTs in ICD wells as the differential pressure measurement can be converted to flow rate estimation, resulting in significant cost saving and well intervention reduction for operators.
Audience Take Away:
- Business and Technology drivers for development of this spoolable fiber optic technology
- Overview of the system architecture, design elements, operating principles
- Various applications for this novel low-cost permanent monitoring solution
