1. Mike Webster Intelligent Wells Project UTG Aberdeen
FORCE Seminar Stavanger Norway 28th-29th March, 2001

2. Fiber Optic Sensors Development and Challenges
Mike Webster Intelligent Wells Project UTG Aberdeen
FORCE Seminar Stavanger Norway 28th-29th March, 2001

3. Why should we be interested in optical sensors ?
Intelligent Wells Project mission: Develop technologies for deepwater developments that provide reliable reservoir surveillance information and allow control of zonal contribution without intervening into the wells.
Goal: Achieve a 90% system survivability over 5 years.
Current electrical system performance falls short of assets goals.
Current Electronic Flowmeter and Gauge Track Record

4. Drivers for Fiber Optic systems
Potential for Increased reliability of the downhole sensors
Subsurface is passive
Surface optoelectronics can be maintained and upgraded
Ability to install a large number of varied sensor types
Ability to survive in harsh environments (particularly temperature)
Distributed sensing removes the need to select point of measurement
Choice of fixed installation or renewable hydraulic deployments
Leverage off large telecoms R&D spend

5. Fiber Optic Sensing Implementations
Point Sensor
Single Sensor
location
Quasi-Distributed Sensor
Multiple Sensor
locations
Distributed Sensor
Continuous Sensor

6. Point Sensor Fiber Optic Monitoring Systems
Flow/Phase Fraction
Pressure/Temperature
Seismic

7. Optical Pressure Gauge Gaps and Trials
Technology Development and Field Trials
Optoplan gauges deployed in Gyda (Aug 94)
First Cidra Bragg grating installed in Pompano April 2000
Large number of installations planned in 2001 including Valhall
Technology Gaps
Optical wet connector enhancements
Subsea integration and deployment of optical systems

8. Distributed Temperature Current Claims
Turnaround sub
Double ended
Tubing
Control line
& fibre
Check valve
Perforations
Single ended
+/-0.5 deg C resolution at 2m up to 30 km
+/-0.1 deg C resolution at 1m up to 12 km

9. Current/Future DTS Installations
Current DTS Installations
Wytch Farm K-07 April 97 ESP Pump monitoring
Wytch Farm M-12 May 98 Commingled Producer/Injector
Wytch Farm M-17 Sept 99 Producer
Marlin A-06 Dec 00 VIT surveillance
Marlin A-04 Feb 01 VIT surveillance
Future Installations
Trinidad Mahogany May wells gas inflow monitroring
Chirag Sept 01 Sand face monitoring
Wytch Farm Aug 01 ESP Producers
supported by an injector
The temperature below 4240m from January to March have stablised, whilst above this depth shows an increase during the period that water cut increases from 25% - 35%
water salinity increased with watercut indicating formation water along with injection water
note the correlation between the cold water entry points and the porosity curve

10. How can we validate DTS data ?
DTS Thermal Profile
PLT Thermal Profile
Numerical Model

11. Thermal Modelling of PLT Data

12. Field example: Wytch Farm M-17 watercut increase
supported by an injector
The temperature below 4240m from January to March have stablised, whilst above this depth shows an increase during the period that water cut increases from 25% - 35%
water salinity increased with watercut indicating formation water along with injection water
note the correlation between the cold water entry points and the porosity curve

13. Field example: Wytch Farm M-17 thermal profile
supported by an injector
The temperature below 4240m from January to March have stablised, whilst above this depth shows an increase during the period that water cut increases from 25% - 35%
water salinity increased with watercut indicating formation water along with injection water
note the correlation between the cold water entry points and the porosity curve

14. Where do we want to go with DTS ?
Increased deployment of DTS in a variety of environments
Single ended vs Double
Pump down vs hard wire
Bench test all current DTS optoelectronics systems
Deploy DTS fiber with optical point measurement devices
Encourage the inclusion of DTS fiber in downhole electrical cable
Enhance current DTS performance to achieve the following spec
Thermal Resolution <0.1 deg C
Spatial resolution <3m
Distance from light source 20km
Sample time <24hrs
supported by an injector
The temperature below 4240m from January to March have stablised, whilst above this depth shows an increase during the period that water cut increases from 25% - 35%
water salinity increased with watercut indicating formation water along with injection water
note the correlation between the cold water entry points and the porosity curve

15. BP Intelligent Wells Optical Objectives 2001
Comprehensive Reliability assessment of fiber optic systems
Increased utilization of optical pressure gauges company wide
Development of downhole and tubing hanger optical wet connects
Extended range DTS system
Seabed optical architecture and integration
Integration of fiber into well components associated with deep water completions
Integration of fiber onto sand screens / expandable screens
supported by an injector
The temperature below 4240m from January to March have stablised, whilst above this depth shows an increase during the period that water cut increases from 25% - 35%
water salinity increased with watercut indicating formation water along with injection water
note the correlation between the cold water entry points and the porosity curve

16. The Vision

17. continuous pressure and saturation monitoring
Continuous Surveillance =
continuous pressure and saturation monitoring +
Intelligent Wells

18. Mike Webster Intelligent Wells Project UTG Aberdeen
FORCE Seminar Stavanger Norway 28th-29th March, 2001