IDENTIFYING ZONES FOR REFRAC USING A NEW DOWNHOLE TESTING TOOL
- 1. Downhole Testing for Refrac A new downhole tool for testing individual zones in multi-stage wells
- 2. Features Straddle packer with downhole pump Multiple tests with one run Drawdown and buildup tests Fluid identification Pump Bypass for flowing wells E-coil conveyed – mono-conductor cable Small O.D. for 4-½" casing Flow past the tool for cleaning debris, etc Emergency planning
- 3. Bypass Valve Sensors Check Valve Coil Tubing Shift Down Unloader Upper Packer Flow Rate Valve Burst Disk Anchor Lower Packer Intake Piston Pump
- 4. Specifications Tool O.D. 3.6" Min hole size 4.0" Max hole size 7-¼" Tool length 15.8 m ( 52 ft) Max pressure 10,000 psi Max temp 350 degF
- 5. Downhole pump Reciprocating piston pump Pump Rate 0.1 - 2.0 ltr/min 0.9 - 18 bpd Precision stroke 0.5 - 332 cc Pump from between packers to coil/casing annulus Custom check valves for dirty fluids Bypass valve for flowing gas or oil wells
- 6. Packers set and released by coiled tubing flow and movement Packer Assembly & Intake Sub Lower Packer Upper Packer Unloader
- 7. Important factors with transient testing Permeability Fluid type Volume of drawdown Minimize storage effect Pressure sensor Resolution Reaction time Stability
- 8. ✓Fast acting MEMS sensor ✓Resolution is 0.00005% of FS ✓Accuracy 0.01% FS ✓10,000 psi FS Pressures Measured Flowline Coiled tubing Annulus Pistonchamber(Optional)
- 9. Fluid identification sensors Conductivity Optical Bubble counting can show continuous phase
- 10. NMR sensor • 14 isotopes monitored simultaneously • Programmable for other isotopes • Multi-phase flowrate • Real time AI analysis • Density, viscosity, temperature and pH • Gas composition
- 11. Applications Fracturing information Zones producing excessive water or gas Water flood monitoring Reservoir knowledge Identify communication between zones or wells Reason for poor production
- 12. Fracturing information • Zones fracture effectiveness • Depleted zones • Fracture effectiveness • Fracture geometry • Communication with other zones or wells • Before and after frac comparison
- 13. Pressure transient analysis See fracture properties by slope change Permeability, reservoir pressure and production by stage Minimized wellbore storage Validate reservoir models
- 14. Job procedure 1 Pull tubing and pump from the well. Wait for stable fluid level. 2 Monitor data while running in well on e- coil 3 Correlate depth with real time CCL 4 Position and set packers by pumping down coil faster than threshold vel ocity 5 After straddle packers set maintain coil pressure 6 Use downhol e pump to drawdown pretest volume for buildup test 7 Pump from reservoir into annulus until fluid type mixture is constant. 8 Shift coil to unload coil pressure and de- energize pac kers 9 Move to the next stage
- 15. Real Time Software Control ❑High speed telemetry – up to 350 kbps ❑Real Time Pump Control and Sensor Monitoring ❑Normal sampling rate of 10 points per second per sensor
- 16. Pumping at different rates
- 17. Full test at 200 m
- 18. Fluid ID transition during test
- 19. Logging out