Resistivity MWD

Phoenix Technology Services’ WPR sub is a spatially compensated, dual frequency (400 kHz & 2 MHz), dual spacing device designed for wireline-equivalent Logging- While-Drilling (LWD) and Measurements-After-Drilling (MAD) services in all well types. Applications include geosteering, correlation, pore pressure trend analysis, casing point selection, wireline replacement, logging while tripping and logging with and without the flow switch enabled (for air- and foam-drilled wells).

WPR’s symmetrical design, with centrally located receive antennas, provides realtime compensation, eliminates invasion effects due to measurement delays, and improves accuracy by canceling variations in receiver channels.

WPR operates in all mud types including oil-based and salt-saturated and provides real-time resistivity with flexible transmission formats.

High-resolution data is stored in downhole memory which can be retrieved and processed during trips.

Phoenix provides a complete set of software-enabled borehole corrections and applications with WPR, including a dipping bed model for geosteering.

Phoenix offers a Pressure-While-Drilling (PWD) option for 4.75 in., 6.75 in. and 8.0 in.

WPR General Specifications

Tool Sizes & Maximum Dogleg Severity

 Maximum Dogleg Severity 
“Tool Size”Borehole SizeSlidingRotatingConnection
3.5 in.
(89 mm)		 4.625 - 4.75 in.
(117 - 121 mm)		 40°/100 ft.
(70°/100 ft. with flex-joints for short radius wells)		 16°/100 ft.
(25°/100 ft. with flex-joints for short radius wells)		 2 7/8 AOH
4.75 in.
(121 mm)		 5.625 - 6.125 in.
(142 - 165 mm)		 25°/100 ft. 13°/100 ft. NC38
6.75 in.
(172 mm)		 8.375 - 9.875 in.
(213 - 251 mm)		 24°/100 ft. 10°/100 ft. NC50
8.0 in.
(204 mm)		 12.125 - 14.75 in.
(308 - 375 mm)		 15°/100 ft. 8°/100 ft.* 6 5/8 Reg
*Estimated

Mechanical and electrical connections and interface to SureShot™ MWD

  • Resistivity sub is a node on the SureShot™ RS-485 bus

Power requirements

  • Low operating power for maximum battery life
  • Designed to run on 2x/3x batteries (10 cell DD) or 0x/1x/2x battery and turbine alternator

Tool Programming and Data Dump port

  • Hatch cover for easy access via an intrinsically safe connection to allow tool programming and memory dump. Memory data dumps and tool programming can also be performed when the tool string is disconnected from the resistivity via the tool string lower end.

32 MB integrated FLASH memory

Product Specifications

Environmental

Operating Temperature 0° to 347°F (0° to 150°C; 175°C option)
Pressure 20,000 psi (138 MPa)

Compensated Resistivity Measurements

FrequencyMeasurementRangeAccuracy
2 MHz Phase Difference 0.1 - 3,000 ohm-m ±1% [0.1 - 50 ohm-m]
±0.5 mmho/m [above 50 ohm-m]
Amplitude Ratio 0.1 - 500 ohm-m ±2% [0.1 - 25 ohm-m]
±1.0 mmho/m [above 25 ohm-m]
400 kHz Phase Difference 0.1 - 1,000 ohm-m ±1% [0.1 - 25 ohm-m]
±1.0 mmho/m [above 25 ohm-m]
Amplitude Ratio 0.1 - 200 ohm-m ±5% [0.1 - 10 ohm-m]
±5.0 mmho/m [above 10 ohm-m]

Transmitter / Receiver Spacing

 Measurement Point 
 UH DH
 T1T2*R1R2T3*T4
in. -36.00 -22.50 -4.25 +4.25 +22.50 +36.00
mm -914.4 -571.5 -107.9 +107.9 +571.5 +914.4
* Not included in 3.5 in. size

Depth of Investigation, Vertical Resolution

R1 = 1 ohm-m
RX0 = 0.5 ohm-m		Depth of InvestigationVertical Resolution**
Short Spacing RadiusLong Spacing Radius
2 MHz Phase 21 in. (533 mm) 28 in. (711 mm) 8 in. (203 mm)
400 kHz Phase 30 in. (726 mm) 39 in. (991 mm) 12 in. (305 mm)
2 MHz Amplitude 34 in. (866 mm) 44 in. (1,118 mm) 8 in. (203 mm)
400 kHz Amplitude 52 in. (1,321 mm) 66 in. (1,676 mm) 12 in. (305 mm)
R1 = 10 ohm-m
RX0 = 0.5 ohm-m		Depth of InvestigationVertical Resolution**
Short Spacing RadiusLong Spacing Radius
2 MHz Phase 26 in. (660 mm) 37 in. (940 mm) 8 in. (203 mm)
400 kHz Phase 36 in. (914 mm) 49 in. (1,245 mm) 12 in. (305 mm)
2 MHz Amplitude 40 in. (1,016 mm) 53 in. (1,346 mm) 8 in. (203 mm)
400 kHz Amplitude 60 in. (1,524 mm) 76 in. (1,930 mm) 12 in. (305 mm)
** 90% response in conductive beds
WPRTM and Sure ShotTM are trademarks of APS Technology