MWD/LWD Systems

MWD System Specifications & Features

Compass’ MWD System is fully retrievable and can be re-run without tripping, reducing lost-in-hole risk. The tool has a long downhole life and is low maintenance, as well as having long battery life and low power consumption. Programmable surface and downhole systems provide reliable, accurate data to meet specific drilling conditions, while user-friendly operating software provides high-level filtering and pulse detection with clear readout on the rig floor.
Modular MWD System Overview
Available Sensors Directional, Gamma, Tool Temperature
Tool Configuration UBHO Sub (muleshoe) and probe
Tool O.D. (Available) 3-1/2” to 9-1/2”
Max Dogleg Severity 109° / 100 ft
Max Operating Temp 175° C (347° F)
Pressure Drop Across Tool Flow loop / calculated (water): 118 PSI
Max Hydrostatic Pressure 20,000 PSI
Flow Rate 70 ft/sec Low as 50 gpm (2.2” collar I.D.) Up to 1200 gpm (3-1/4” collar I.D.)
System Operation
Telemetry Type Positive mud pulse
Survey Transmission Time 90 seconds
Tool Face Update Rate 17 seconds average
Absolute Accuracies
Gravity Tool Face +/- 0.05° to +/- 3.0°, Programmable
Pointing Accuracy 0.15° = 2 ft per 1,000 ft displacement
Magnetic Tool Face +/- 0.05° to +/- 3.0°, Programmable
Azimuth +/- 0.1° (inclination > 5°)
Inclination +/- 0.1°
Crossover to High Side Tool Fa Programmable to any value desired (5° is typical)
Repeatability Inclination +/- 0.05° Azimuth +/- 0.05°
Readout Resolution Inclination 0.1° Azimuth 0.1° Tool Face 1°
Gamma Sample Rate One per 1.8 seconds measured 20 per minute in downhole memory. Programmable.
Gamma Memory Capacity 120 - 600 hours as function of program
Tool Dimensions
Directional Only 31 ft / 197 lb
Directional + Gamma 35.6 ft / 229 lb
Tool O.D. 1-7/8”

Compass Slim Hole MWD System

Tool Dimensions
  Length Weight
Directional Only 23.1 ft 78 lb
Directional + Gamma 23.1 ft 83 lb
Tool O.D. 1-3/8”
Modular MWD System Overview
Available Sensors Directional, Gamma Ray, Tool Temperature
Tool Configuration UBHO Sub (muleshoe) and probe
Tool O.D. (Available) 2-7/8”, 3-1/2”, 4-3/4”
Max Dogleg Severity 109° / 100 ft
Max Operating Temp 175° C (347° F)
Max Hydrostatic Pressure 25,000 PSI
Flow Rate 75 - 150 gpm (2-1/5” Collar I.D.)
System Operation
Telemetry Type Positive mud pulse
Survey Transmission Time 90 seconds
Tool Face Update Rate 17 seconds average
Absolute Accuracies
Gravity Tool Face +/- 0.05° to +/- 3.0°, Programmable
Pointing Accuracy 0.15° = 2 ft per 1,000 ft displacement
Magnetic Tool Face +/- 0.05° to +/- 3.0°, Programmable
Azimuth +/- 0.1° (inclination > 5°)
Inclination +/- 0.1°
Crossover to High Side Tool Face Programmable to any value desired (5° is typical)
Repeatability Inclination +/- 0.05° Azimuth +/- 0.05°
Readout Resolution Inclination 0.1°
Azimuth 0.1°
Tool Face 1°
Gamma Sample Rate One per 1.8 seconds measured 20 per minute in downhole memory. Programmable.
Gamma Memory Capacity 120 - 600 hours as function of program

Compass’ own Slim Hole MWD System is capable of providing Directional and Gamma Ray services in many types of wells, including short radius wells, at build rates not previously available through conventional MWD technology. It is the perfect tool for re-entry of wells where small production strings are used.
For deeper drilling applications, the tool will facilitate keeping pressure losses to a minimum and flow to a maximum, for better cleaning and cooling. The tool has a long downhole life and is low maintenance, which is complemented by its long battery life and low power consumption. It is fully retrievable and increases efficiency by saving time and money by eliminating pipe trips.

Directional Module

Compass utilizes sensor technology to provide a digitized output directional measurement solution. The sensor is designed to allow direct connection to a microprocessor based data acquisition system via dedicated serial interface connections.

Description

The Directional Module consists of three axis magnetometer, three single axis accelerometers, and associated electronics which are mounted on a rigid one piece chassis. The power supply is designed to operate off of DC power source Lithium Battery pack.

Tool Dimensions
Tool Type Length Weight
Kinte˝ 80” / 2.03 m 37 lb / 16.8 kg
Directional Module Specifications
Inclination ± 0.10 degrees, 3 sigma
Azimuth ± 0.25 degrees, 3 sigma
Tool Face Accuracy ± 1.0 degrees
Max Temperature 175° C (350° F) (150° C by request)
Max Hydrostatic Pressure 20,000 PSI (137.9 MPa)
Operating Voltage 18-32 V
Nominal Current 12 mA
Shock 1,000 g / 0.5 millisecond
Vibration 25g RMS 30-500 Hz Random 20g all axes

Features

  • Consumes minimal power, meeting the downhole environment requirements
  • Calibration data is provided with each unit

Compass Stepper Pulser

Description

The Compass Positive Stepper Pulser generates a sequence of pressure increment pulses in the circulating system, enabling the transmission of MWD data recorded downhole to surface.

The tool is fully retrievable and replaceable, which saves rig time by eliminating pipe trips for directional equipment.
The Compass Pulser Module consists of 3 main sections: Pulser Driver, Oil Fill, and Helix End.

The pulser allows mud flow to be restricted, creating a pressure differential by way of a main orifice poppet/orifice assembly. The movement of the main poppet in and out of the orifice creates an increase in pressure. The two factors that greatly affect poppet movement are the operation of the electrical section of the module and the fluid pressure on the compensation membrane.

Features

Simple to operate under a wide range of flow rates

Operable in lost circulation material concentrations of 30-50 lb/bbl medium nut plug

Servo technology for faster data rates, stronger signal, and superior anti-jamming capabilities for reliable data transmission in difficult drilling

Exceptionally power-efficient

Compass Stepper Pulser Specifications

Min Flow Rate 35 gpm (8 L/sec) in water
Max Flow Rate 1,100 gpm (67 L/sec) in water
Max Operating Temp 175° C (350° F)
Max Hydrostatic Pressure 20,000 PSI (137.9 MPa)
Operating Voltage 20-29V
Nominal Current 12mA
Shock 1,000 g / 0.5 millisecond
Vibration 25g RMS 30-500 Hz Random
30g 50-300 Hz Sine
Mud Sand Content <1% recommended
Poppet Push Force >100 lbs
Compass Pulser Driver Specifications
Inputs Power: 18-30VDC
Pulse: 0-5VDC
Output Flow Switch: 0-5VDC
Pulse Mode Limit 2A
Non-Pulsing Mode (quiescent) 4mA
Power Consumption 300-350 hours of continuous pulsing per 29V Lithium Battery Stick
Poppet Closing Force 140-155lbs
Length & Weight w/o Signal Shaft 64.5 in (1,638 mm) / 34 lbs (15.4 kg)
Length & Weight w/ Signal Shaft 86.25 in (2,190 mm) / 44 lbs (19.9 kg)
Housing Diameter 1.875” is standard, but can be built in 1.75”
Housing Material BeCu
Temperature Rating -40 to 175°C Functional; 185°C Survivable
Pressure Rating 20,000 PSI

Battery Module Housing

Features

  • Components capable of withstanding the temperature rating without degradation or outgassing
  • Carefully controlled internal welds and solder joints
  • Assembly techniques specific for high temperature, high vibration, and high shock environments

Benefits

  • High Voltage: 3.6 to 3.9V per cell
  • Highest energy density of any power source
  • Can withstand temperatures up to 200° C
  • Capable of withstanding extreme amounts of shock and vibration
  • Manufacturing ensures high reliability and safety
Tool Dimensions
Tool Type Length Weight
Kinte˝ 68.9” / 1.77 m 28 lb / 12.7 kg

Description

Compass uses high-energy Lithium Thionyl Chloride double-D size batteries in a stack of eight with a 150° C (302° F) temperature rating. The cells are diode protected to prevent reverse power charges, and are protected by a 5 Amp fuse on the power line.
The battery pack will run an MWD system for over 150 hours at a standard pulse rate with a Tensor Pulser, and 80 hours with a gamma probe added. With an upgraded Compass Pulser, a battery pack will operate the MWD system for over 450 hours and over 300 hours with an added gamma probe.

The design of the system allows for the addition of a second battery pack that will be activated when the power of the first battery drops to a predetermined level to then activate the power draw on the second battery. This allows the operator to place the batteries in various positions in the MWD tool design.
This option allows the users to determine the optimum position of the directional module determined by magnetic spacing requirements. The use of flexible finned intermodule connectors allows multiple design options on the MWD system with the standards being to place the pulser on the bottom (required) and the gamma and directional module located at the optimum positions.

Gamma Module

Gamma ray tools record naturally occurring gamma rays in the formations adjacent to the wellbore. This nuclear measurement indicates the radioactive content of the formations. Effective in any environment, gamma ray tools are the standard device used for the correlation of logs in cased and open holes. Gamma ray tools use a super-sensitive, hermetically sealed Sodium Iodide Scintillator crystal and a ruggedized high temperature Photomultiplier for maximum log quality.

Applications

  • Depth determination
  • Depth correlation within and between wells
  • Lithology identification
  • Qualitative evaluation of shaliness
  • Qualitative evaluation of radioactive mineral deposits

Uses

  • Distinguish shales from non-shales
  • Estimate clay content in sands and limestones
  • Correlation of real-time data with offset logs to determine geologic location
  • Picking casing and coring point
  • Vibration (3 axis) 50-300 Hz Random
Tool Dimensions
Tool Type Length Weight
Kinte˝ 80” / 2.03 m 37 lb / 16.8 kg
  Standard Module Focused Module
Mechanical  
Diameter 1.36” w/o housing 1.875” w/ housing 1.30” w/o housing 1.875” w/ housing
Length (make up) 13.6” w/o housing 41” w/ housing 13.6” w/o housing 41” w/ housing
Weight 1.7 lb w/o housing 21 lb w/ housing 3 lb w/o housing 22.3 lb w/ housing
Operating Temp -60° C to 175° C (-77° F to 350° F) -60° C to 175° C (-77° F to 350° F)
Material BeCu BeCu
Pressure 20,000 PSI 20,000 PSI
Performance
Sensitivity 2.0 Counts per API w/o housing 1.7 Counts per API w/ housing 0.6 Counts per API
Accuracy +/- 10% to 175° C (350° F) +/- 10% to 175° C (350° F)
Resolution 6.8” 6.8”
Environmental
Survival Temp 200° C (400° F) 200° C (400° F)
Max Heat/Cool -15° C (5° F) / Minute -15° C (5° F) / Minute
Vibration (3 axis) 50-300 Hz Random 30 G
30 G
30 G
30 G
Shock (Z-axis) 500 G, 0.5 mS 500 G, 0.5 mS
Shock (Y-axis) 1,000 G, 0.5 mS 1,000 G, 0.5 mS
Power
Input Voltage 22-30V 22-30V
Input Current 14-18 mA 14-18 mA
Max Voltage 31.5V 31.5V
Output Signal
Pulse +5V to 0V, 2 (+/- 0.5)
+5V to 0V, 2 (+/- 0.5)
microseconds
microseconds