AutoScan
The AutoScan is a unique measurement platform developed by NER for the detailed quantitative and efficient description of core properties. NER developed this non-destructive measurement system specifically for rock typing, plug selection, and well-log data calibration in order to optimize the use of core for reservoir characterization.
A detailed description of core properties and their correlations is made possible via the use of interchangeable probes for ultrasonic velocity (compressional and shear), complex electrical impedance, impulse hammer mechanical testing, gas permeability, composition (FTIR), and digital photography. Formation heterogeneity for each of these properties can be measured in a single setup on up to 4 meters (12 feet) of core using point measurements and surface scans. A high-precision computer-controlled XY gantry guided by a laser ranging device positions each probe at programmed locations and sample measurement intervals as small as 0.1 millimeter.
- Detailed core-based measurements for log calibration
- Rapid core screening for plug selection
- Quick determination of relationships among petrophysical properties
- Resistivity and FMI log calibration and interpretation
- Pretrophysical upscaling and high resolution model building
- Improved integration of well-log data and core lithology
- Mechanical profiling and strength prediction
- Positioning Repeatability, mm – ±0.01
- Accuracy, mm – 0.1
- XY table size, mm – 1350 x 750
- Active measurement area, mm – 990 x 530
- Laser Defect Scanner – ~1 mm spot size
Measurement Options for the AutoScan
Permeability
Permeability is measured using a steady-state gas injection technique. The steady state flow method is generally considered the most accurate method for probe permeametry, relying on fewer theoretical assumptions than pulse decay techniques. Permeabilities ranging from 0.1 millidarcies to 5 darcies are measured with the standard 4.0 mm permeability tip. In addition to the fully automatic mode, the measurement control and acquisition software allows user selection of pressure control or flow control based measurements. NER’s Smart-Flow technology allows the system to optimize measurement control parameters during the actual measurement to increase measurement speed and precision.
- User defined stability criterion for steady state permeability measurements.
- User customizable tip definitions and data acquisition parameters for individual samples and/or rock types.
- Automatic logging of depth, measurement time and measurement history, including complete pressure vs. flow history for each permeability measurement.
- Automatic pressure and flow selection.
- User definable pressure and flow limits.
- Fully combined with
- Range, mD 1-5000
- Flow Controllers, scc/min 0-500
- Pressure Transducers, kPa 0-345
Velocity
The Velocity Tip measures ultrasonic compressional and shear wave velocities. Since the Velocity Tip is fully integrated with the Permeability Tip, the two measurements can be made sequentially during the same scan. Both compressional and shear velocities can be measured in multiple orientations on the core, providing a means to quantify anisotropy in elastic properties.
See image below: The Combined Ultrasonic Velocity-Probe & Gas-Permeability Probe Assembly. Allows the measurement of permeability and velocity during a single scan, providing improved speed and data integration.
- Measures both compressional and shear velocities.
- Automated XY propagation directions for velocity measurements in two directions (standard).
- Optional continuous rotary actuated (0-180°) arbitrary angle for detailed anisotropy studies or for measurements on core from deviated wells.
- Easy waveform picking for velocity computations, with automatic waveform matching for computer-based pick refinement including attenuation effects. Ability to use either local or global reference waveforms for pick refinements.
- Short spacing option for smaller samples or applications requiring shorter propagation path.
- Fully combined with permeability probe allowing for simultaneous use of both probes.
Resistivity
The Resistivity Tip measures the spatial variability in electrical properties. The probe is a true four-electrode device, with an electrode pair located in the central cavity and an electrode pair configured as rings around the outside of the rubber tip. An integral temperature sensor allows for automatic correction for temperature effects on the measured resistivities.
- True 4-electrode resistivity measurements yield both amplitude and phase information while minimizing electrode polarization effects
- Contacting measurements made with sample submerged in brine bath providing a well-defined location and geometry of measurement.
- User selectable single frequency and frequency-sweep measurement modes
- Able to make measurements using a wide variety of brine concentrations (spanning fresh water to heavy brines).
- Standard Diameter (ID), mm – 7
- Standard Resistivity Range, ohm-m – 0.2-10,000
- Phase Resolution, degrees – 0.2
- Standard Frequency Range – 0.1 Hz – 100 kHz
Impulse Hammer
The Impulse Hammer Probe is used to characterize the variability of elastic stiffness and mechanical strength. The probe measures an elastic stiffness that in the elastic regime is dominated by Young’s modulus. The probe can be configured to produce an additional strength index as well. Unlike competing methods such as the scratch test, the Impulse Hammer Probe is non-destructive (only a millimeter scale indentation is made, even in soft materials). Measurement area size is 2 mm with typical measurement times of 10-15 seconds per point. The addition of the Impulse Hammer Probe provides a point measurement sensitive to mechanical properties that can be used to map variations in elastic stiffness and strength.
- Simultaneous measurement of both force and acceleration.
- Carbon fiber guide rod
- Exchangeable WC impact tip
- Automatic processing
Specifications
- Force Sensitivity – 100mV/lbf
- Acceleration Sensitivity – 100mV/g
- Frequency range – 1-8000Hz
FTIR
The addition of an FTIR Probe provides a measurement sensitive to chemical composition. The spectrometer is configured as a non-contacting probe that measures IR reflectance over a broad spectral range. Measurement spot size is 3 mm with typical point measurement times on rock samples of 20–40 seconds. The FTIR Probe option includes a infrared spectrometer, quick connect mounting hardware, data acquisition software, and custom spectral data viewing and support software that display data in real time.
- Large Spot Size – 3mm
- Spectral Range – 1330–26700 nm
- Integrated video camera and display
The AutoScan can be outfitted with a digital camera and integrated LED lighting for photographic documentation of samples. The Camera option enables quick and accurate photo-documentation of samples and the integration of core photographs that are automatically depth registered with the AutoScan data. Key features include:
- Adjustable LED lighting
- Permanently mounted for simultaneous use with all available AutoScan tips.
- Auto-stitching and montage modes
- Automatic depth registration
- Auto-background correction
- Auto-focus based on entered sample height
DataMiner software allows for interactive plotting and data analysis, including petrophysical modeling, geostatistical model building, and rock type identification through cluster analysis. Simple ASCII data files can be exported in common formats for specialized processing.
- Quick loading of all AutoScan data types
- Zoom and scroll
- Interactive crossplots with point selection and highlighting
- Ternary plots
- Multi property cluster analysis
- Cluster group based histograms
- Importing user supplied data including plug measurements, CT images, and log data
- Depth shifting
- Smoothing and filtering
- Interpolation
- Simple data export to other programs
