Unlocking the Power of Multi-Sensor Core Logging with Core Technical Services

CoreDNA Solution

Together with our partners at Epslog

This technology brings core analysis into the 21st century. High resolution data is rapidly acquired and combined to create and define trans-disciplinary distinct facies types enabling highly targeted sampling for all subsequent, standard core analysis.

This allows targeted sampling both for routine core analysis and most importantly for advanced studies including special core analysis (SCAL) and geomechanics.

How?

Rapid high resolution core logs are delivered to equip core specialists with trans-disciplinary & quantitative core data right after barrel opening.

Challenge:

Before slabbing, no direct access to suitable surface to take photography or conduct measurements.

Solution:

Disruptive innovation based on the “scratch test” technology to surgically open a window at the surface of the core. One unique equipment from core preparation, data collection down to integration.

Sample Preperation

Smooth flat surface on full cores with PDC cutters

No prior sample preparation required

3 cm large window max, machined by PDC cutters with sub-millimetric cuts
Level @ µm scale;
Only 3mm thick layer of material removed (on 4 inches diameter core)
Preserve cores for plugging and slabbing
Suitable for a comprehensive series of continuous measurements

UHR Photo

Core Photo (Vis &UV) ~1.8µm/px

XRF

Elemental Composition

HR Photo

Core Photo (Vis &UV) ~35µm/px

Laser Scan

Grain size index

Strength Test

UCS

Probe Perm

Permeability Index

Ultrasonic Vp&Vs

Sonic Logs

CoreDNA Workflow

CoreDNA Core preparation:

The first step in the core analysis services consists in creating a perfectly levelled surface along the rock samples with micrometer accuracy and designed to prevent any mechanical damage to the samples. Depending on its width, it is either called MiniSlab (4cm) or SurgiCut (1cm) and is a pre-requisite to run any other test. MiniSlab and SurgiCut can be performed on samples of any shape and size, from sidewall plugs, and slabbed cores to whole cores before slabbing. This preparation procedure includes the panoramic standard groove photography (35µm/px).

CoreDNA Rock Strength Profile :

A continuous high-resolution profile of rock strength is obtained from the analysis of several successive scratches that shear surgical predetermined quantities of rock during which the pressure at which the rock fails is constantly recorded at high resolution. This process is equivalent to conducting a succession of Uniaxial Compressive Strength. The large series of tests (at least 8 conducted in the same groove) confers robustness, coherence and reproducibility to the test results.The existence of the SURGICUT or MiniSlab is a prerequisite

CoreDNA Laser 3D Scan :

Laser scanning of the SURGICUT enables the high-definition mapping of its topography. The analysis of the 3D scan performed with proprietary analysis is used to infer continuous profile of grain size index. Empirical proprietary equation is used to turn this profile into a robust high resolution permeability log; useful to characterize for instance robust net reservoir value in highly laminated formations.

In carbonate rock, this 3D scan is used to characterize the presence of pores larger than a couple of tens of microns.

CoreDNA pXRF Logging:

Continuous logs of elemental composition for element above Mg is inferred by using a portable XRF system. Sampling frequency is at least one measurement point every 3 cm. It provides a very rapid insight about modification of the mineralogy along the core axis. Combined with other measurements, it provides an essential geological input for rapid lithofacies identification.

CoreDNA ULTRA HR IMAGES:

Panoramic Image at the resolution of thin sections: Ultra-high-definition core pictures (1.8um/pixel) of the SURGICUT are taken under natural or UV light. Successive panoramic pictures of 5cm large over 7mm width are generated. This resolution close to the one used in thin section reveals unseen features of the rock that can be the base of a sedimentological description. They are also considered as untemporal unique archive of the rock samples. They can be used for confirming grain size indexes for clastic reservoir.

CoreDNA Report :

Interactive hyperlinked PDF

All data stored in one place
Detailed description per meter section
Hyperlinks to navigate in or to the core photos
General core overview or centimetric description

CoreDNA Optional Extras

CoreDNA Add-on Sedimentology:

Sedimentological conversion of GSD data: Raw micron-scaled grain size distribution data from CoreDNA laser scan is uploaded into Epslog proprietary 'LithoLog' software. This involves 2 steps; the first being a QC of the raw GSD data, with corrections applied if necessary; The second step converts the continuous cm-scale micron-scaled grain size measurement into a bedding-scale Wentworth grain size curve suitable for transposing onto a core description proforma. Curve data is provided for: 1.) Continuous cm-scale corrected laser scan GSD (microns), 2.) Bedding-corrected Wentworth grain size data (output as phi for transposition onto Wentworth logging sheets). At no extra cost, the curves can be directly transferred onto logging proforma sheets (using WellCAD and delivered in scaled PDF format), ready for immediate use at the core store.

CoreDNA Add-on Probe Perm:

Steady state probe permeameter system including 3 flow meters from 0.08ml/min to 10000 ml/min in order to assess sample permeability to gas. Pressure and flows are measured continuously at high frequency. Sampling frequency: every 3cm (can be increased if requested).

CoreDNA Add-on Ultrasonic P&S wave velocities:

The sonic test measures the travel time of an elastic P&S wave between two ultrasonic probes of nominal frequency of 50kHz. Standard deliverables consist of high-resolution continuous profiles of compressional and shear ultrasonic velocities. The method can be applied on complete sections of whole cores, even on core sections unsuitable for plugging. Ultrasonic velocities measured on core are used to calculate continuous profiles of dynamic Poisson ratio and are combined with density profiles obtained from CT-scan images to derive profiles of the dynamic Young modulus.

CoreDNA Add-on: UV images of minislab

(35μm/px)

CoreDNA Add-on Powder Collection:

Rock powder is a by-product of the SURGICUT. Because the volume density (volume per unit of length) is kept constant along the SURGICUT length (along the core axis), the powder is evenly sampled along the core. This powder produces ad-hoc specimen to conduct elemental or mineralogical study with XRF, XRD or FTIR analysis. The FTIR analysis is particularly attractive as they produce results extremely rapidly. The existence of the SURGICUT is a prerequisite.

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If you have any additional questions don't hesitate to get in touch and one of our specialists will be happy to help