The eXRES project deals with the development of new technology for real-time logging of formation resistivity for our core drilling equipment, aimed at CCS

The eXRES external resistivity tool for Logging While Coring
The global need to reduce greenhouse effects from CO₂ emission is a fundamental aspect of the
green shift. Carbon Capture and Storage (CCS) is one of the most important solutions to reduction
of CO₂ in the atmosphere. In CCS projects, the captured CO₂ gas will be injected in an underground
reservoir. It is essential to document the geological properties of the reservoir where the CO₂ will
be injected. Porosity, permeability, volumes, and potential CO₂ injection rates are vital parameters
to determine the suitability of the reservoir. Core samples are the primary source of information for
determining the geological properties of the CO₂ reservoir and the sealing formations.
CoreAll have developed the world’s first instrumented coring system. The Intelligent Coring System
(ICS) features formation evaluation logging sensors and downhole diagnostics with real time data
transmission to surface. The Logging While Coring (LWC) module includes core resistivity and
gamma ray measurements with downhole inclination, vibrations, and core jam indication.
CoreAll have also developed the CoDril™ downhole convertible drill bit, which enables drilling and
coring with the same downhole tool, saving substantial tripping time, cost, and carbon footprint.
Analysis of a recently drilled CCS exploration well in South Louisiana showed a total of 33 runs in
the reservoir section, 19 coring runs and 14 drilling runs. A conventional coring system was used.
The total number of roundtrips was 33. With the CoreAll CoDril™ downhole convertible drill bit, all
14 drill-ahead sections could be combined with cutting the following core, and 14 roundtrips saved.
For an introduction to the CoreAll Intelligent Coring System, please refer to product video:

Formation Resistivity is one of two fundamental Formation Evaluation measurements that are
essential for real-time decision process while coring. The existing Core Resistivity sensor measures
across the core and the limitation is that it only measures while coring, and not while drilling. For
the CoDril™ concept to be of full value, an external resistivity measurement is required. Formation
Resistivity can then be provided continuously, both in coring and drilling modes. The eXRES project
is consequently a key enabler for the disruptive CoDril™ technology to reach its full potential.

Environmental Effect:
The eXRES technology will have a direct positive environmental effect because of reduced
operation time to drill exploration wells that include coring. By utilizing the full CoreAll suite of
technologies, the Intelligent Coring System with the Logging While Coring and the CoDril™
downhole convertible drill bit, and including the planned eXRES External Resistivity sensor, the
average time saving of 3-6 days per CCS exploration well is expected, (assuming 3 cores). It is
estimated that a drilling rig is using average 16 tonnes of diesel per day, which is equivalent to 50
tonnes CO₂-equivalents and 19kg NOx gas. Consequently, 3-6 days saved drilling time gives a
reduction of 150-300 tonnes CO₂-equivalents and 57-114 kg NOx gas per well. On top of this, the
CoreAll technology will contribute to massive reductions of CO₂ gas in the atmosphere, which is
vital for the green shift.

The eXRES external resistivity tool will be integrated in the existing LWC tool as shown in the figure below.
eXRES External Resistivity tool, integrated in the LWC: