Fracture Evaluation

Everything You
Need to Know

• What are CARBO Fracture Evaluation Technologies and what do they do?

  CARBO offers CARBONRT for near wellbore proppant detection. It enables proppant placement evaluation, it can measure propped frac height in vertical wells, frac initiation, connectivity and cluster efficiency in horizontal and deviated wells, annular fill in gravel pack and fracpacks and evaluation of frac diversion techniques. CARBONRT has also been used to trace cement and sealing gels for placement evaluation of cement repair and conformance treatments.

• What is CARBONRT, what are the benefits and how does it work?

  CARBONRT incorporates an inert tracer during the ceramic proppant manufacturing process to make it detectable. The inert tracer has a high neutron capture cross section which is detectable with standard, cost-effective neutron logging tools. The interpretation is made comparing the response of pre and post proppant placement neutron log runs. Three robust independent interpretation methods are available assessing neutron counts, Sigma, and elemental analysis yields.

  Key benefits of the CARBONRT technology are its reduced HSE footprint, simplified logistics, handling and disposal derived from its inert nature, as compared to the inconvenience of using conventional Radio Active (RA) tracers.

  Another key benefit is its permanent nature, that makes it detectable throughout the life of the well, vs. the limited half life detection period of conventional RA tracers.

• What proppant types and sizes are CARBONRT available in?

  CARBONRT can be manufactured in any of CARBO’s vast lineup of proppant types and sizes.

• Does the tracer change the properties of the base proppant? Does the use of CARBONRT require a new MSDS sheet?

  No.  CARBONRT is a safe, environmentally friendly material that contains only minor amounts of tracer.  There is no change to the mechanical properties or the MSDS.

• Does CARBONRT have a “half life”? Will CARBONRT decay and lose its effectiveness over time?

  No.  The tracer is a permanent part of the pellet, does not decay, and cannot be removed.  It can be logged any time in the future, and there is no limit on how long or how many times it may be logged.

• How deep into the reservoir can CARBONRT proppant be detected?

  Similar to RA tracers, detection limits are <2 feet.

• Why should I use CARBONRT?

  It is safe, environmentally friendly, and effective.  There is no concern for regulators, landholders, or wellsite personnel if some amount of CARBONRT is left on location or flows back from the well, as opposed to radioactive tracers which have come under increased scrutiny.  Since CARBONRT is uniformly contained in every proppant pellet, there is no chance of segregation as compared to using traditional RA tracers in which a small volume of highly radioactive particles are blended into massive treatments.

• Are proprietary logs required to detect CARBONRT?

  No.  Standard neutron logging tools run at standard speeds are used to detect CARBONRT.  Compensated Neutron or Pulsed Neutron tools run in Sigma or Spectral mode can be used. Pulsed tools are preferred as they are slimmer and can provide at least two interpretation methods simultaneously (counts and Sigma, or counts and elemental yields) are preferred. Newest tools that can be run in Sigma and Spectral mode in a single pass are preferred as the can provide the three interpretation methods simultaneously: counts, sigma and elemental yields.

• Who does the log interpretation?

  CARBO will do it using the completion and logging data provided by the operator en service company.

• Does the well need to be logged right away?

  No, CARBONRT does not have a half life and is detectable throughout the life of the well.  This may be ideal when evaluating restimulation potential several years following the initial frac.  [After this time, traditional radioactive tracers are typically undetectable.]

• How does the logging company know what to look for, what settings to use, how many passes to make, etc?

  CARBO has developed a set of operational guidelines to be given to the operating and logging companies.  In addition, analysis procedures will be given to the logging analyst and CARBO experts will be available to work with the analyst during the interpretation.