	Minette Consulting
		35 Years of Excellence in Nuclear Petrophysics

Contact Information Consulting MWD Gamma Calibration, Software and Training About Minette Consulting

1
	Calibrate your probe tool to API Standards

2
		Apply Collar and Environmental Corrections to your probe measurements

		3
			Train Your Staff In Calibrating, Maintaining, And Running MWD Gamma Tools

Gamma Ray Calibrator by Minette Consulting

Minette Consulting provides a gamma calibrator directly tied into the API test pits. Using this calibrator, one can, in less than half an hour, obtain an API calibration for the probe. No more relying on pre-set calibrations from the factory that become obsolete as the tool is run downhole repeatedly. Rather, the accuracy of your tool is put in your hands.

In addition, spreadsheets are provided that allow for the easy calculation and tracing of the API/cps ratios. You will be able to easily compare before and after calibration, and track tool histories with a few clicks of the mouse.

You can see how easy this is to use from our Calibration Calculation Example.

Even a perfectly calibrated probe will not give the right formation API values when run downhole. A good calibration is an important part of the puzzle, but cannot guarantee a good log by itself. One has to take into account the very complex environment in which the tool is run. That is where the Minette Consulting Environmental Calibration Software takes over.

Collar and Environmental Corrections

A number of different factors affect the tool response. One of the biggest and most obvious is the effect of the drill collar. Even half an inch of steel will absorb a significant fraction of the gamma rays. For this reason, drill collar correction curves are developed to correct for the effect of drill collars.

Several companies have developed these corrections, and they provide corrections that are in the ball park for a nominal collar. Minette Consulting’s corrections are unique in that they allow the customer to correct for non-standard drill collar weights.

But, the drill collar is only one of many factors affecting the response. In addition to the drill collar, there is the borehole environment which includes:

1) Mud Type and Weight

2) Borehole Size

3) Centering/Eccentering

4) Presence of Radioactive Potassium in the Mud.

5) Effect of Collar OD and ID on the mud response

After extensive efforts, Minette Consulting is now able to provide the most complete corrections in the industry, in accord with the most stringent specifications. As you can see, the range of borehole sizes mud densities, and types of muds meets or exceeds any correction algorithm that is provided by any service company.

Examples of the mud weight correction and mud radioactivity corrections give a picture of how the correction works.

A log example is also available to show the effects of calibration and correction on the log.

These corrections are available through the Benchtree receiver software.

Available Training

Gamma Technician 1

1) Basic Theory of Gamma Ray Logging

2) Discussion of the use of calibration in logging

3) Demonstration of Calibration Technique (including determination of the calibration factor with an Excel spreadsheet provided with the calibrator.)

4) Achievement of the learning objective will be shown by a successful supervised calibration of a tool using the techniques taught in the class

5) A certificate of training will be provided by Minette Consulting upon successful completion of the objectives of the training.

Gamma Technician 2

1) Achieved the learning objectives of Gamma Technician 1

2) Basic Theory of Gamma Ray Detection

3) Discussion of relevant details of the electronics involved in gamma ray detection

4) Discussion of the temperature effect on the spectrum

5) Discussion of the use of the plateau technique with gamma ray high voltages.

6) Demonstration of the use of a room temperature run and a 150C run to set the plateau.[1]

7) Achievement of the learning objective will be shown by a successful supervised setting of the discriminator point.

8) A certificate of training will be provided by Minette Consulting upon successful completion of the objectives of the training.

Gamma Supervisor 1

1) Achieved the learning objectives of Gamma Technician 1

2) Discussion of the changes in calibration during log

3) Use of a spread sheet to determine if tool changes are within acceptable parameters

4) Use of a spreadsheet to determine tool changes over time

5) Fleet maintenance from a measurement perspective

6) Achievement of the learning objective will be shown by a successful supervised use of maintenance software.

7) A certificate of training will be provided by Minette Consulting upon successful completion of the objectives of the training.

Gamma Supervisor 2

1) Achieved the learning objectives of Gamma Technician 2

2) Achieved the learning objectives of Gamma Supervisor 1

3) Use of spread sheets to determine changes in tool temperature responses

4) Identification of changes in plateaus as a quality indicator

5) Discussion of the use of plateaus to identify good and failing detectors

6) Fleet maintenance from a measurement perspective

7) Achievement of the learning objective will be shown by a successful supervised use of maintenance software.

8) A certificate of training will be provided by Minette Consulting upon successful completion of the objectives of the training.

Gamma Logging Engineer 1

1) Basic Theory of Gamma Ray Logging

2) Elementary Discussion of the Uses of Gamma Rays in Formation Evaluation

3) Discussion of the various factors that affect Gamma Ray Logging

4) Discussion of the means for correcting the log to eliminate the effect of these factors

5) Achievement of the learning objective will be shown by a successful supervised calibration of a tool using the techniques taught in the class

6) A certificate of training will be provided by Minette Consulting upon successful completion of the objectives of the training.

1 Plateau testing typically is done through changing the input high voltage value. Most providers of high voltage have straightforward techniques for doing this. Before a Gamma Technician II or Gamma Supervisor 2 training is run, a check with the manufacturer for their particular technique will be required.

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