“One size does not fit all when it comes to Snubbers! A shock/vibration isolator must be designed specifically for the device it is intended to protect. Our Snubber is more like the shock absorbers you see on off-road vehicles – compared to something on an urban car!”
Paul Sinclair, PhD, President, CBG
The purpose of a Gamma Snubber is to protect the Scintillator Crystal and Photomultiplier inside the Gamma tool from shock & vibration greater than their specification allows. This is the most common failure mode of all Gamma tools, and replacement of these components is a significant expense.
With the higher ROP’s common in modern horizontal drilling operations, and the drive to exploit harder and hotter rock formations, the survival of Gamma probes has become a priority.
Many service companies protect Gamma tools using a snubber designed almost 20 years ago for use with batteries, which is no longer acceptable! CBG Corporation always has the best interests of our customers at heart, so we got to work to find a solution.
Designed specifically for use with CBG Gamma tools, but also available in versions for heavier directional units and batteries, the CBG Snubber more effectively minimizes the shock and vibration that is transmitted through the MWD string to the Gamma tool. It has less than 1/4 the spring rate of the most commonly used snubber currently on the market and more than four times the range of relative motion.
In addition, the CBG Snubber uses a unique high-temperature rubber compound that has built-in damping, so that shocks are quickly attenuated.
Independent labs Professional Testing Inc. in Austin, Texas, performed side- by-side HALT tests on the CBG product, a standard “battery snubber”, and a new snubber from a competitor. The graphs are from their final report. How do we compare?
On the vertical axis of the graph is the vibration experienced by the Gamma tool, versus the level applied to the Snubber/Gamma assembly. We used a broadband random spectrum of vibration typical of BHA motion, measured in Grms. The new CBG design transmits only 1/6th of the shock and vibration, compared to 1/3rd for the standard snubber (Y). The new competitors’ snubber (X) is even worse, hitting the Gamma tool with almost 1⁄2 the bad shocks! Apparently, this new product was designed to prevent snubber failure more than to protect the Gamma tool.
The CBG product really shines when the test is repeated at high temperature. The standard snubber (Y) starts to completely fail at only 40G levels due to limited range of motion, and the other competing product (X) begins to pass 70% of the vibration to the Gamma tool at any vibration level! Notice that the CBG Snubber displays constant performance at all levels and at all temperatures.
With test results like these, it is easy to see why Gamma tool failures have been more common in the tough drilling conditions we face, using battery snubbers. Fortunately, there is now a solution available – from CBG!
Ask us about this product and also versions designed for the Directional Unit (to protect your expensive accelerometers) and for batteries (to reduce the risk of catastrophic failures).