Q&A No. 713 - Are there any existing logging tools that have been successfully used to infer sand influx zones?

0 votes
Are there any existing logging tools that have been used to succesfully idenitfy zones of sand influx in a producing well? Although we will be inferring zones of high sanding tendencies from existing LWD data (in cased and perforated wells) there has been a challenge raised about the accuracy of such techniques if we perform an intervention and shut-off sanding zones based upon prior LWD data as opposed to 'making an in-situ' measurement to confirm sanding (and regardless of the inherent risk of such an in-situ measurement which is a considerable risk).

I am aware that some companies have used so called noise logs to determine sanding influx but this practice appears very rare and perhaps is only suitable under specific circumstances and well designs. Has anyone thought about (or indeed run) either some form of static or dynamic (well flowing) measurement to determine sanding? Or actually looked at this detail and in fact risk-assessed the log and then discounted it.
asked Apr 26, 2016 in COIN by Paul Cadogan (180 points)

2 Answers

0 votes
Hi Paul,

Interesting query. No experience in our company with noise logging for that purpose. I discussed your problem with a petrophysicist colleague and he pointed towards SPE papers #161712, 161983 and 162081, which discuss Spectral Noise Logging (SNL), albeit again not for the purpose of identifying sand production. My personal view is that it might work and a discussion with the service company would be useful.

My colleagues also suggested maybe one of the new cement bond logging techniques might help identifying weaker or sand producing formations.

Good luck,

Pieter Jagtenberg
answered Apr 28, 2016 by pieter jagtenberg (220 points)
Thank you for your response, Pieter
0 votes

Hi Paul,

Here's a response from one of our COIN registered non-members, Chris White.  

As a result of an extremely serious incident which I experienced many years ago on a SNS gas well, I would most strongly advise against deploying any logging tools on braided cable in a potentially solids-laden well stream environment. 

The logging cable is coated in pressure-retaining grease to which solids particles adhere. The cable exits the surface pressure control equipment via a set of flow tubes which have an internal diameter approximately 0.001” larger than the cable passing through it. The axial gap between cable and flow tube is filled with grease at a pressure above the wellhead pressure to provides a seal against well pressure.

Solid particles stuck to the cable grease will accumulate below the flow-tube and become jammed between cable and flow-tube. Because the cable is helically wound, the cable will start to twist as it is recovered from the well thus torqueing-up the cable and ultimately preventing the cable from passing through the flow-tubes, leaving cable and/or toolstring stuck across the Production Tree and downhole safety valve preventing them from closing.

In my case, ultimately the well was killed to allow the situation to be remediated, but not until a major incident had occurred resulting in serious personal injuries, loss of containment, damage to equipment, and loss of production.  Additionally, the logging cable had to be scrapped as the section that had been recovered before it became jammed had been torqued-up on the winch drum.

In Paul’s case the noise-log tools should be deployed as part of a memory toolstring on slickline or coil tubing, however if real-time surface read-out is required, or if the logging tools cannot be incorporated in a memory toolstring, then deployment should be via e-coil.

Hope this helps

Best regards

Chris White
Managing Director
Signspread Ltd.

answered Apr 29, 2016 by Fiona Curley (1,480 points)