Debris extraction technology can validate well cleanness

Published 08.07.2015

How do you know that all the debris is removed from the well?

Bottom line, it is very difficult to ensure that all debris has been removed from the wellbore. During the displacement phase, two surface measurements can be used to check the cleanliness of the fluid.Whilst filtrating the completion fluid, the Solids Content and/or the Nephelometric Turbidity Units (NTUs) will be measured to check the cleanliness of the fluid and by extension the well. This does not always mean the wellbore is fully clear of all debris however.

Several downhole debris tools, including magnets, junk baskets and downhole filters, have been developed to give you the ability to capture any debris in-situ and transport it out of the wellbore. Used in conjunction with the optimum displacement train, pumping regimes and operational best practices they will aid in delivering a clean wellbore.

Dependent on your well characteristics I recommend the use of the downhole debris filter tool to capture any debris that may not be circulated out and to validate the cleanliness of the well.

The benefits of a Downhole Filter Tool

The tool is designed for capturing debris downhole and has two functions: Firstly performing a cleaning action by capturing large pieces of debris as you run in hole. Secondly, confirming the effectiveness of the displacement by filtering the fluid as you pull out of the hole.

It features a diverter cup that fits tightly to the ID of the casing, thus forcing all the fluid, and debris, to pass through the filter into a debris chamber. When the tool is returned to surface a quick check of the debris chamber can tell you if there is still the potential for more debris in the wellbore.

The visual inspection of the fluid at surface and debris collected in the filter will give an instant feedback on the cleanness of the wellbore.

Time saving 

Have you ever started the completion process just to find out that the wellbore is not clean and you have to do the displacement all over again? The use of a Downhole Filter Tool is an effective way to validate the well cleanliness to ensure successful running of the Completion and/or eliminate any production issues due to debris particulates left in the wellbore during the displacement.

You can run it individually or modularly as a part of a wellbore clean-up string. Since there are no restrictions on flow rate, due the large total flow area (TFA) through the tool, the operator can pump at the optimum flow rates whilst filtering the completion fluid.

Should you use a Downhole Filter Tool?

Debris extraction technology gives you various options on well cleaning and debris removal. The application at hand and the job requirements will dictate the level of cleanness needed. For the best result and the ability to validate the well cleanness precisely, a Downhole Filter Tool is an ideal solution to combat your downhole debris issues.

Topics: Wellbore CleanUp

By: Stephen Mair

Stephen has over a decade experience in WellBore CleanUp (WBCU) activities ranging from authoring industry best practices to WBCU research and development projects. With experience in various global locations (North Sea, Europe, Africa & Alaska) he has been involved in introducing the next generation of mechanical & software solutions to meet today’s WBCU challenges.

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