Downhole Jetting Tool takes samples, restores production

Water shut-off
CLE.NOR.16.12.V1 Well Cleaner Downhole Jetting Tool takes samples, restores production compressor
  • Well type Oil producer
  • Location Norway


A client in Norway had a well that died, and left them with no injectivity or productivity, after only producing ~1/2 well volume after re-completion.

It was suspected that the well and its screens had been filled up and clogged by particles from the completion fluid that was initially placed inside and outside the screens.

Client wanted to get a sample of fill and fluid blocking the screens and from that find suitable chemicals to flush screens with to re-open flow path from reservoir.

Welltec proposed an approach that would fulfill clients wishes in two runs:
- Sample both solids and liquids at target depth (TD) using Well Cleaner® Downhole Jetting Tool (DJT) with new valve setup.

- Convey suitable chemicals down to TD with Well Cleaner DJT, and flush the screens with chemical and well fluid to re-open screens.

New approaches

A full test to find the best setup with pumps, valves and flappers was done in Bergen to show that we could sample and preserve both solids and liquids from TD to surface.

Introducing the Well Cleaner DJT as a sampling tool of both liquid and solids in separated chambers.

Introducing the Well Cleaner DJT to be a safe and efficient tool to convey chemicals to be precisely spotted at screens to flush and re-open them.


The DJT was filled with 6,8 liters of the surfactant “Safe Surf ” that was suited to dissolve the emulsion collected in previous run. RIH to HUD. Started the DJT as deep as possible as the surfactant was lighter than well fluid to let it migrate upwards together with DJT. Kept the DJT running while moving over the screens, doing stations every 3 meters lasting two minutes each to let the penetrate properly.

Repeated sequence twice while flushing well fluid mixed with the surfactant.


Well Cleaner DJT proved to be able to sample and preserve both solids and liquids in separated chambers from TD to surface.

Using the Well Cleaner DJT to spot and flush suitable chemicals right in front of screens, with no injectivity, proved to re-open screens and get the well back on production.

The DJT reduced the volumes of chemicals needed and saved the client from what they expected to me a much bigger clean out job.