A client in Gabon had encountered issues with debris in one of their wells located in a remote part of this West African country. The well in question was a 7” cased hole completion with approx. 165 ft (50m) of perforations. It was a critical component of the Koula production system being the only designated water injection well in the field.
However, some time ago the well lost injectivity and it was determined that something had filled the well to about 125 ft (38m) above the top of the perforations. At this time a Coiled Tubing (CT) cleanout was performed on the well, which uncovered about 85 ft (26m) of the completed interval.
Since then the Hold-Up Depth (HUD) in the well moved up so that only 16 ft (5m) of perforations were above the HUD. Now, the client wanted to perform a clean out from the current HUD.
As the field was located in the middle of the jungle it was crucial to consider the environmental aspects of the operation. Therefore, the client decided to use Welltec’s Well Cleaner® Power Suction Tool (PST) which would render a very low footprint.
Internationally this client had adopted Welltec’s solutions a long time ago, but this was the first time they applied them in Gabon. The PST was run in the hole to a depth of 5,771 ft (1,759m) where it was activated.
Over 18 successful runs, using up to six bailers per run, the PST recovered about 2,700 lbs (1,225 kg) of debris from the well. Unfortunately, the intervention confirmed that the well was refilling with debris during the clean out process.
The HUD did not change significantly despite successfully recovering large amounts of fill. This provided valuable information for the operator to further diagnose the cause and initiate appropriate measures.
The PST demonstrated excellent recovery rates with about 165 lbs of mud and sand per run. Switching to the e-line solution ensured a low footprint operation as only two people were mobilized with lightweight equipment, which was essential for the client.
The well site supervisor was very pleased with Welltec’s performance and they are now looking to adopt more Welltec® intervention solutions in order to reduce cost and time on other fields.
