A new polymer technology successfully implemented in one of offshore oil well.
The technique uses water-soluble polymers and microgels having a strong tendency to adsorb on the surface of the rock, thus forming a protective film to prevent the erosion process.
Many wells in this area are facing sand problems due to reservoir depletion and water entries. To avoid critical problem connected to sand production the most common action has been so far to reduce production rates by choking down the wells and recompleting the wells utilizing downhole sand-control solutions (sand-screens).
The common problem of sand-screen completed wells is mechanical screen damage due to high abrasive reservoir fluid velocity resulting resuming and even accelerating sand production to the surface.
Damaged section of sand-screens has been identified by utilizing sand-detection logging technique ran in hole by wireline and polymer sand consolidation treatment selectively placed by CTU across target zone.
Executed chemical treatment consist of injecting of water soluble polymers with the main objective to form an adsorbed polymer layer on the surface of the rock, thus providing sand/fine stabilization.
The products also have RPM properties (Relative Permeability Modifiers), i.e. they affect little oil relative permeability while reducing the relative permeability to water.
Field trial have been executed with the following results:
Treatments were successful in stopping sand production
No water production observed over the few month after the treatment
The treatment helps to restore the production of the well shut-in more then 6 month due to extensive sand production.