Beating rapid scale build-up

Challenge

Client has a small field in which most wells develop barium sulfate scale (BaSO4). The BaSO4 scale can build very rapidly, resulting in reduced production. The scale in the tubing can be cleaned with a bit-and-scraper run, but the scale in the perforation tunnels is not removed during this procedure.

The client wanted to try another method to remove the scale in the casing, as well as attempt to remove scale in the perforation tunnels.

• Depth: 5,200 ft (1,600 m)
• Formation: Sandstone

Solution

Remove scale and improve connectivity to the reservoir using electro-hydraulic stimulation technology.

• In conjunction with a workover, the tubing and bottom hole assembly were pulled.
• The well was cleaned with a bit-and-scraper before running BLUESPARK®, with all debris cleaned from the sump.
• The BLUESPARK® was deployed into the wellbore and 3 zones of perforations were treated, for a total of 52 feet.

Outcome

• The client ran back in the wellbore with tubing and discovered that the BLUESPARK® had created 11 feet of fill (in 7 inch casing).
• An analysis of the fill determined the presence of silica and clay, along with the BaSO4, confirming that the perf tunnels had been cleaned.
• Oil production increased from 78 b/d to 96 b/d (23% increase).
• Water production decreased 11%.