A five-well HTHP plug-and-abandonment campaign required high-density brines and cement spacers. An engineered alternative to Sodium Bromide reduced total campaign costs by 60% and individual well costs by up to 90%.
The Challenge
A series of five high-temperature, high-pressure plug-and-abandonment wells required kill fluids ranging from 9.04 to 12.61 ppg at temperatures up to 204°C. Standard Sodium Bromide brine at the required densities would have been extremely expensive — formates and heavier brines are typically leased rather than purchased due to cost.
The Approach
MI SWACO Drilling Fluid Specialist Andrew Bilton worked with the client to design an engineered alternative. Using DUO-VIS suspension agent, PTS-200 polymer temperature extender, SAFE-SCAV H2S scavenger, and M-I BAR barium sulphate weighting agent, the team blended a kill fluid that initially achieved 9.8 ppg with Sodium Chloride, then used M-I BAR additions to reach the required densities — avoiding the switch to expensive Sodium Bromide.
The Outcome
The engineered fluid system reduced costs on the 12.61 ppg well by approximately 90%, and total campaign costs by approximately 60%. The approach demonstrates how an engineered alternative to commodity brines can dramatically change the economics of plug-and-abandonment operations.