Defoamers are highly cost efficient, working at injection rates of just a few parts per million.
Following fracturing and cleanout, an operator in the Bakken decided not to flow back its wells before starting production, and the accumulation of debris, chemicals, water, sand, and formation solids led to the formation of a stubborn polymer foam at the four-well pad. The foam triggered high-level alarms in the separation vessels, which shut in the wellheads and stopped production until the alarms were manually reset and the wellheads were manually reopened. When a polypropylene glycol–based defoamer and emulsion breakers did not resolve the issue, the operator needed a new solution to eradicate the foam and stop the alarms, which were being triggered multiple times per day.
Because the typical solutions had not proven effective at removing the foam, SLB took a multidisciplinary approach and relied on the deep expertise of its subject matter experts to quickly find an alternative chemistry. SLB subject matter experts suggested trying the D206 defoamer, which is a latex-based defoamer specifically developed to break down polymer foams and is used in cementing operations. An onsite test demonstrated that the D206 defoamer quickly eradicated the foam. In all, it took the SLB team only 48 hours to find a chemical solution to resolve the Bakken operator’s issue.
The D206 defoamer was applied through direct chemical injection upstream of the vessels and via batch treatments as needed. This defoamer effectively prevented foam from forming as production fluids degassed within the vessels, and it successfully broke down the existing foam within the vessels. By mitigating the foam, the SLB team prevented further triggering of the high-level alarms and enabled the operator to promptly restore normal production operations.