On the far end of the flowback spectrum is a completion process called soakback. Instead of allowing the well to flow back right after completion, some operators are forced to shut in their wells for months at a time until takeaway capacity is available. The completion fluids then soak into the shale rock. What happens during that process is still being debated, but flowback analysis may provide some answers.
Robert Hawkes, the corporate director of reservoir solutions at Trican Well Service, has been studying the issue for the past few years and collaborates with the research team at the University of Alberta. He is pushing a controversial theory, which holds that, in many cases, the water used in stimulation treatments is not a damaging mechanism for shale reservoirs. Hawkes said his idea is supported by a number of Canadian operators that have recently come to the same conclusion.
Among the most common fears is that the water swells the clays inside the shale, which then leads to fracture damage. “Yet, in the past 15 years, we’ve been putting a ton of water in these same reservoirs and getting good results,” Hawkes said. He thinks such results have been possible because the mixed fabric of shale can tolerate vast volumes of water....
Letting It Soak In: Delaying Flowback Delivers Unique Results
Trent Jacobs, JPT Senior Technology Writer
01 December 2015