By Heather Douglas
“Planning a refrack can often feel like being in a black box. There is little published information about refrack best practices and techniques, and even finding the locations of these wells can mean multiple searches. How can companies that are interested in refracks find the information it needs to achieve successful results?” Identify and Analyze the Best Fracs, published by DrillingInfo.com.
It’s the new ‘hot and sexy’ in Saskatchewan’s Bakken formation and is a trend that is sweeping across the Canadian shale industry. It’s called refracking, or restimulating, the rock to accelerate the rate of production and enhance the ultimate recovery of trapped hydrocarbons. The technique itself is nothing new. Engineers are schooled to identify aging, low-performance wells. For decades they have contracted service rigs to hit the wellbores with blasts of water and sand and thus reboot the flow of crude.
The magic arrived when these same engineers applied the procedure to horizontal wells and voila, something much more financially rewarding occurred. They managed to stretch the lifespan of these wells and, according to some experts, potentially extend the lifetime of the fields by a few decades. All this at a fraction of the cost of drilling the first well.
By refracking old shale wells in the Bakken, some operators believe they have revived the viability and profitability of portions of the entire field. Some even claim they have taken newly drilled, under-performing wells, refracktured them, and boosted production. This has the potential to position these clever operators with two- and three-fold more production with a minimal capital expenditure.
In 2014, it cost about $7.1 MM (US) to drill a Bakken well. That fell to $5.9 MM the following year. Some of these wells have now been refracked at a cost of approximately $1.25 MM each (nicely saving 75 per cent/well on drilling and completion expenses).
At first, the engineers were uncertain where to target the fracking fluid, then they got new software that removed the hit-or-miss nature of refracking and, when they tracked the economics, they saw their profits rise along with the huge increased in well performance.
According to Tim Leshchyshyn, founder of Calgary-based FracKnowledge (that keeps a database of fracing and refracking information derived from more than 150,000 wells), refracking is a large, complicated topic that needs more research and development to make it easy and highly successful. “We have the most up-to-date, largest and fastest growing fracing and completions database in Canada and the U.S. – designed by our senior frac and computer specialists, each with at least one to three decades of experience building and using frac databases,” Leshchyshyn says.
The challenge to an E&P producer, who has just bought acreage in the Bakken, is to identify which operators have performed the most refracks and which reservoirs had the best results. Perhaps the new entrant is only interested in horizontal wells which have been refracked in the last 18 months. The engineers want to compare recompletions to generate a scatterplot. Perhaps they find there’s a strong connection between the use of higher proppant and fluid and higher initial production (IP). They will want to quantify the performance of refracks by comparing the IP rates to the post-refrack rates. Maybe they discover the refrack with the highest IP ratio was refracktured within 16 months of initial completion, while the well with the worst IP ratio was not refracktured until much later.
Think of the potential cost savings the new producer has. The engineers have narrowed in on the key metrics that may help the company achieve maximum production by having insight into the volumes of proppant and fluid to use, the timing of a series of refracks, and the reservoir quality.
This company’s shareholders should be elated with its ROI (return on investment) because the engineers persistently drove down actual costs and optimized unit costs ($/Boe) by finding the right balance between low-cost refracking and enhanced performance. Many refracks have seen oil recovery climb 60 per cent or more.
A study by Bloomberg Intelligence of about 80 wells drilled in North Dakota’s Bakken formation (most were drilled in 2008-2009) and refracked years later “showed a clear pickup in output,” the report noted. “The wells on average produced more than 30 per cent more oil in the month after the refrack than they did in the original completion.”
Refracking has also been effective against the characteristically steep decline in shale wells. Most horizontals produce at a fraction of their IP, yet large volumes of crude oil and natural gas remain locked in the rock.
#Refracking #Brakken #CanadianShale #ShaleIndustry #CrudeOil #Gas #OilandGas #FracKnowledge #Saskatchewan#TheRoughneck #Roughneck #Canada
