US shale operators are constantly in search of a better way to stimulate their tight-rock reservoirs.
Sometimes that means focusing on the subsurface to improve production.
Other times it means innovating on the surface to improve operational productivity, i.e., drive down per-well capex.
An example of the latter involves a multiwell stimulation in the DJ Basin of Colorado that is being touted for completing 72 fracturing stages in 75.4 hours of continuous pumping. The job took place back in January on a five-well pad operated by Denver-based PDC Energy, known as the second-largest oil and gas producer in the DJ Basin, behind only Occidental Petroleum.
Supplying the pressure-pumping units to PDC was fellow Denver-based firm Liberty Energy, formerly known as Liberty Oilfield Services. Also involved was Intelligent Wellhead Systems (IWS) which developed some of the technology used to control the pumping operations.
The Houston-headquartered IWS said that zero nonproductive time was incurred during the more than 3 days of continuous pumping, according to a new press release about the project. The efficiency of the operation translated to a 14% reduction of the time normally required to complete a five-well pad.
The development reflects how completions technology providers are attempting to modernize what has historically been a manual operation that relied more on a predetermined pumping schedule than it did on the collection or analysis of real-time data. And in the not-too-distant past, a typical multistage completion required a span of 2–3 hours between stages in order to prepare for the next one.
IWS told JPT that the project for PDC did not utilize the recently embraced "simul-frac" method where up to two stages in two different wells are able to be stimulated at the same time. Though considered the most efficient approach, the technique has limitations as it involves using a larger number of pressure-pumping units to supply enough horsepower to run the dual-well operation.
Instead, the 75.4 hours of continuous pumping was achieved using the older but less capital-intensive "zipper frac" method which calls for a stage in one well to be completed with only a short span of time before another stage is pumped inside an adjacent well. This method saw widespread adoption last decade as operators started completing more multiwell pads and realized that pumping dozens of stages in a single well before moving on to another well counted as the least efficient way to develop their acreage.
IWS also shared that the DJ Basin project marked the first time PDC used the technology developer's sensor and software platform that enables the remote control of up to 24 wellhead valves. IWS added that PDC is currently using the automated-valve platform on its fourth well pad.
The remote operation of valves removes completions personnel from the wellsite's most dangerous areas, known as “red zones." It also trims the time it takes to complete wireline swapovers that are often considered bottlenecks during plug-and-perf operations.
For its part, Liberty said the DJ Basin project represented another milestone in its ongoing effort to maximize uptime for its pressure-pumping fleets.
The initiative is called “Operation 1440” in reference to the minutes that make up a day and was launched in early 2021. Later that year, the service company announced the first major milestone of the initiative was reached when it pumped continuously for 24 hours for an operator in the Permian Basin. That project was aided by another technology provider, Downing, which is the developer of its own wellhead and valve-automation system.
In April, executives from Liberty noted that the company has upgraded more than half of its pressure-pumping fleet with automation software that controls rates and pressures. Liberty ended last year with around 30 active pressure-pumping fleets and acquired the software in 2021 upon closing its $488-million purchase of Schlumberger’s North American completions business unit known as OneStim.
Schlumberger was among the first in the pressure-pumping sector to test automated control systems when it did so more than 5 years ago.
