The holy grail of optimizing well completions is the ability to design in real time a hydraulic fracturing operation. Slowly fading are the days of “pump and pray,” replaced in part by the technological leaps made in the collection and analysis of millions of datapoints. With these datapoints, it is now possible to recreate the subsurface to better visualize the movement of fluid, the length of fractures and more.
With the commercialization of sealed wellbore pressure monitoring (SWPM), completions engineers can monitor fracture growth and the fluid volumes between treated wells by tracking the pressure response in a nonperforated wellbore. As fractures approach the sealed wellbore, a pressure response is generated. Engineers are able to use the response to determine fluid volumes quickly using pressure gauges mounted at the surface.
One way to visualize it is to think of a balloon animal.
“Take the balloon and curl it 90 degrees, so it looks like a horizontal wellbore,” explained Kyle Haustveit, a senior completions engineer with Devon Energy. “When you squeeze the base of that balloon, you see the upper half expand. So if you had a pressure gauge at the end of that balloon, you’d see a pressure increase. The squeezing is the same force that a fracture from an offset wellbore applies to the sealed wellbore when it intersects the wellbore. That pressure response we see, when squeezing the balloon, is the same that our transducer sees on the wellhead when we have a fracture intersection from an offset or more than one offset wellbore.”
The sealed wellbore, in a way, is working as an antenna to transmit the pressure response to the surface.
“The small squeeze of probably less than a few centimeters of the casing string creates the pressure signal,” Haustveit said. “We amplify the pressure signal by having the sealed wellbore full of fluid, normally whatever drilling leaves in the hole, some type of freshwater or brine.”
E&P Plus recently talked with Haustveit as well as Trey Lowe, vice president of technology with Devon Energy, and Ryan Guest, director of services with Well Data Labs about the development of the SWPM and its uses at the well site.