01 July, 2014

Unconventional Fracturing

 

Hydraulic fracturing has become so widely used, principally in shale well completions, the casual observer might be inclined to think it’s not only commonplace but a standard, one-size-fits-all technology application. Not so.

Hydraulic fracturing has become so widely used, principally in shale well completions, the casual observer might be inclined to think it’s not only commonplace but a standard, one-size-fits-all technology application.

Not so.

Reservoirs are nothing if not variable, and hydraulic fracturing design and implementation are complex undertakings.

This is particularly true today.

“The current methods allow dozens of fractures to be created in a single wellbore, which is essential to developing these types of reservoirs,” said Steve Hennings, owner and principal engineer at Source Rock Engineering in Littleton, Colo. “But in most cases, treatment costs have escalated beyond the cost to drill the well.

Additionally, actual field results from around the world show that relatively slight changes in treatment design have huge impacts on production rates, he continued.

“Until the appropriate treatment design is identified and confirmed for each individual play,” he said, “commercial development of shale or tight reservoirs is difficult or even impossible to achieve.”

Along with the fracturing experts, there are other industry professionals who must have an understanding of this technology in order to input their own brand of expertise to ensure that all goes well.

Enter the geologist.

“Successful treatment design and optimization for unconventional reservoirs requires that we integrate formation data from a variety of sources,” Hennings said.

This includes key geologic data that often aren’t considered or collected for conventional reservoirs.

“If there are people working to implement development plans and not talking to geologists, it’s a really big red flag,” he emphasized. “It’s so significant to incorporate the geology with well completion design.”

Target Audience

Hennings doesn’t just talk the talk; he walks the walk.

Recognizing the need to bring up-to-speed the professionals who are not widely recognized as essential to these multi-faceted unconventional completions, he travels far and wide presenting a daylong educational course. It covers results gleaned from a variety of hydraulic fracturing field trials worldwide that entail completions in shales and tight reservoirs.

Both technical and non-technical factors controlling the success of a particular treatment design are addressed, as well as a review of the reservoir properties that govern which type of fracturing treatment should be most applicable to a new play area.

A unique aspect of the short course is its target audience.

Hennings said it’s designed for geologists, engineers and people with some technical background on evaluating and developing oil and gas.

“It’s probably not for people who do this kind of work every day,” he noted. “It’s for (those) who want to get more familiar with what’s involved with it and why people request the information they do.”

“For example,” he said, “what kind of information do the people completing these wells need from the geologist, and what are they using that information for?”

Hennings emphasized the course participants will acquire an improved understanding of myriad aspects of hydraulic fracturing:

  • Unique terminology applied in current hydraulic fracturing treatments.
  • Concepts and terms that are unique in defining shale and tight reservoir properties.
  • Five different objectives for creating a hydraulic fracture.
  • Fluid, equipment, proppant and other design options.
  • Data and concepts required to select the appropriate treatment interval.
  • Methods that are being applied in the current major plays – and why they vary by play.
  • Treatment design and calibration field tests.
  • Methods for evaluating a treatment, and common evaluation mistakes.
  • Common mistakes in designing treatments.