Tech Session Tackles Rock Mechanics, Re-fracs, and Regulations

New learnings on hydraulic fracturing will be highlighted at the SPE Hydraulic Fracturing Conference and Exhibition in The Woodlands, Texas from January 24 to 26.

The North American shale sector has always relied on brute force to get the job done in the subsurface. However, these days hydraulic fracturing involves more science, engineering, and finesse than ever. This is because producers have learned that a deeper understanding of tight rocks is the key to unlocking more of the hydrocarbons trapped within them.

New learnings on this topic will be highlighted at the SPE Hydraulic Fracturing Conference and Exhibition in The Woodlands, Texas from January 24 to 26. The second day of the conference will feature a technical session titled "Fracture Mechanics and Refracturing."

“Some of the papers in this session will be addressing factors that, until recently, we didn’t think were very important at all in the hydraulic fracturing process,” said Dan Hill, department head of the petroleum engineering department at Texas A&M University and one of the session’s chairpersons.

A paper authored by researchers from the University of Texas at Austin (SPE 184871), will offer details of an experimental study on how fracture initiation and propagation are affected by the stiffness or weakness of different rock layers. Another paper, authored by engineers and geomechanical experts from Baker Hughes and GeoNumerical Solutions (SPE 184854), is focused on this same issue and will discuss how to predict the impact of weak rock boundaries using 3D modeling.

Both papers will build on the growing evidence that weak boundaries between different rock layers can halt the propagation of fractures into stiffer rock layers, which results in T-shaped fractures that do little to stimulate the reservoir.

Hill said this problem is known to operators in Eagle Ford Shale of south Texas, where thin layers of soft ash bed are interbedded with the reservoir’s producing intervals.

“When the fractures grow upwards and intersect with these ash beds, they just stop growing and this may be leading the fractures to be much shorter than we thought,” he said, adding that a better of understanding of the issue may lead to improved decision making on which fracturing fluids are needed for an optimal stimulation.

The mixed-session will also feature a paper from Barre & Associates and the Colorado School of Mines (SPE 184837) on the most important considerations involved with refracturing horizontal wells. Jennifer Miskimins is an associate professor of petroleum engineering at the Colorado School of Mines and a co-author of this paper. She said that although the industry slowdown has resulted in less experimental work in this particular area, there remains interest in refracturing due to the great number of opportunities that exist across the US.

“Companies are looking at it as a way to save capital,” she explained. “Instead of having to drill, complete, and stimulate a new well, with refracturing they can take an old well and not worry about two of those components—they just have to go back in and refracture it.”

Adding some diversity to the session will be a paper on hydraulic fracturing regulations (SPE 184859). Authored by layers from the corporate law firm Shook Hardy & Bacon, the paper will address current federal and state rules in addition to the potential policy changes of US President-elect Donald Trump’s administration—making it one of the most up-to-date regulatory reference papers available to industry professionals.

All the above papers will be available for download from OnePetro upon the conclusion of the conference. View this year’s conference agenda, or to register here.

Tech Session Tackles Rock Mechanics, Re-fracs, and Regulations

Trent Jacobs, JPT Senior Technology Writer

29 December 2016