Engineered proppants for hydrofracturingPublished on December 15th, 2011 | By: Eileen De Guire
While alternative and renewable energy technologies have been the center of attention as the country works to research and innovate its way to energy independence, the oil and gas industry has been busy, too. In particular, huge reservoirs of natural gas have been found in shale, and it can be extracted by a drilling practice known as horizontal drilling or hydrofracturing, which is often shortened to fracking.
Fracking involves drilling down several thousand feet to the shale level and then the drilling turns horizontal. In the horizontal run, fluids are pumped into the well to create fractures. Granular material is pumped in to prop open the fissures and create an open pathway for the natural gas to escape. (Think of the open spaces between ping pong balls.) The granular material is known in the industry as proppant—that which props open the fracture.
The most common proppant is sand, but lately there has been growing interest in engineered proppants. Engineered proppants are made of ceramic, usually derived from bauxite, and offer the advantages of uniform size and shape, as well as higher strength. The ability to narrowly control particle size maximizes porosity, and therefore the volume of natural gas extracted.
(CARBO Ceramics is an example of a company that has adopted ceramic proppant technology and, according to their financial reports, the business is doing very well. Their website has a number of informative animations and videos about fracking.)
Bauxite is also the primary raw material for alumina and aluminum production. According to the USGS (pdf), almost all bauxite is imported, so there are price pressures from several sources. And, it hardly makes sense to abandon a useful commodity mineral in shale fractures.
Penn State professor, John Hellmann is working on developing glass ceramic proppants from non-bauxite raw materials or even industrial wastes. The mining industry, for example, generates basalt-based tailings that he is investigating for proppants. Ironically, drill cuttings from shale gas wells also show promise as raw materials for engineered proppants.
Hellmann has been invited to present an update on his work at the Ceramic Leadership Summit that will be held in conjunction with the 4th International Congress on Ceramics (ICC4) in Chicago next July. The title and abstract of the talk are below. Also, in a 2 minute video on You Tube, he talks about his career, fracking and proppants work (beginning at about the 55 second mark). It includes an instructive animation on how fracking works.
“Development and Commercialization of High Performance Ceramics for Oil and Natural Gas Recovery”
John Hellmann, Pennsylvania State University
Developments in horizontal drilling technology offer unprecedented access to domestic oil and natural gas deposits, thereby placing the United States on the verge of sustained energy independence. Critical to this technology are spherical ceramic aggregates, known as proppants, which are used for enhancing oil and gas recovery from hydrofractured wells. However, ceramic proppants are derived from sintered aluminosilicates such as bauxite, which is becoming increasingly scarce in the quality and quantities necessary to meet market demand for proppants.
This presentation summarizes our development and commercialization of glass ceramic proppants from alternative raw materials derived from industrial waste streams. These proppants, manufactured from basalt-based mine tailings and drill cuttings from shale gas wells, rival sintered bauxite-based proppants with regard to strength, hardness, specific gravity and conductivity in industry standard testing. Progression from laboratory demonstration to large scale processing and commercialization of these proppants is discussed.