Conserving Energy Used in Hydraulic Fracturing
Hydraulic fracturing, (or “fracing”, or “fracking”), typically uses large water volumes injected under high pressure into a wellbore. The injected water creates fractures in the geological formation, providing a greater flow rate of oil or natural gas from the formation to the wellbore. Various chemicals and materials are mixed with the water prior to injection, and the entire mixture is usually heated to 40–120 °F with the target temperature dependent on the geologic formation and the chemicals used. Further, heating the water prior to chemical mixing can allow a reduced amount of chemicals to be used in the fracing fluid, and the lower density of the heated water reduces pressure on piping and therefore reduces risk of mechanical failure in the fracing operation. See our earlier Inkling posts on fracing, here and here.Obviously, the initial heating and continued heating of large volumes of frac water requires large amounts of energy. Patent US 8,171,993, “Water heating apparatus for continuous heated water flow and method for use in hydraulic fracturing” provides a more efficient, continuous heating mechanism for frac water. The patent was granted to Ransom Mark Hefley (Elk City, OK), and assigned to Heat On-The-Fly, LLC (Covington, LA), on May 8, 2012. The USPTO considers it to be a well technology that places preheated fluid into a formation. The invention, due to the energy savings incurred in the water heating process, crosses into the patentECO Energy Index.
Hefley’s invention provides a transportable heating apparatus and vessels for mixing input water with heated water and subsequently proppant (the material mixed with water that holds the formation fractures open; sand is commonly used) and chemicals. It allows continuous heating and mixing of large volumes of water, obviating the need for heated storage tanks onsite. A typical fracing operation can require 20–700 storage tanks costing $500–2000 per tank. Thus, not only is energy conserved by a more efficient water heating process, the need to store large volumes of heated fluid is eliminated and the operator can realize significant monetary savings ($10,000-$1.4 million) in equipment. Yet another advantage is a much smaller fracing site footprint.
All in all, a substantial set of benefits.
Modern-Day Alchemy
Alchemy. noun. The medieval forerunner of chemistry, based on the supposed transformation of matter. It was concerned particularly with attempts to convert base metals into gold or to find a universal elixir.Petroleum, oil, and coal are sometimes known colloquially as “black gold.” (For those of you who watched The Beverly Hillbillies sitcom in the 1960s, you might remember Flatt & Scruggs’ The Ballad of Jed Clampett theme “… And up through the ground come a bubbling crude (Oil that is, black gold, Texas tea”).)
Is there such as thing as “reverse alchemy,” in which gold is converted to other substances?
Yes, and it is embodied in the May 15, 2012 patent US 8,176,978, “Method for optimizing in-situ bioconversion of carbon-bearing formations,” granted to Robert A. Downey of Centennial, CO. Downey assigned his invention to Ciris Energy, Inc., also of Centennial. The USPTO places this invention with other wells patents that use microorganism processes. It nicely illustrates an aspect of the patentECO Energy Index.
Downey’s first claim summarizes his invention:
A process for bioconverting a carbon-bearing subterranean formation, and thereby producing a product comprising at least one hydrocarbon, said process for bioconverting comprising:
injecting fluid into a carbon-bearing deposit, located in said subterranean formation, by way of at least one injection well, removing injected fluid and product from said carbon-bearing deposit through at least one production well, said bioconverting being effected by a microbial consortia capable of bioconverting said carbon-bearing deposit so as to produce at least one hydrocarbon, and controlling fluid pressure within at least a portion of said carbon-bearing deposit by use of said injected fluid, said fluid pressure being controlled such that the fluid pressure within at least a portion of said carbon-bearing deposit exceeds the fluid pressure that normally exists in that portion, but does not exceed the tensile strength of said carbon-bearing deposit, thereby avoiding the inducing and/or propagating of fractures in said carbon-bearing deposit.Reading the patent specification, it is clear that the preferred embodiment is the bioconversion of shale [oil] or coal to methane gas.
Black gold to combustible gas = alchemy = chemistry = appropriate use of the nation’s abundant fossil fuel resources.
Learn more about Way Better Patents' patentECO and the patentECO Discovery and Analysis Report on the USPTO Green Technology Pilot Program which granted accelerated examination to green technology patents.
