Forward Osmosis: The Green Machine

The Green Machine uses alternative energy and forward osmosis filtration to recycle drilling waste into a high quality completion fluid for use in frac jobs. On each well, over 80% of the drilling waste can be recycled to provide approximately 20% of the water required for hydraulic fracturing.

Standard commercial scale units are trailer mounted systems capable of recycling up to 4 barrels per minute; 168 gallons per minute - 242,000 gallons per day. Units can be custom designed based on size, scale and volume.

Using The Green Machine to recycle drilling waste into completion fluid not only reduces a significant portion of the need for additional fresh water, but
also greatly reduces the amount of heavy truck traffic required to move the waste and source water in and out of the well-site, respectively.

Based on our data and existing industry-related cost structure, the Green Machine, in most cases,
should show the operator a net cost savings when comparing the traditional cost of waste fluid disposal & transportation and subsequent completion fluid cost & transportation. The costs of disposal are virtually eliminated and a significant amount of trucking cost associated with sourcing frac water is also eliminated. 

The Value it Adds

  • Reduces fresh water acquisition cost
  • Reduces wastewater disposal cost
  • Reduces trucking costs (wastewater and fresh water)
  • Reduces completion fluid costs (clay stabilizers, biocides, etc)
  • Reduces drawdown of fresh water supplies
  • Reduces transportation impact (traffic, road damage, etc)
  • Reduces potential environmental impact
  • Significantly reduces carbon footprint

The Green Machine is only one item on the Emerald Surf Sciences tool belt of solutions.

Emerald Surf Sciences' model includes consultation analyses to help operators determine how to
minimize their fluid-related expenses and maximize their cost savings based on their specific operational structure, regulatory factors, geographical limitations, and preferences.

What is Forward Osmosis?

FO is a membrane-based system (similar to RO), but FO differs from RO in that FO uses chemical energy to ‘draw' the water through the membrane instead of using mechanical energy (pressure) to push the water through the membrane. The solution used to draw the water (i.e. power the reclamation process) is typically a highly concentrated, homogenous brine or sugar solution, and the resulting produced water is therefore a diluted version of the draw solution. The undesirable solids and solutes do not pass through the FO membrane, which produces a concentrated waste stream on the source water side of the membrane (Forward osmosis: Principles, applications, and recent developments Tzahi Y. Cath,Amy E. Childress, Menachem Elimelech 2006). One major and important difference between FO and RO is that the water produced by FO is not ‘fresh' water. FO produced water is a diluted draw solution that must have a downstream application in order to be immediately utilized. In the FO reclamation model, the water from a low-salt waste stream (reserve pit and flow-back waste water) is reclaimed by osmosis using a high concentration of clean salt water (NaCl or KCl) to draw water through a selective membrane.

Since most unconventional gas wells in East Texas and North Louisiana utilize fresh Sodium Chloride or Potassium Chloride water (2% to 7% final concentration) as a clay stabilizer during all completion stages, the diluted draw solution (reclaimed water) can be utilized directly as completion fluid on the subsequent stages of the well. By varying the concentration and/or retention time of the draw solution, a clean saltwater stream of known concentration can be produced. The waste stream will be more concentrated (due to less volume), but still meet criterion for E&P waste disposal.

Since FO does not create pressure on the membrane, the frequency of membrane fouling (clogging or contamination with incompatible chemicals) is greatly reduced (Forward osmosis: Principles, applications, and recent developments Tzahi Y. Cath,Amy E. Childress, Menachem Elimelech 2006). Pit water typically contains large amounts of suspended solids from the drilling mud and cuttings. The suspended solids pose a major problem for both RO and evaporative systems; whereas the membrane design and atmospheric operating pressure of the FO system has been shown to function even in extremely turbid water.

How It's Different

How is The Green Machine different from other technologies?

  • Highest water quality: rejects 100% of virus, bacteria, solids, >90% of undesirable solutes including iron, calcium, metals, barium, etc
  • Primary reclamation process is driven by alternative energy; osmotic gradient-drive
  • Portable, scalable, modular; easy set up and can be ‘right-sized'
  • Conducive to combinations of filter media; course, affinity,phase, chemo
  • Safe: entire unit runs on less than 10 psi, has no moving parts other than the self-contained pumps, and uses little electricity
  • Selective filtration: forward osmosis membrane technology rejects unwanted solutes and solids from the waste stream without complicated pre-treatments or fouling
  • Economically competitive with conventional disposal options