A Bean that Turns Water into Gel
Powder made from the bean of a relatively unknown plant grown in India and Pakistan can quickly turn water into a very thick gel. The beans are typically used to thicken sauces and processed foods such as ice cream and ketchup. Now, drilling companies who need high-viscosity water to extract oil and natural gas from tight rock formations are buying up guar beans as fast as they are grown.
The surge in demand has multiplied prices and lured many new farmers into the guar bean business. Historically, India and Pakistan have produced over 80% of the worldwide supply of guar beans. However, farmers in Texas, Oklahoma and other states are now planting guar beans to take advantage of these high prices.
Why High Viscosity Water is Needed
Enormous quantities of oil and natural gas are trapped in subsurface rock units that are so tight that fluids can not flow through them. To liberate the oil and natural gas drilling companies pump fluids down a well under pressures that are high enough to fracture the subsurface rock units. This process is known as hydraulic fracturing.
Adding guar bean powder, also known as guar gum, to this water increases its viscosity and makes high-pressure pumping and the fracturing process more efficient.
High viscosity water is needed for a second reason. Sand grains or other tiny granules are mixed with the water that is used for the fracturing process. When fracturing occurs these granules, known as “proppants“, are carried deep into the rock unit by the sudden rush of water that accompanies the opening of fractures.
When the pumps are turned off water pressure within the fractures drops and the fractures close suddenly. If enough proppants have been carried into the fractures they prevent the fractures from closing completely. These partially-closed fractures then become passageways that allow oil and natural gas to flow out of the rock and into the well.
High viscosity water is much more effective at suspending sand grains and carrying them into the fractures.
What are Guar Beans?
Guar beans, also known as cluster beans (Cyamopsis tetragonoloba)have been cultivated in northwestern India and Pakistan for at least several centuries. Guar is an annual legume that grows well in a variety of soil types and in arid to semiarid climates.