The extraction of natural gas from various shale formations has grown rapidly due to recent technology advances in horizontal drilling and hydraulic fracturing. Hydraulic fracturing overcomes the impermeability of shale relative to the release of natural gas trapped in the rock formation. Horizontal drilling allows greater gas collection from each well out of the relatively shallow but expansively wide shale formations. While these technologies have allowed extraction of natural gas from shale formations such as the Marcellus Shale formation in the eastern United States to be economically feasible, implementing these technologies is expensive.
Shale formations, such as the Marcellus Shale formation, may have a very tight structure that does not allow trapped natural gas to migrate through the formation easily. To facilitate gas movement, the shale formation must be fractured and fissures induced in the rock. To accomplish this, fluids, particularly water with a solid such as sand, are pumped at high pressure to crack the rock formation and wedge it open. The fluid used for hydraulic fracturing is known as “frac fluid.” Additives may be used with the frac fluids. These so-called “frac fluid additives” may comprise a myriad of additive compounds of specific type and quantity necessary to meet, among others, the requirements of the shale formation, well depth and well characteristics. Frac fluid additives may comprise, and/or exclude, one or more of scale inhibitors, corrosion inhibitors, biocides, viscosity modifiers, lubricants, surfactants, oxygen scavengers, proppants, and other additive compounds appreciated by one skilled in the art. One notable type of frac fluid additive is a proppant additive, which is a solid, such as sand, that wedges the induced fissures open. Depending upon the geology of the area around the well, many of the frac fluid additives get diluted and washed away by the natural intrusion of underground water that can not be avoided. This water intrusion necessitates the continual addition of additional frac fluid additives that is costly and, in some cases, may be highly impractical.
USPTO Backgrounds
USPTO Backgrounds