LIQUEFIED INDUSTRIAL GAS BASED SOLUTION IN HYDRAULIC FRACTURING

摘要

Hydraulic fracturing is commonly performed by injecting a liquid, gas or two-phase fluid down a well bore at sufficient pressure and flow rate to fracture the subterranean formation. The fluid injected into the rock is typically a slurry of water, proppants, and chemical additives. At the end of the fracturing treatment, the well is commonly flushed with water, and the injected fluid is recovered and treated to some degree. Although the concentrations of chemical additives are very low, the recovered fluid may be harmful due in part to hydrocarbon contamination. The present invention presents a hydraulic fracturing treatment that is substantially free of water. Specifically, the present invention is a cryogenic subterranean fracturing fluid, comprising a liquefied industrial gas and a first additive. The liquefied industrial gas may be liquefied carbon dioxide, liquefied nitrogen, or a blend of the two. The liquefied industrial gas mixture should be substantially free of water. In this context, substantially free of water means less than 10% water by volume, or preferably less than 5% water by volume. The first additive may be a biocide. In addition to the first additive, a proppant may be added to the fracturing fluid. In addition to the biocide and/or proppant, additional additives may be added to the liquefied industrial gas as required. Non-limiting examples of such additives include ozone, a friction reducer, an acid, a gelling agent, a breaker, a scale inhibitor, a clay stabilizer, a corrosion inhibitor, an iron controller, an oxygen scavenger, a surfactant, a cross-linker, a non-emulsifier, a pH adjusting agent, or any combination thereof.