Abstract: An isolation assembly for use with coiled tubing is described. The isolation assembly has a check valve for providing selective fluid communication through from the coiled tubing, through the isolation assembly, and into a downhole tool, such a straddle packer. The isolation assembly includes a shuttle moveable within a housing, and plurality of ports to selectively provide fluid communication from within the isolation assembly below the check valve, through the ports, and into the annulus, thus allowing selective surface-controlled equalization of downhole equipment. Also described is a bottom hole assembly including the isolation assembly. An improved method of fracing a formation includes providing a check valve, thus improving the life of the coiled tubing and the safety of the operation, and reducing the time to perform a given downhole operation.

Abstract: An isolation assembly for use with coiled tubing is described. The isolation assembly has a check valve for providing selective fluid communication through from the coiled tubing, through the isolation assembly, and into a downhole tool, such a straddle packer. The isolation assembly includes a shuttle moveable within a housing, and plurality of ports to selectively provide fluid communication from within the isolation assembly below the check valve, through the ports, and into the annulus, thus allowing selective surface-controlled equalization of downhole equipment. Also described is a bottom hole assembly including the isolation assembly. An improved method of fracing a formation includes providing a check valve, thus improving the life of the coiled tubing and the safety of the operation, and reducing the time to perform a given downhole operation.

Abstract: A method of fracturing a formation with a fracturing fluid wherein the formation has particulate material that swells or migrates upon exposure to the fracturing fluid comprises preparing a fracturing fluid comprising (1) a thickening compound comprising a first surfactant selected from the group consisting of a cationic surfactant having only a single cationic group, an amphoteric surfactant and a mixture thereof; and, an anionic surfactant; and, (2) water, wherein no or essentially no inorganic salt is added to the fracturing fluid; and using the fracturing fluid to fracture the formation. A method for recycling a fracturing fluid is also provided.

Abstract: A method of fracturing a formation with a fracturing fluid wherein the formation has particulate material that swells or migrates upon exposure to the fracturing fluid comprises preparing a fracturing fluid comprising (1) a thickening compound comprising a first surfactant selected from the group consisting of a cationic surfactant having only a single cationic group, an amphoteric surfactant and a mixture thereof; and, an anionic surfactant; and, (2) water, wherein no or essentially no inorganic salt is added to the fracturing fluid; and using the fracturing fluid to fracture the formation. A method for recycling a fracturing fluid is also provided.