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.
Methods and apparatus are provided for reducing surge pressure while running casing into a wellbore. The apparatus includes a running string for running casing having a diverter tool therein. The diverter tool has one or more bypass ports between its upper and lower end which are normally closed. In operation, the diverter tool is automatically cycled between the open and closed positions of the bypass ports during a casing running operation. A pressure event inside the diverter tool deactivates the cyclic opening and closing function of the bypass port.
