Abstract: An array of plugging devices are pumped sequentially from the surface through a liner that typically becomes horizontal in nature, where each plugging device is anchorable at a specific position along the length of the line. Perforations are generated above the plugging device. The plugging device may be a cup plug and when pump pressure is applied to the cup the cup moves through the liner. When anchored, the cup directs frac fluids through the perforations to treat the well formation. The plug may be of the type where a full bore is maintained through the liner and allows the cup plug to travel back to the surface due to flow from the well thus eliminating any need for milling obstructions from the well bore. The use of multiple plugging devices allows multizone stage fracing.

Abstract: A single trip multizone time progressive well treating method and apparatus that provides a means to progressively stimulate individual zones through a cased or open hole well bore. The operator can use pre-set timing devices to progressively treat each zone up the hole. At each zone the system automatically opens a sliding sleeve and closes a frangible flapper, at a preselected point in time. An adjustable preset timing device is installed in each zone to allow preplanned continual frac operations for all zones. An optional “Stand-Down-Mode” can be integrated into the timing system so that if pumping stops the timers go into a sleep mode until the pumping resumes. The apparatus can consist of three major components: a packer, a timing pressure device, and a sliding sleeve/isolation device. The packer may be removed.