Annular and Tubing Swellable Flow Plug for Downhole Tool Assemblies in the Oil and Gas Industry
Publication Date: 2012-Apr-11
The IP.com Prior Art Database
AbstractAnnular and Tubing Swellable Flow Plug for Downhole Tool Assemblies in the Oil and Gas Industry
Title: Annular and Tubing Swellable Flow Plug for Downhole Tool Assemblies in the Oil and Gas Industry
The purpose of this invention is to provide a way of closing off axial flow in a downhole conduit, without requiring any intervention by mechanical tools inside or near to the conduit, nor any mechanical manipulation of the conduit, nor any hydraulic manipulation such as sustained or pulsed pressure application. Conduits at the bottom of wells in the oil and gas industry are sometimes difficult to access mechanically, and pressure applications may undesirably affect some components of the well construction, so a need to close off a flow passage is problematic in these situations, and being able to close off the flow passage without these aspects is valuable.
An important application of this invention will be to enable the shutoff of axial flow through the end of a conduit when that flow is desired only temporarily, such as during the installation into a well of the conduit and before the shutoff has been activated, but when after the installation and during the producing (or injecting) life of the well any flow through the end of the conduit would be undesirable. A specific application would be the installation of a liner at the bottom of a well, when flow through the liner (e.g., for circulation or injection) is desired during installation, but shutting off the flow passage after installation is desired. Another example is a “coated” sand screen (such as Halliburton’s brand name PetroGuard® Treat screen) when during installation it would be desirable to be able to circulate axially through the temporarily radially sealed screen and out and around the bottom end of the screen assembly, and then to have that circulation point closed off for the production (or injection) of the well.
Other conventional means of closing off such a circulation point require running a mechanical plug or shifting tool inside the screen to close or plug mechanically the circulation point at the end of the assembly, and thus require a mechanical tubing string inside the screen during the installation to convey the mechanical device. The requirement for this tubing obviates a significant benefit for using the coated sand screen, which is that otherwise no internal tubing is required to be able to use the temporarily sealed screen as a flow conduit for circulating to the end of the screen assembly, thus avoiding the rig time otherwise required to assemble and later disassemble the inner tubing string. Also, a simple pressure-to-open, close-without-pressure device at the end of the assembly, which could conceivably be used to allow temporary circulation, presents difficult design problems for the application. The nature of the temporarily sealed screen is that it has a relatively low pressure capability, which although sufficient for simple circulation, would severely restrict the operating window for opening such a valve with pressure and...