METHOD OF CASING WELL WITH LINER Russian patent published in 2009 - IPC E21B33/14 

FIELD: oil and gas production.

SUBSTANCE: method of casing well with liner consists in following: before liner lowering and inside liner there are installed a sealing facility, cementing facility, adaptor on external surface of liner, and packer unit connecting supporting column with drilling tubes by means of disconnector. The liner with the disconnector is lowered on the drilling tubes into a production string. Tube space of the liner is sealed; the liner is suspended in the production string by actuating the adaptor and gradually unloading weight of the liner to walls of the production string. The liner is disconnected from the drilling tubes by means of the disconnector with maintaining hydraulic connection. Cement grout is supplied into well and drilling column is lifted out the well. The sealing facility is arranged at the bottom of the liner for sealing the tube space. The liner is suspended and disconnected from the drilling tubes. Load of drilling tubes assembly is transferred onto the disconnector when a gate of a collar comes out from grooves in a nipple; the gate slides along an inclined channel and shuts off inlet into the inclined channel and the closed groove with a shutter till the gate on the collar conjugates with open grooves on the nipple. The drilling column is slightly raised; hydraulic connection between the liner and the drilling column is maintained by means of a packing. Pressure in the liner is raised up to specified. The packer unit disconnects circular space between an open borehole of the well and the liner. Cement grout is pumped into the liner and pushed through with a squeezing plug into annular space of the liner till the squeezing plug stops and pressure jumps at the wellhead due to disconnection of tubular and circular spaces with a locking sleeve of the cementing collar. Further the drilling column is slightly raised over the upper tube of the liner; excess of cement grout is flushed off; and space over the top of the liner column is washed. Upon extracting the drilling column, components of the cementing collar and the sealing facility are drilled over; also the control components wedged in the liner are not turned over.

EFFECT: facilitating sealing of lowered column after lowering and washing of well, control over all components of process accessories, combination of several components of process accessories with different functions at one column, their stage-by-stage actuating.

7 dwg