INSTALLATION METHOD OF AN EXTENSIBLE COLUMN WITH THREADED JOINTS Russian patent published in 2020 - IPC E21B29/10 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil and gas industry, namely to methods of construction of wells at drilling intervals with zones of complication. Method includes lowering an expandable string with a mandrel and flaring machine into a well on a drilling tool, orientation of the expandable string to the installation interval, creation of hydraulic pressure in the extensible column until its fixation in the well, disconnection of the tool from the extensible column. For final expansion of the string with threaded joints, expander is used, imparting rotary-forward motion to the tool, and mandrel, imparting forward motion to the tool. Expander is made non-immobile, and below flaring device at distance exceeding length of threaded connection by 2-3 times, mandrel is installed with diameter varying due to pressure drop in drilling tool. To expand column with threaded joints mandrel is lowered to stop of flaring device in transition section, pressure is created in mandrel of such value so that force at expansion of threaded connections of expandable column does not exceed force for lifting by lifting unit. Expansion of threaded connections is performed in several passes till free passage of flare-through device. Further, the extensible column with threaded connections of the flaring device is calibrated. After that, expander is lowered until it stops in transition section of the next threaded joint and its expansion is performed in a similar way.

EFFECT: improving isolation efficiency of the complication zone due to application of a mandrel with diameter varying due to pressure drop for installation of an extensible string with threaded connections in the well due to preservation of their tightness after expansion, exclusion of the valve and simplification of technology with exclusion of application of weighted drilling pipes, hydraulic jack and anchor.

1 cl, 2 dwg