Hydraulic activation of mechanically operated bottom hole assembly tool

A method of hydraulically activating a mechanically operated wellbore tool in a bottom hole assembly, the method comprising:

• lowering the bottom hole assembly into a wellbore;
• holding moveable elements of the wellbore tool in an unactivated position using at least one shear pin;
• inserting one or more drop balls into a drilling fluid;
• flowing the drilling fluid and the drop balls to a flow orifice comprising, flowing the drilling fluid and the drop balls to one or more drill bit nozzle inlets located in or below the wellbore tool;
• at least partially plugging a flow orifice with the drop balls to restrict fluid flow and correspondingly increase hydraulic pressure of the drilling fluid;
• creating a force on the at least one shear pin responsive to the hydraulic pressure;
• and
• increasing the hydraulic pressure of the drilling fluid to shear the at least one shear pin, thereby allowing the moveable elements of the tool to move to an activated position.

A method of hydraulically activating a mechanically operated wellbore tool in a bottom hole assembly, the method comprising:

• lowering the bottom hole assembly into a wellbore;
• holding moveable elements of the wellbore tool in an unactivated position using at least one shear pin;
• inserting one or more drop balls into a drilling fluid;
• flowing the drilling fluid including the drop balls to a flow orifice, said flow orifice comprising an activation bushing located in or below the wellbore tool;
• at least partially plugging the flow orifice with the drop balls to restrict fluid flow and correspondingly increase hydraulic pressure of the drilling fluid;
• creating a force on the at least one shear pin responsive to the hydraulic pressure;
• and
• increasing the hydraulic pressure of the drilling fluid to shear the at least one shear pin, thereby allowing the moveable elements of the tool to move to an activated position.

A hydraulically activated mechanical wellbore tool, positionable above a drill bit in a bottom hole assembly disposable in a wellbore, said wellbore tool comprising:

• at least one shear pin holding moveable elements of the well bore tool in an unactivated position;
• and
• a flow restrictor located upstream of the drill bit in the bottom hole assembly, the flow restrictor including at least one opening configured to receive at least one drop ball carried in drilling fluid flowing through the wellbore tool and to facilitate a flow restriction sufficient to increase hydraulic pressure upstream of the flow restriction and create a shearing force on the at least one shear pin,
• wherein the flow restrictor comprises a grate assembly, the grate assembly including:
• a sloped top surface leading to the opening;
• and
• a directional surface configured to guide one or more of the drop balls through the opening and towards one or more drill bit nozzle inlets, the drill bit nozzle inlets sized to become plugged by at least one of the drop balls to provide the flow restriction.