Valve assembly

A method for deploying a tubing string in a wellbore containing a fluid, comprising:

• coupling the tubing string to a valve assembly, the valve assembly comprising:
• a housing defining a housing flow path for communicating with the tubing string;
• a barrier member located in the housing;
• and
• a bypass arrangement;
• configuring the barrier member in a normally-closed position in which the barrier member restricts access through the housing flow path;
• configuring the bypass arrangement in an open state in which the bypass arrangement defines a bypass flow path that communicates with the housing flow path on opposite sides of the barrier member, wherein the bypass arrangement comprises a variable flow restrictor defined by a flow restrictor ring slidably mounted between a first position in which the flow restrictor ring co-operates with a first feature of the valve assembly to define a first restriction, and a second position in which the flow restrictor ring co-operates with a second feature of the valve assembly to define a second, greater restriction;
• moving the tubing string including the valve assembly downwardly within the wellbore causing fluid from the wellbore to bypass the barrier member via the bypass flow path to thereby fill the tubing string;
• configuring the bypass arrangement in a closed state in which fluid is prevented from bypassing the barrier member;
• and
• pressurizing fluid contained within the tubing string.

A valve assembly for selectively permitting filling and pressurization of a tubing string during deployment into a wellbore, comprising:

• a housing defining a housing flow path;
• a barrier member configurable between open and normally-closed positions to selectively restrict access through the housing flow path;
• and
• a bypass arrangement configurable between open and closed states to selectively permit fluid to bypass the valve member, the bypass arrangement comprising a variable flow restrictor defined by a flow restrictor ring slidably mounted between a first position in which the flow restrictor ring co-operates with a first feature of the valve assembly to define a first restriction, and a second position in which the flow restrictor ring co-operates with a second feature of the valve assembly to define a second, greater restriction,
• wherein the valve assembly is configurable between:
• a first configuration in which the barrier member is in the normally-closed position and the bypass arrangement is in the open state to permit fluid to enter the tubing string via the bypass arrangement;
• a second configuration in which the barrier member is in the normally-closed position and the bypass arrangement is in the closed state to prevent fluid communication and allow pressurization of fluid within the tubing string;
• and
• a third configuration in which the barrier member is open to permit access through the housing flow path of the valve assembly.