Annulus safety valve

An annulus safety valve for use in a subterranean well, for control of fluid flow in an annulus defined between an outer tubular conduit and an inner tubular conduit concentrically disposed within the well, the conduits extending from a first end of the safety valve to a point in said well, the annulus safety valve comprising:

• a cylindrical central housing securable to the inner tubular conduit;
• a fluid flow passage defined through the central housing, in fluid flow communication with the interior of the inner tubular conduit;
• a second housing circumferentially extending around the exterior of, and carried by, the central housing, the second housing having a plurality of valve passages therein in fluid flow communication at one end thereof with fluid in the annulus between the inner and outer conduits;
• at least one equalizing valve including equalizing valve head and seat members, disposed in at least one valve passage in the second housing, the at least one equalizing head and seat members being in normally closed position and selectively actuable to move relative to one another to permit fluid flow through the at least one equalizing valve;
• at least one control valve including control valve head and seat members, disposed in at least one valve passage in the second housing, the at least one control valve head and seat members being in normally closed position and selectively actuable to move relative to one another to permit fluid flow through the at least one control valve;
• a control member mechanically linked to the at least one equalizing valve and the at least one control valve for sequentially actuating the at least one equalizing valve and at least one control valve;
• and
• an actuator mechanically linked to the control member, for selectively actuating the control member, thereby sequentially actuating the at least one equalizing valve and at least one control valve.

An annulus safety valve for use in a subterranean well, for control of fluid flow in an annulus defined between an outer tubular conduit and an inner tubular conduit concentrically disposed within the well, the conduits extending from a first end of the safety valve to a point in said well, the annulus safety valve comprising:

• a cylindrical central housing securable to the inner tubular conduit;
• a fluid flow passage defined through the central housing in fluid flow communication with the interior of the inner tubular conduit;
• a second housing circumferentially extending around the exterior of, and carried by, the central housing, the second housing having a plurality of valve passages therein in fluid flow communication at one end thereof with fluid in the annulus between the inner and outer conduits;
• at least one equalizing valve including equalizing valve head and seat members, disposed in at least one valve passage in the second housing, the at least one equalizing valve head and seat members being in normally closed position and selectively actuable to move relative to one another to permit fluid flow through the at least one equalizing valve;
• at least one control valve including control valve head and seat members, disposed in at least one valve passage in the second housing, the head and seat members being in normally closed position and selectively actuable to move relative to one another to permit fluid flow through the at least one control valve;
• a control member mechanically linked to the at least one equalizing valve and the at least one control valve for sequentially actuating the at least one equalizing valve and at least one control valve;
• an actuator, mechanically linked to the control member and in fluid flow communication with a control conduit, for selectively actuating the control member and thereby actuating the at least one equalizing valve and at least one control valve in response to an increase in fluid pressure amplitude from the control conduit;
• a control valve biasing member for biasing each of the at least one control valve heads into a normally closed position;
• an equalizing valve biasing member for biasing each of the at least one equalizing valve heads into a normally closed position;
• a control biasing member for biasing the control member into an unactuated position while the at least one control valve and the at least one equalizing valve are in normally closed position.
• wherein the annulus safety valve is operable in a plurality of operating modes including:
• a normally closed mode in which fluid is not permitted to flow from the annulus through the plurality of valve passages in the second housing;
• an equalizing mode in which a first volume of fluid is permitted to flow from the annulus through the valve passages in the second housing having equalizing valve members disposed therein;
• a flowing mode in which a second volume of fluid, of larger magnitude than the first volume, is permitted to flow from the annulus through the valve passages in the second housing having control valve members disposed therein;
• and
• a bypass mode in which fluid is permitted to flow through the plurality of valve passages in the second housing and into the annulus in a flow direction opposite that of the equalizing mode and the flowing mode.

An annulus safety valve for use in a subterranean well, the subterranean well having an outer tubular conduit and an inner tubular conduit concentrically disposed therein, the conduits extending from a first end of the safety valve, the inner tubular conduit extending through a wellbore sealing member, to a point in the subterranean well, the inner tubular conduit, outer tubular conduit, and wellbore sealing member defining an annulus containing a fluid in a pressurized condition that creates a pressure differential across the wellbore sealing member, the annulus safety valve comprising:

• a cylindrical central housing securable to the inner tubular conduit;
• a fluid flow passage defined through the central housing in fluid flow communication with the interior of the inner tubular conduit;
• a second housing circumferentially extending around the exterior of, and carried by, the central housing, the second housing having a plurality of valve passages therein in fluid flow communication at one end thereof with the pressurized fluid in the annulus between the inner and outer conduits;
• at least one equalizing valve, including equalizing valve head and seat members, disposed in at least one valve passage in the second housing, the equalizing valve head and seat members being in normally closed position and selectively actuable to move relative to one another to permit fluid flow through the at least one equalizing valve, thereby equalizing the pressure differential across the wellbore sealing means;
• at least one control valve including control valve head and seat members, disposed in at least one valve passage in the second housing, the control valve head and seat members being in normally closed position and selectively actuable to move relative to one another to permit fluid flow through the at least one control valve;
• a control member, mechanically linked to the at least one equalizing valve and at least one control valve for sequentially actuating the at least one equalizing valve and at least one control valve;
• an actuator, mechanically linked to the control member and in fluid flow communication with a control conduit for selectively actuating the control member and thereby sequentially actuating the at least one equalizing valve and at least one control valve in response to fluid pressure of a preselected amplitude from the control conduit;
• a control valve biasing member for biasing each of the at least one control valve heads into a normally closed position;
• an equalizing valve biasing member for biasing each of the at least one equalizing valve heads into a normally closed position;
• a control biasing member for biasing the control member into an unactuated position while the at least one control valve and the at least one equalizing valve are in normally closed position.
• wherein the annulus safety valve is operable in a plurality of operating modes including:
• a normally closed mode in which fluid is not permitted to flow from the annulus through the plurality of valve passages in the second housing;
• an equalizing mode in which a first volume of fluid is permitted to flow from the annulus through the valve passages in the second housing having equalizing valve members disposed therein in response to control fluid pressure of a first preselected amplitude applied to the actuator from the control conduit, thereby reducing the pressure differential across the wellbore sealing element;
• a flowing mode in which a second volume of fluid, of larger magnitude than the first volume, is permitted to flow from the annulus through the valve passages in the second housing having control valve members disposed therein in response to control fluid pressure of a second preselected amplitude, greater in magnitude than the first preselected amplitude, applied to the actuator from the control conduit;
• and
• a bypass mode in which fluid is permitted to flow through the plurality of valve passages in the second housing and into the annulus in a direction opposite that of the equalizing mode and the flowing mode.

A method of controlling fluid flow in an annulus defined between an outer tubular conduit and an inner tubular conduit, concentrically disposed within a subterranean well, the conduits extending from a first end of an annular safety valve to a point in the well, comprising the steps of:

• assembling at the top of the well, onto the inner tubular conduit, an annulus safety valve, including:
• a housing securable to the inner tubular conduit;
• a fluid flow passage defined through the housing, in fluid flow communication with the of the inner tubular conduit;
• a plurality of valve passages circumferentially spaced about the housing in fluid flow communication at one thereof with fluid in the annulus between the inner and outer conduits;
• at least one equalizing valve including equalizing valve head and seat members, disposed in at least one valve passage, the head and seat members being in normally closed position and selectively actuable to move relative to one another to permit fluid flow through the at least one equalizing valve;
• at least one control valve including control valve head and seat members, disposed in at least one valve passage, the control valve head and seat members being in normally closed position and selectively actuable to move relative to one another to permit fluid flow through the at least one control valve;
• running the annulus safety valve into position within the well;
• actuating the equalizing valve head and seat members from the normally closed position to permit fluid flow therethrough;
• and
• further actuating the control valve head and seat members from the normally closed position to permit fluid flow therethrough.

A subterranean well annulus safety valve for control of fluid flow in an annulus defined between outer and inner tubular conduits disposed within the well, the conduits extending from an end of the annulus safety valve to a point in the well, the annulus safety valve comprising:

• a housing securable to the inner of the tubular conduits;
• a fluid flow passageway defined through the housing and in fluid flow communication with the inner of the tubular conduits;
• a plurality of valve passages circumferentially spaced about the housing and in fluid flow communication at one end thereof with fluid in the annulus between the outer and inner conduits;
• equalizing valve means, including head and seat members, disposed in at least one of the valve passages, the head and seat members in normally closed position to prevent fluid flow from the annulus through the equalizing valve means, the head and seat members movable relative to one another to permit fluid flow through the equalizing valve means;
• and
• at least one control valve means disposed in at least one of the valve passages, the control valve means being in normally closed position to prevent fluid flow from the annulus through the control valve means, the at least one control valve means actuable to permit fluid flow therethrough in a volume greater than that through the equalizing valve means.