Subsurface shutoff valve and control means

Claim 2

A shutoff control system for a producing string extending within a well bore, comprising: a. a shutoff valve interposed in the producing string, the valve including a control chamber which, when subjected to a pressure that exceeds the internal pressure by a preselected differential, causes the shutoff valve to close, so as to stop all flow through the producing string; b. a pressure fluid reservoir carried by the producing string, connected to the shutoff valve control-chamber and having a pressure-fluid capacity capable of pressurizing the shutoff valve control chamber sufficiently to effect closure of the shutoff valve; c. a control line extending from the reservoir to the surface, at or near the wellhead; d. a source of pressure fluid connectable to the control line for supplying pressure fluid to the reservoir; e. a check valve preventing return flow of pressure fluid from the reservoir; f. and a valve means interposed between the reservoir and the shutoff-valve control-chamber for supplying pressure fluid to the shutoff-valve control-chamber in the event of loss of pressure in the control line.

Claim 3

A control system as defined in claim 1, wherein: a. a control means, carried by the tubing string in proximity to the shutoff valve, is interposed in the control line and includes said valve means, the control means also including further valve means connected to the shutoff-valve control-chamber, said further valve means being responsive to pressure in excess of that supplied by the reservoir to bypass the reservoir and effect closure of the shutoff valve.

Claim 4

A control system as defined in claim 2, wherein: a. a vent line extends from the control means to the surface, at or near the wellhead; b. and vent-valve means within the control means is connected to the control line and vent line to minimize back pressure.

Claim 5

A control system as defined in claim 1, wherein: a. the shutoff valve includes a normally tubular sleeve, the control chamber surrounds the sleeve, and the sleeve closes radially inwardly.

Claim 6

A shutoff valve control-system for a producing string extending within a well bore, comprising: a. a shutoff valve interposed in the producing string, the valve including a control chamber which, when subjected to pressure exceeding a predetermined amount, closes the shutoff valve to flow through the producing string; b. a pressure-fluid reservoir carried by the tubing string and having sufficient capacity to close the shutoff valve; c. a control means also carried by the tubing string in proximity to the shutoff valve; d. a control line extending from the reservoir through the control means to the surface, at or near the wellhead; e. a check valve for preventing back flow from the reservoir to the control line; f. means at the surface for supplying fluid to the control means at a maintenance pressure, at a first operating pressure for delivery to the reservoir and at a second higher operating pressure; g. a connecting line between the control means and the shutoff-valve control-chamber; h. a first valve means in the control means operable to connect the reservoir with the shutoff-valve control-chamber upon drop in said maintenance pressure, to effect closure of the shutoff valve; i. and a second valve means in the control means responsive to said second operating pressure to connect the shutoff-valve control-chamber with the control line and also to effect closure of the shutoff valve.

Claim 7

A shutoff valve control-system for a producing string extending within a well bore, comprising: a. a shutoff valve interposed in the producing string, the valve including a control chamber which, when subjected to pressure exceeding a predetermined amount, closes the shutoff valve to flow through the producing string; b. a pressure-fluid reservoir carried by the tubing string and having sufficient capacity to close the shutoff valve; c. a control means also carried by the tubing string in proximity to the shutoff valve; d. a control line extending from the reservoir through the control means to the surface, at or near the wellhead; e. a check valve for preventing back flow from the reservoir to the control line; f. means at the surface for supplying fluid to the control means at a maintenance pressure, at a first operating pressure for delivery to the reservoir and at a second higher operating pressure; g. a connecting line between the control means and the shutoff-valve control-chamber; h. a first valve means in the control means operable to connect the reservoir with the shutoff-valve control-chamber upon drop in said maintenance pressure, to effect closure of the shutoff valve; i. and a second valve means in the control means responsive to said second operating pressure to connect the shutoff-valve control-chamber with the control line and also to effect closure of the shutoff valve.

Claim 8

A control system as defined in claim 5, wherein: a. a vent line extends from the control means to the surface; b. a vent-valve means is connected to the shutoff-valve control-chamber and maintained in an open position when said maintenance pressure is present in the first and second valve means, to prevent build up of back pressure tending to reduce the effect of the maintenance pressure; c. said vent-valve means being adapted to close upon any substantial drop in the maintenance pressure, so as to prevent loss of pressure in the control chamber when the shutoff valve is closed; d. and said vent-valve means is adapted to reopen upon restoration of the maintenance pressure.

Claim 9

A control system as defined in claim 6, wherein: a. said shutoff valve includes a sleeve formed of tubular elastomeric material including a reinforcing means which comprises both circumferential and pre-stressed-longitudinal reinforcing; b. said control chamber is annular and surrounds the shutoff-valve sleeve for effecting radially inward compression of the sleeve; c. the reinforcing means prevents axial extrusion of the sleeve when its central portion is radially compressed inward to effect valve closure and the sleeve is also subjected to a large pressure differential between its ends; d. and the reinforcing means prevents inward rupture of the end portions of the sleeve when its central portion is radially compressed inward to effect valve closure and each of said end portions is subjected to a large differential between the external closing pressure and a smaller internal pressure.

Claim 10

A shutoff valve for a tubing string extending within a well bore, comprising: a. a tubular housing having annular fittings at opposite ends for interposed connection to a tubing string; b. annular means disposed axially inward from each fitting having a peripheral set of radially outwardly projecting rib elements forming axially remote extremities; c. a pre-stressed reinforcing cord extending longitudinally between the sets of rib elements and looped about the rib elements at each end so as to form a peripheral set of pre-stressed reinforcing elements parallel to the axis of the shutoff valve; d. a reinforcing means wrapped about the first reinforcing cord; e. a tubular member formed of elastomeric material impregnating the reinforcing cord and extending radially inwardly and radially outwardly therefrom, and including end portions surrounding the annular means; f. the outer periphery of the tubular member forming with the housing an annular control chamber adapted to receive pressure fluid to effect radially inward pressure on the tubular member so as to compress the mid-portion of the tubular member, causing said mid-portion to form a solid cylinder shutting off flow therethrough; g. the reinforcing cord, reinforcing means and tubular member forming, on compression of the tubular member, diameter-transition zones adjacent to each of its ends, between its solid-cylinder mid-portion and these ends, wherein the reinforcing cord and reinforcing means are essentially conical or bell-shaped and restrain the tubular member against either substantial axial displacement in response to pressure differential between the axial ends thereof or inward rupture, caused by pressure differential between the exterior and the interior of the sleeve in said diameter-transition zones.

Claim 11

A shutoff valve for a tubing string extending within a well bore, comprising: a. a tubular housing having annular fittings at opposite ends for interposed connection to a tubing string; b. annular means disposed axially inward from each fitting having a peripheral set of radially outwardly projecting rib elements forming axially remote extremities; c. a pre-stressed reinforcing cord extending longitudinally between the sets of rib elements and looped about the rib elements at each end so as to form a peripheral set of pre-stressed reinforcing elements parallel to the axis of the shutoff valve; d. a reinforcing means wrapped about the first reinforcing cord; e. a tubular member formed of elastomeric material impregnating the reinforcing cord and extending radially inwardly and radially outwardly therefrom, and including end portions surrounding the annular means; f. the outer periphery of the tubular member forming with the housing an annular control chamber adapted to receive pressure fluid to effect radially inward pressure on the tubular member so as to compress the mid-portion of the tubular member, causing said mid-portion to form a solid cylinder shutting off flow therethrough; g. the reinforcing cord, reinforcing means and tubular member forming, on compression of the tubular member, diameter-transition zones adjacent to each of its ends, between its solid-cylinder mid-portion and these ends, wherein the reinforcing cord and reinforcing means are essentially conical or bell-shaped and restrain the tubular member against either substantial axial displacement in response to pressure differential between the axial ends thereof or inward rupture, caused by pressure differential between the exterior and the interior of the sleeve in said diameter-transition zones.

Claim 12

A shutoff valve as defined in claim 8, wherein: a. the reinforcing means includes a helical wrapped cord externally of the longitudinally extending cord.

Claim 13

A shutoff valve as defined in claim 8, wherein: a. the reinforcing means includes circumferential wrappings of fabric material.

Claim 14

A shutoff valve as defined in claim 8, wherein: a. the ribs of each of the annular means define an annular channel; b. and a multiple wrapping of strands secure the axial end portions of the reinforcing cord in wrapped relation with the radial ribs.

Claim 15

A shutoff valve for a tubing string extending within a well bore, comprising: a. a tubular housing having annular fittings at opposite axial ends for interposed connection to a tubular string; b. tubular elements disposed axially inward from the fittings and fixed against axial displacement; c. a sleeve of elastomeric material extending between and covering the tubular elements, the end portions of the sleeve and tubular elements having mating grooves and channels to secure the sleeve against substantial axial movement; d. the sleeve forming with the surrounding housing an annular pressure chamber adapted to receive pressure fluid for compressing the sleeve radially and cause the central portion of the sleeve to form a solid cylinder shutting off flow through the sleeve; e. and longitudinally and circumferentially extending reinforcing means imbedded in the sleeve to cause the sleeve under high external pressure to form a diameter-transition zone adjacent to each tubular element, wherein the reinforcing means is essentially conical or bell-shaped and causes the sleeve to resist both axial loads caused by pressure differential between its axial ends when the central portion is closed and radially inward collapsing loads in the diameter-transition zones, caused by a differential between the external closing pressure and the internal pressure or pressures.

Claim 16

A shutoff valve for a tubing string extending within a well bore, comprising: a. a tubular housing having annular fittings at opposite axial ends for interposed connection to a tubular string; b. tubular elements disposed axially inward from the fittings and fixed against axial displacement; c. a sleeve of elastomeric material extending between and covering the tubular elements, the end portions of the sleeve and tubular elements having mating grooves and channels to secure the sleeve against substantial axial movement; d. the sleeve forming with the surrounding housing an annular pressure chamber adapted to receive pressure fluid for compressing the sleeve radially and cause the central portion of the sleeve to form a solid cylinder shutting off flow through the sleeve; e. and longitudinally and circumferentially extending reinforcing means imbedded in the sleeve to cause the sleeve under high external pressure to form a diameter-transition zone adjacent to each tubular element, wherein the reinforcing means is essentially conical or bell-shaped and causes the sleeve to resist both axial loads caused by pressure differential between its axial ends when the central portion is closed and radially inward collapsing loads in the diameter-transition zones, caused by a differential between the external closing pressure and the internal pressure or pressures.

Claim 17

A shutoff valve as defined in claim 12, wherein: a. each tubular element includes a set of radiating ribs; b. the longitudinal reinforcing include axial extremities looped about the radiating ribs and held under tension stress between the tubular elements.

Claim 18

A shutoff valve as defined in claim 12, wherein: a. each set of radiating ribs forming a circumferential channel adjacent the axial extremities of the longitudinal reinforcing; b. and a tie strand received in the channel encompasses and restrains the reinforcing.

Claim 19

A shutoff valve as defined in claim 12, wherein: a. each of the tubular elements disposed axially inward from the annular fitting terminates at its inward extremity in a lip that is maximally rounded, so as to minimize bending stresses in the sleeve and its reinforcing where the sleeve in closing bends across the lip.