# US 2019/0376364 A1 · Hydrostatic Equalizing Stem Check Valve

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- Number: US 2019/0376364 A1
- Document ID: US20190376364A1
- Status: Published application
- Kind: A1
- Application number: 15/578,017
- Filed: 2017-02-10
- Published: 2019-12-12
- Earliest claimed: 2017-02-10
- Assignees: Halliburton Energy Services, Inc.
- Applicants: Halliburton Energy Services, Inc.
- Inventors: Thomas Murphy; Peter DW Inglis
- Web page: https://patentgrep.com/patent/US20190376364A1

## CPC

- E21B 34/06: in wells
- F16K 15/044: {spring-loaded}
- F16K 15/1823: {for ball check valves}
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)}

## Abstract

A pressure-activated device is inserted in a string for insertion into a borehole. The pressure-activated device has an indexing mechanism. The pressure-activated device has a piloted check valve that prevents the indexing mechanism from operating unless a pressure on an outside diameter of the pressure-activated device exceeds an activation threshold.

## Claims

### Claim 1

An apparatus comprising:
a piston chamber;
a piston moveable within the piston chamber, the piston having a cylinder head and a pilot rod extending from the cylinder head;
a check valve having:
an open position in which fluid flow is permitted from a permanent fluid communication path to an equalizing fluid communication path and is permitted from the equalizing fluid communication path to the permanent fluid communication path, and
a closed position in which fluid flow through the equalizing fluid communication path is permitted from the permanent fluid communication path to the equalizing fluid communication path and is not permitted from the equalizing fluid communication path to the permanent fluid communication path;
a valve spring urging the check valve into the closed position;
a piston spring urging the pilot rod of the piston into engagement with the check valve to urge the check valve into the open position;
a gland surrounding pilot rod;
an equalizing chamber between the cylinder head of the piston and the gland; and
a hydrostatic fluid communication path between the equalizing chamber and a source of hydrostatic pressure.

### Claim 2 (depends on 1)

The apparatus of claim 1 wherein the check valve comprises:
a check valve chamber extending longitudinally in the direction of movement of the pilot rod and having an upstream side and a downstream side;
a ball moveable within the check valve chamber, engageable on an upstream side by the pilot rod, and engageable on the downstream side by the valve spring; and
a seat against which the ball seals.

### Claim 3 (depends on 1)

The apparatus of claim 1 further comprising:
an entry chamber between the gland and the check valve, the entry chamber being in fluid communication with the equalizing fluid communication path; and
an exit chamber on the opposite side of the check valve from the entry chamber, the exit chamber being in fluid communication with the permanent fluid communication path.

### Claim 4 (depends on 1)

The apparatus of claim 1 further comprising a locking mechanism to lock the check valve into the closed position.

### Claim 5 (depends on 4)

The apparatus of claim 4 wherein the locking mechanism is coupled to the cylinder head of the piston.

### Claim 6 (depends on 1)

The apparatus of claim 1 further comprising a locking mechanism selected from the group consisting of a snap ring coupled to the cylinder head of the piston and a collet coupled to the cylinder head of the piston.

### Claim 7

An apparatus comprising:
a tubular housing having an inside diameter and an outside diameter;
a low pressure chamber in the tubular housing between the inside diameter and the outside diameter;
a permanent fluid communication path fluidly coupled to the low pressure chamber;
a high pressure chamber in the tubular housing between the inside diameter and the outside diameter;
a bleed valve between the high pressure chamber and the low pressure chamber;
an equalizing fluid communication path between the low pressure chamber and the high pressure chamber;
an indexing mechanism capable of indexing in the presence of a difference between a pressure in the low pressure chamber and a pressure in the high pressure chamber; and
a piloted check valve fluidly coupled to the outside diameter of the tubular housing and operable to close when a fluid pressure at the outside diameter of the tubular housing exceeds an activation pressure, the piloted check valve located to interrupt the equalizing fluid communication path upon closing.

### Claim 8 (depends on 7)

The apparatus of claim 7 wherein the piloted check valve comprises:
a piston chamber;
a piston moveable within the piston chamber, the piston having a cylinder head and a pilot rod extending from the cylinder head;
a check valve having:
an open position in which fluid flow through the equalizing fluid communication path is permitted from the low pressure chamber to the high pressure chamber and is permitted from the high pressure chamber to the low pressure chamber, and
a closed position in which fluid flow through the equalizing fluid communication path is permitted from the low pressure chamber to the high pressure chamber and is not permitted from the high pressure chamber to the low pressure chamber;
a valve spring urging the check valve into the closed position;
a piston spring urging the pilot rod of the piston into engagement with the check valve to urge the check valve into the open position;
a gland surrounding the pilot rod;
an equalizing chamber between the cylinder head of the piston and the gland; and
a hydrostatic fluid communication path between the equalizing chamber and the outside diameter of the tubular housing.

### Claim 9 (depends on 8)

The apparatus of claim 8 wherein the piloted check valve comprises:
a check valve chamber extending longitudinally in the direction of movement of the pilot rod and having an upstream side and a downstream side;
a ball moveable within the check valve chamber, engageable on an upstream side by the pilot rod, and engageable on the downstream side by the valve spring; and
a seat against which the ball seals.

### Claim 10 (depends on 8)

The apparatus of claim 8 further comprising:
an entry chamber between the gland and the check valve, the entry chamber being in fluid communication with the low pressure chamber; and
an exit chamber on the opposite side of the check valve from the entry chamber, the exit chamber being in fluid communication with the high pressure chamber.

### Claim 11 (depends on 8)

The apparatus of claim 8 further comprising a locking mechanism to lock the check valve into the closed position.

### Claim 12 (depends on 11)

The apparatus of claim 11 wherein the locking mechanism is coupled to the cylinder head of the piston.

### Claim 13 (depends on 8)

The apparatus of claim 8 further comprising a locking mechanism selected from the group consisting of a snap ring coupled to the cylinder head of the piston and a collet coupled to the cylinder head of the piston.

### Claim 14

A method comprising:
including in a string for insertion into a borehole a pressure-activated device having:
an indexing mechanism, and
a piloted check valve that prevents the indexing mechanism from operating unless a pressure on an outside diameter of the pressure-activated device exceeds an activation threshold.

### Claim 15 (depends on 14)

The method of claim 14 further comprising:
inserting the string into the borehole until the pressure on the outside diameter of the pressure-activated device exceeds the activation threshold.

### Claim 16 (depends on 15)

The method of claim 15 further comprising:
sequentially increasing and decreasing the pressure in the borehole to operate the indexing mechanism to cause the pressure-activated device to perform its function.

### Claim 17 (depends on 15)

The method of claim 15 further comprising:
pressure testing the pressure-activated device before inserting the string into the borehole.