Hydraulic fishing jar having tandem piston arrangement

Claim 2

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore: a. Inner and outer telescopically interengaged bodies; b. First diametrically defined pressure area having upper and lower sealed ends; c. First tandem piston means immediate one of said upper and lower sealed ends of said pressure area; d. First seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said first diametrically defined pressure area; e. Second seal means between said first tandem piston means and one of said inner and outer interengagable bodies and defining the other of the upper and lower sealed ends of said first pressure area; f. Second diametrically defined pressure area having upper and lower sealed ends; g. Second tandem piston means immediate one of said upper and lower sealed ends of said second pressure area; h. Third seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said second pressure area; and i. Fourth seal means between said second tandem piston means and one of said inner and outer interengagable bodies and defining the other of the upper and lower sealed ends of said second pressure area; said first and second fluid pressure areas being in fluid communication with one another, said first and second pressure areas defining a lubrication chamber therewithin.

Claim 3

The apparatus of claim 1 further comprising means for preventing relative rotational movement between said inner and outer telescopically interengaged bodies.

Claim 4

The apparatus of claim 1 further comprising means for preventing relative rotation between said inner and outer telescopically interengaged bodies, said means for preventing relative rotation being within at least one of the first and second pressure areas.

Claim 5

The apparatus of claim 1 further comprising hammer means carried on one of said inner and outer telescopically interengaged bodies and anvil means carried on the other of said inner and outer telescopically interengaged bodies.

Claim 6

The apparatus of claim 1 further comprising hammer means carried on one of said inner and outer telescopically interengaged bodies and anvil means carried on the other of said inner and outer telescopically interengaged bodies, said hammer means and said anvil means being within at least one of said first and second pressure areas.

Claim 7

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore: a. Inner and outer telescopically interengaged bodies; b. A plurality of diametrically defined pressure areas, each of said areas having upper and lower sealed ends; c. Tandem piston means immediate one of said upper and lower sealed ends of each of said pressure areas; d. Seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said pressure areas; and e. Seal means between said piston means and one of said inner and outer telescopically interengaged bodies and defining one of the upper and lower sealed ends of said pressure ends. said fluid pressure areas being in fluid communication with one another and defining a chamber for receipt of lubricant therewithin.

Claim 8

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore: a. Inner and outer telescopically interengaged bodies; b. A plurality of diametrically defined pressure areas, each of said areas having upper and lower sealed ends; c. Tandem piston means immediate one of said upper and lower sealed ends of each of said pressure areas; d. Seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said pressure areas; and e. Seal means between said piston means and one of said inner and outer telescopically interengaged bodies and defining one of the upper and lower sealed ends of said pressure ends. said fluid pressure areas being in fluid communication with one another and defining a chamber for receipt of lubricant therewithin.

Claim 9

The apparatus of claim 6 further comprising means for preventing relative rotation between said inner and outer telescopically interengaged bodies.

Claim 10

The apparatus of claim 7 wherein said means preventing relative rotation between said inner and outer telescopically interengaged bodies is within at least one of said fluid pressure areas.

Claim 11

The apparatus of claim 6 further comprising hammer means carried on one of said inner and outer telescopically interengaged bodies and anvil means carried on the other of said inner and outer telescopically interengaged bodies.

Claim 12

The apparatus of claim 9 wherein said hammer and anvil means are within at least one of said fluid pressure areas.

Claim 13

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore: a. Inner and outer telescopically interengaged bodies; b. First diametrically defined pressure area having upper and lower sealed ends; c. First tandem piston means immediate one of said upper and lower sealed ends of said first pressure area; d. First seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said first diametrically defined pressure area; e. Second seal means mounted on said first tandem piston means and defining the other of the upper and lower sealed ends of said first pressure area; f. Second diametrically defined pressure area having upper and lower sealed ends; g. Second tandem piston means mounted on one of said upper and lower sealed ends of said second pressure area; h. Third seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said second pressure area; and i. Fourth seal means mounted on said second tandem piston means and defining the other of the upper and lower sealed ends of said second pressure area; said first and second pressure areas being in fluid commuication with one another, said first and second pressure areas defining a lubrication chamber therewithin.

Claim 14

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore: a. Inner and outer telescopically interengaged bodies; b. First diametrically defined pressure area having upper and lower sealed ends; c. First tandem piston means immediate one of said upper and lower sealed ends of said first pressure area; d. First seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said first diametrically defined pressure area; e. Second seal means mounted on said first tandem piston means and defining the other of the upper and lower sealed ends of said first pressure area; f. Second diametrically defined pressure area having upper and lower sealed ends; g. Second tandem piston means mounted on one of said upper and lower sealed ends of said second pressure area; h. Third seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said second pressure area; and i. Fourth seal means mounted on said second tandem piston means and defining the other of the upper and lower sealed ends of said second pressure area; said first and second pressure areas being in fluid commuication with one another, said first and second pressure areas defining a lubrication chamber therewithin.

Claim 15

The apparatus of claim 11 further comprising means for preventing relative rotation between said inner and outer telescopically interengaged bodies.

Claim 16

The apparatus of claim 12 wherein said means for preventing relative rotation comprises splines carried on at least one of said bodies and carried within splineways in at least one of the other of said bodies.

Claim 17

The apparatus of claim 12 wherein said means for preventing relative rotation are within at least one of said first and second pressure areas.

Claim 18

The apparatus of claim 11 further comprising hammer means carried on one of said inner and outer telescopically interengaged bodies and anvil means carried on the other of said inner and outer interengagable bodies.

Claim 19

The apparatus of claim 15 wherein said hammer and anvil means are carried within at least one of said first and second pressure areas.

Claim 20

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore; a. Inner and outer telescopically interengaged bodies; b. First diametrically defined pressure area having upper and lower sealed ends; c. First tandem piston means immediate one of said upper and lower sealed ends of said first pressure area; d. First seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said first diametrically defined pressure area; e. Second seal means mounted on said first tandem piston means and defining the other of the upper and lower sealed ends of said first pressure area; f. Second diametrically defined pressure area having upper and lower sealed ends; g. Second tandem piston means immediate one of said upper and lower sealed ends of said second pressure area; h. Third seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said second pressure area; i. Fourth seal means mounted on said second tandem piston means and defining the other of the upper and lower sealed ends of said second pressure area; j. Hammer means carried on one of said inner and outer telescopically interengaged bodies and anvil means carried on the other of said inner and outer interengagable bodies; and k. Means for preventing relative rotation between said inner and outer telescopically interengaged bodies; said first and second pressure areas being in fluid communication with one another, said first and second pressure areas defining a lubrication chamber therewithin, said inner and outer bodies being interengaged within at least one of the first and second diametrically defined pressure areas, said hammer means and said anvil means being within at least one of said first and second diametrically defined pressure areas, and said means for preventing relative rotation between said inner and outer telescopically interengaged bodies being within at least one of said first and second diametrically defined fluid pressure areas.

Claim 21

In a hydraulic fishing jar adapted to be run into a well on a fishing string and connected to a fishing tool in the well bore; a. Inner and outer telescopically interengaged bodies; b. First diametrically defined pressure area having upper and lower sealed ends; c. First tandem piston means immediate one of said upper and lower sealed ends of said first pressure area; d. First seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said first diametrically defined pressure area; e. Second seal means mounted on said first tandem piston means and defining the other of the upper and lower sealed ends of said first pressure area; f. Second diametrically defined pressure area having upper and lower sealed ends; g. Second tandem piston means immediate one of said upper and lower sealed ends of said second pressure area; h. Third seal means carried by one of said inner and outer interengagable bodies and engagable by the other of said inner and outer interengagable bodies and defining one of the upper and lower sealed ends of said second pressure area; i. Fourth seal means mounted on said second tandem piston means and defining the other of the upper and lower sealed ends of said second pressure area; j. Hammer means carried on one of said inner and outer telescopically interengaged bodies and anvil means carried on the other of said inner and outer interengagable bodies; and k. Means for preventing relative rotation between said inner and outer telescopically interengaged bodies; said first and second pressure areas being in fluid communication with one another, said first and second pressure areas defining a lubrication chamber therewithin, said inner and outer bodies being interengaged within at least one of the first and second diametrically defined pressure areas, said hammer means and said anvil means being within at least one of said first and second diametrically defined pressure areas, and said means for preventing relative rotation between said inner and outer telescopically interengaged bodies being within at least one of said first and second diametrically defined fluid pressure areas.