Pipe handling system

Abstract

This system is used for removing from and/or placing pipe in a well. The system includes a vertically movable power head which is mounted on a tower. A pipe transfer elevator which is connected to a pulley system including at least one cable extending around a sheave located on the movable power head is used to transfer pipe between the pipe storage area and the power head. A pipe string holder is mounted in a hole formed in the tower platform. The pipe string holder is adapted to releasably hold the pipe string. The pipe transfer elevator includes an arcuate member which is adapted to fit over the smaller diameter portion of a pipe but yet contact the pipe coupling which is of a larger outside diameter for moving the pipe between the pipe storage area and the tower. The pipe string holder includes a pair of pivotable members each having a semicircular shoulder formed therein and facing one another to form a substantially circular shoulder.

Description

This invention relates to wells. More particularly, this invention is a new system for use on a tower for removing from and placing pipe in a well, such as an oil and gas well casing.

Generally, a conventional pipe or casing handling system includes a large rotary table on the platform of a rig. The pipe is lifted and lowered with a large split block or hoist and elevator. Very heavy expensive power tongs are used for coupling and disconnecting pipes to form or remove, respectively, a pipe string or casing. The casing or pipe string is held by very heavy power slips located on the tower platform. With such conventional oil and gas well pipe handling systems up to six or more men are required to handle the equipment efficiently.

Experts in the industry are continuously seeking to lighten the heavy equipment required for pipe handling in oil and gas wells while at the same time making certain the equipment is strong enough to handle the operations. Such experts are also continuously trying to improve the operation of pipe handling systems thus requiring fewer men.

This invention is a new system for use on a tower for removing from and placing pipe in a well. Instead of the conventional split block and power tongs for moving the pipe and threading a pipe string together or unthreading the pipe string a top power head is movably mounted on the tower. The power head performs among other things the function of lowering and/or raising the pipe vertically along the tower and also of threading or unthreading the pipe string. A pulley system is connected to the power head and movable vertically with the power head. A pipe transfer line extends around the pulley. A pipe transfer elevator is attached to the free end of the pipe transfer line. The pipe transfer elevator is adapted to engage the coupling of a pipe, lift the pipe, and move the pipe to the top power head for connecting to the power head. The power head is then lowered and the pipe connected to the pipe string holder. As the pipe is being lowered by the power head the pipe transfer elevator is moved toward the pipe storage area for connection to another pipe.

Our new pipe transfer elevator comprises an arcuate member having a radially inwardly extending shoulder. The space between the extremities of the arcuate member is sufficiently large for the arcuate member to fit over a smaller diameter portion of the pipe. However the space is sufficiently large for the arcuate member to hold the pipe coupling and prevent the pipe from falling out during movement between the pipe storage and the power head. The radial shoulder contacts the underside of the pipe coupling for movement and support of the pipe.

Our new pipe string holder comprises a pair of pivotable members with each member being provided with a semicircular shoulder. The semicircular shoulders face one another to provide a substantially circular shoulder for supporting a pipe string.

The invention as well as its many advantages will be further understood by reference to the following detail description and drawings in which:

FIG. 1 is a front elevational view, partly schematic, illustrating our new pipe system;

FIG. 2 is a side elevational view, partly schematic, of the new pipe handling system;

FIG. 3 is a side elevational view with a schematic representation of the lowering of a pipe for connection to the pipe string holder while the pipe transfer elevator is simultaneously moving to the pipe storage area for grasping another piece of pipe;

FIG. 4 is a side elevational view illustrating the upward movement of the top head and the action of the pipe transfer elevator in moving the next pipe to the power head;

FIG. 5 is a perspective view showing our new pipe transfer elevator;

FIG. 6 is a sectional view illustrating our new pipe string holder;

FIG. 7 is a top plan view taken generally along line 7--7 of FIG. 6;

FIG. 8 is a sectional view similar to FIG. 6 showing the pivotable members in the open position to permit the raising or lowering of the pipe string into the well.

Referring to FIG. 1 the new pipe handling system includes a tower indicated generally by the numeral 10. The tower includes power head guides 12 and 14 along which a power head 16 is moved vertically. The means for moving the power head along the guides may be any conventional means such as the chain mechanism shown in U.S. Pat. No. 3,286,777.

A spindle 18 extends vertically downwardly from the lower portion of the power head 16. Spindle 18 is provided with threads 20 for attachment of a pipe coupling.

A pulley system is used for lifting pipe upwardly to the power head 16 for a threaded connection to spindle 18. In the particular preferred emboidment shown the pulley system includes a pair of spaced apart cables 22 and 24 which are detachably anchored to the base of the tower 10. Cables 22 and 24 extend around coaxial sheaves 26 and 28, respectively. The free ends of cables are detachably connected to the transfer elevator 30.

As shown in FIG. 5 the pipe transfer elevator 30 includes a pair of wing members 32 and 34 with eye bolts 36 and 38 inserted in the ends of the wing members 32 and 34 respectively. The eye bolt 36 and 38 can be connected to the hooks 40 and 42 respectively (see FIG. 1) connected to cables 22 and 24 respectively.

The pipe transfer elevator 30 includes an arcuate portion 44 large enough to encompass coupling 52 of the pipe. The extremities 46 and 48 of the arcuate portion 44 are arcuately spaced apart a sufficient distance so the arcuate member 44 may be placed around the smaller diameter portion 50 of the pipe. Though the space between the extremities of the arcuate portion is such that the arcuate portion will fit over the smaller outside portion of the pipe the space is sufficiently small to prevent the pipe from falling out of the pipe transfer elevator 30 while it is being moved between the pipe storage area and the power head. A shoulder 54 extends radially inwardly from the inside of arcuate portion 44 and is adapted to contact the bottom edge of the coupling 52.

Referring again to FIG. 1 a pipe string holder 56 is located in a hole formed in the platform 58. The pipe string holder is adapted to releasably hold the pipe string. In the specific embodiment shown in FIGS. 6 through 8 the platform 58 is provided with a pipe centralizer 60. A pipe string holder adapter 62 is mounted in the centralizer. The pipe string holder adapter includes a central bore 64 of sufficient diameter for the pipe string to be raised or lowered therethrough and also includes a diametric groove 66 (see FIG. 7) of sufficient width to receive the two pivotable members 68 and 70.

Four angle plates 72 are connected to the sides 74 of the pipe string holder adapter by means of connectors 76. The connector and the pipe string holder adapter sides 74 position and prevent undue lateral movement of the pivotable members 68 and 70.

Pivotable pipe string holders 68 and 70 are provided with semicircular shoulders 78 and 80, respectively. The semicircular soulders face one another so that when the pivotable members are in the positions shown in FIGS. 6 and 7 a substantially circular shoulder is formed for supporting the pipe string.

As shown in FIG. 6 the outside longitudinal edge of each pivotable member 68 and 70 includes a portion 82 and 84 respectively which tapers downwardly and inwardly at an angle at approximately 45.degree. to the horizontal when the pivotable members are positioned to hold a pipe string.

The inner longitudinal portions 86 and 88 on the pivotable members 68 and 70 also extend at an angle of approximately 45.degree. with the horizontal. Portions 86 and 88 are spaced from the angle plates 72 by a small amount of say 0.0032 inches when in the position shown in FIG. 6.

Pivotable members 68 and 70 are also beveled at 90 and 92 respectively. Thus when pivotable members 68 and 70 are pivoted outwardly to remove a pipe from a well or insert a pipe into the well the tapered portions 82 and 84 lie flat against the pipe string holder member adapter 62 and the beveled portions 90 and 92 lie flat against the floor of grooves 66. In operations as shown in FIG. 1 the pipe transfer elevator is lifting a pipe up to the spindle 18. The length of each cable 22 and 24 is predetermined and chosen so that when the power head 16 reaches its top position in tower 10 the transfer elevator 30 is in position for the power head to rotate spindle 18 to thread the pipe onto the thread 20 of the spindle. This position is shown in FIG. 2.

The power head with the attached pipe is then lowered for connection to the pipe string. The chain wrench 57 is held against a portion of the tower 10 to prevent rotation of the pipe string while the additional pipe is threaded into the coupling of the top pipe in the pipe string. The chain wrench is then removed and the casing string raised a sufficient enough distance to permit the opening of the pipe string holding parts 68 and 70.

The pipe string is then lowered by lowering the power head 16, as shown in FIG. 3. While the pipe string is being lowered by the power head, the transfer elevator 30 is also moving downwardly at double the speed of the speed of the power head. The transfer elevator can be removed from the pipe string and attached to the next pipe as shown in the broken lines in FIG. 3. This is a great time saving feature because the pipe transfer elevator 30 is already on its way and being attached to the next pipe in the pipe storage area laterally spaced from the tower while the string is being lowered. Also while the string is being lowered the pipe string holding members 68 and 70 are again closed so that the lower portion of the coupling will be supported by the semicircular shoulders 78 and 80.

After the top pipe is fully inserted into the pipe string holding tool the direction of rotation of spindle 18 is reversed to remove the spindle from the top pipe. During the removal of the spindle the chain wrench 57 is again held tightly against the tower to prevent rotation of the pipe string while the spindle is unscrewed from the top pipe.

Thereafter as shown in FIG. 4 the power head 16 is moved upwardly along the tower 10. As the power head moves upwardly the next pipe is grabed by the pipe string elevator 30 and moved into position for attachment to spindle 18 and the cycle repeated.

The series of steps described above for making up a pipe string or casing is reversed to break out the pipe string or casing.

Claims

We claim:

1. A system for use on a tower for removing from and placing pipe in a well, the pipe having a coupling of larger outside diameter than the outside diameter of the remainder of the pipe comprising: a vertically movable power head mounted on the tower, the power head having means for connecting a pipe coupling to the power head; a pulley system comprising coaxial spaced apart sheaves mounted on and extending below the power head and a cable extending around each sheave with one end anchored to the tower and the free end extending downwardly from the sheave; a pipe transfer elevator attached to the free ends of the cables, the pipe transfer elevator having means for attaching the transfer elevator to the free ends of the cables and an arcuate portion, the space between the extremities of the arcuate portion being such that the arcuate portion may fit over the smaller diameter portion of the pipe but the coupling will be contained in the arcuate portion after the arcuate portion has been fit over the small diameter portion and then pulled over the coupling, the arcuate portion also having a radially extending arcuate shoulder adapted to contact the bottom edge of the coupling; a pair of pivotable pipe string holding members mounted on a platform of the tower each pipe string holding member being a semi-circular shoulder adapted to be contacted by the bottom edge of a pipe coupling for support of the pipe string, each pipe holding member also having an outside portion tapering downwardly and inwardly at an angle of approximately 45.degree. to the horizontal, when the pipe string holding member is positioned to hold a pipe string, each pipe string holding member also being constructed so that when it is pivoted to permit the vertical movement of the pipe string, said tapering portion will lie flat against a flat pipe string holding member support.

2. A system for use on a tower for removing from and placing pipe in a well, the pipe having a coupling of larger outside diameter than the remainder of the pipe, comprising: a power head movable vertically and mounted on the tower; a pulley system connected to the power head and vertically movable with the power head and comprising coaxial spaced apart pulleys mounted on the power head; pipe transfer lines extending around the pulleys and constituting part of the pulley system, the pipe transfer lines extending around the pulleys in a direction such that the free ends of the pipe transfer lines may be moved to a pipe storage area laterally spaced from the tower, and a pipe transfer elevator attached to the free ends of the pipe transfer lines, and adapted to engage the coupling of a pipe and lift the pipe; a platform associated with the tower and having a hole into which the pipe is to be placed or from which the pipe is to be removed; a pipe string holder mounted in the platform hole, said pipe string holder having a pair of pivotable members with each member having a semicircular shoulder formed therein, the shoulder serving to contact the bottom of the pipe coupling to support the pipe string, each pipe string holder also having an outside portion tapering downwardly and inwardly at an angle of approximately 45.degree. to the horizontal when the pipe string holder is positioned to hold a pipe string, each pipe string holder also being constructed so that when it is pivoted to permit the vertical movement of the pipe string, said tapering portion will be flat against a flat pipe string holding member support.