WELLHEAD REMOVAL APPARATUS AND METHOD

Abstract

Apparatus for use with a waterjet pump, a wellhead projecting above ground and a casing disposed below ground, the casing defining a longitudinal axis, the apparatus comprising, in use: a mount coupled to the wellhead;a platform coupled to the mount for rotation about a spin axis coincident with the longitudinal axis;a carrier coupled to the platform for rotation therewith, the carrier extending from an end disposed adjacent the platform, through the spin axis, to an end disposed adjacent the casing;a nozzle to which the carrier extends, which is coupled to the pump and which is directed radially with respect to the spin axis;a mechanism for causing the carrier to rotate; andan arrangement supporting the carrier for pivotal movement about a pivot axis perpendicular to the spin axis such that the nozzle is held in cutting position to the casing during rotation, to sever said casing.

Description

FIELD

The invention relates to the field of well head removal.

BACKGROUND

Mothballed wells with protruding heads keep a great deal of arable land unworked worldwide.

SUMMARY OF THE INVENTION

Forming one aspect of the invention is apparatus for use with a waterjet pump coupled to a supply of cutting fluid and with a well remnant, the well remnant having a head portion projecting above the ground and a tubular casing portion disposed within the ground, the casing defining a longitudinal axis.

The apparatus comprises:

• • a mount coupled in use to the head portion;
  • a platform rotatably coupled in use to the mount for rotation about a spin axis substantially parallel to and coincident with the longitudinal axis;
  • an elongate nozzle carrier coupled to the platform for rotation therewith, the carrier extending from a fixed end disposed adjacent the platform, through the spin axis, to a terminal end disposed adjacent the tubular casing;
  • a nozzle to which the nozzle carrier extends, which is coupled in use to the waterjet pump and which is directed substantially radially with respect to the spin axis;
  • a mechanism for causing the carrier to rotate in use; and
  • an arrangement supporting the nozzle carrier for pivotal movement about an pivot axis substantially perpendicular to the spin axis, the arrangement being such that the nozzle is held in cutting position to the casing during said rotation, to sever said casing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of apparatus according to an exemplary embodiment of the invention in use, the use being indicated in phantom;

FIG. 2A is an enlarged view of encircled area 2A of FIG. 1;

FIG. 2B is a view of the structure of FIG. 2A from another vantage point;

FIG. 2C is a view of the structure of FIG. 2A from another vantage point;

FIG. 3A is an enlarged view of encircled area 3A of FIG. 1;

FIG. 4 is an exploded view of the structure of FIG. 1;

FIG. 5A is an enlarged view of encircled area 5A of FIG. 4;

FIG. 5B is a view of the structure of FIG. 5A from another vantage point;

FIG. 5C is a view of the structure of FIG. 5A from another vantage point;

FIG. 5D is a view of the structure of FIG. 5A from another vantage point;

FIG. 6 is an enlarged view of the structure of encircled area 6 of FIG. 4;

FIG. 7 is a view of a prior art well remnant;

FIG. 8 is a view of the structure of FIG. 8 mounted to the structure of FIG. 7;

FIG. 9 is a view of the structure of FIG. 5A mounted to the structure of FIG. 8;

FIG. 10 is a view of the structure of FIG. 10 mounted to the structure of FIG. 9;

FIG. 11 is a view similar to FIG. 10;

FIG. 11A is a top view of the structure of FIG. 11;

FIG. 11B is a view of encircled area 11B of FIG. 11;

FIG. 12 is a view similar to FIG. 11 but with the structure of FIG. 9 rotated 90°;

FIG. 12A is a top view of the structure of FIG. 12;

FIG. 12B is a view of encircled area 11B of FIG. 12;

FIG. 13 is a view similar to FIG. 12 but with the structure of FIG. 9 rotated 90°;

FIG. 13A is a top view of the structure of FIG. 13;

FIG. 13B is a view of encircled area 11B of FIG. 13;

FIG. 14 is a view similar to FIG. 13 but with the structure of FIG. 9 rotated 90°;

FIG. 14A is a top view of the structure of FIG. 14; and

FIG. 14B is a view of encircled area 11B of FIG. 14.

DETAILED DESCRIPTION

Apparatus 20 according to an exemplary embodiment of the invention is shown in the drawings and will be seen to include a mount 22, a platform 24, a nozzle carrier 26, a nozzle 28, a mechanism 30 and an arrangement 32.

The mount 22 is a planar structure having a central aperture 34 and a plurality of clamps 36.

The platform is defined by one 38 of the rings of a slewing bearing; the slewing bearing also has another ring 40 coupled to the mount, thereby to permit rotation of the platform about a spin axis X1-X1 defined by the slewing bearing.

The nozzle carrier is an elongate member defining a longitudinal axis X2-X2, having a fixed end 42 and a terminal end 44 and extending from the fixed end, through the spin axis, to the terminal end, the fixed end being disposed adjacent to the mount and offset from the spin axis X1-X1

The nozzle is a water jet nozzle.

The mechanism 30 comprises a gear 46 driven by a motor 48, the gear being in mesh with the one ring of the slewing bearing, thereby to provide for rotation of the platform.

The arrangement 32 supports the nozzle carrier for pivotal movement about a pivot axis X3-X3 substantially perpendicular to the spin axis and will be seen to include a receiving plate 50 having a through passage 52 for receiving the nozzle carrier and an elastomeric pivot bearing 54 coupling the receiving plate to the platform.

The apparatus is used with a waterjet pump (not shown) coupled to a supply of cutting fluid (not shown) and with a well remnant 100, the well remnant 100 having a head portion 102 projecting above the ground and a tubular casing portion 104 disposed within the ground, the casing defining a longitudinal axis X4-X4.

In use:

• • the mount is coupled to the head portion, as shown in FIG. 8
  • the nozzle is coupled to the waterjet pump and the supply of cutting fluid; in the embodiment shown, the coupling is provided by a helical coil 106
  • the mechanism is operated to cause the nozzle carrier to rotate; and
  • the arrangement holds the nozzle in cutting position to the casing, thereby to sever said casing.

Whereas a specific embodiment is shown and described, it will be appreciated that variations in use and structure are possible. Without limitation in this regard, it will be appreciated that the apparatus can be used with casings of varying diameter, merely by adjusting the offset between the aperture in the receiving plate and the pivot axis; a plurality of equally spaced mounting holes 56 in the receiving plate are provided for this purpose. Accordingly, the invention should be understood to be limited only by the accompanying claims, purposively construed.

Claims

1. Apparatus for use with a waterjet pump coupled to a supply of cutting fluid and with a well remnant, the well remnant having a head portion projecting above the ground and a tubular casing portion disposed within the ground, the casing defining a longitudinal axis, the apparatus comprising: a mount coupled in use to the head portion;a platform rotatably coupled in use to the mount for rotation about a spin axis substantially parallel to and coincident with the longitudinal axis;an elongate nozzle carrier coupled to the platform for rotation therewith, the carrier extending from a fixed end disposed adjacent the platform, through the spin axis, to a terminal end disposed adjacent the tubular casing;a nozzle to which the nozzle carrier extends, which is coupled in use to the waterjet pump and which is directed substantially radially with respect to the spin axis;a mechanism for causing the carrier to rotate in use; andan arrangement supporting the nozzle carrier for pivotal movement about an pivot axis substantially perpendicular to the spin axis, the arrangement being such that the nozzle is held in cutting position to the casing during said rotation, to sever said casing.