Weight Spacer Apparatus

Abstract

Weight spacer apparatus is disclosed which comprises a carrier which is tubular in shape and a spacer tube which is also tubular in shape for insertion into the carrier. The weight spacer apparatus according to the present invention further comprises a plurality of weight bars which may be inserted into the spacer tube after the spacer tube is inserted into the carrier and which are also removable from the spacer tube. In one embodiment, a weight tray is inserted into the spacer tube for receiving the weight bars, and the weight tray may be fabricated from half-round tubing with a welded plate to cover the diametric opening. In another embodiment, a center plate is attached inside the spacer tube along the length of the spacer tube to divide the spacer tube into first and second compartments. The first compartment comprises a weight tray for receiving the plurality of weight bars, and the portion of the spacer tube opposite the first compartment has openings formed in it to receive shaped charges.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is an elevation view in partial cross-section taken along the longitudinal axis of one embodiment of weight spacer apparatus of the present invention.

FIG. 2 is a perspective view of the weight tray 14 of FIG. 1.

FIG. 3 is an elevation view in partial cross-section view taken along the longitudinal axis of a second embodiment of weight spacer apparatus according to the present invention.

FIG. 4 is an elevation view in partial cross-section of the apparatus of FIG. 3 where the apparatus of FIG. 3 has been rotated 90°.

FIG. 5 is an elevation view in partial cross-section illustrating the embodiment of FIG. 4 loaded with weights.

FIG. 6 is cross-sectional view of weight spacer apparatus of the present invention with shaped charges installed in the openings 29 shown in FIGS. 3 and 4.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

It will be appreciated that the present invention may take many forms and embodiments. In the following description, some embodiments of the invention are described and numerous details are set forth to provide an understanding of the present invention. Those skilled in the art will appreciate, however, that the present invention may be practiced without those details and that numerous variations and modifications from the described embodiments may be possible. The following description is thus intended to illustrate and not to limit the present invention.

With reference first to FIG. 1, there is illustrated one embodiment of a weight spacer assembly 10 in accordance with the present invention. Weight spacer assembly 10 comprises a carrier 11 which is tubular in shape and a spacer tube 12 which is also tubular in shape and which is for insertion into the carrier 11. A plurality of weight bars 13 may be placed in the spacer tube 12 after the spacer tube is inserted in the carrier 11. In accordance with the present invention, these weight bars 13 are also removable from the spacer tube 12.

With reference to FIGS. 1 and 2, the weight bars 13 may be placed in a weight tray 14 which is made from half-round tubing material 14a that has a welded plate 14b covering the diametric opening. One end of the weight tray 14 is permanently blocked by an end plate (not show). The other end of the weight tray 14 is open before the weight bars 13 are inserted into the weight tray and is blocked by a lower end plate (not shown) after the weight bars 13 are inserted.

With reference now to FIGS. 3-6, another embodiment of weight spacer apparatus 20 in accordance with the present invention is illustrated. Weight spacer apparatus 20 comprises a tubular carrier 21 and a tubular spacer tube 22, and the spacer tube 22 is for insertion into carrier 21. A center plate 23 is welded inside the spacer tube 22 and divides the spacer tube 22 into two compartments 25 and 26. Weight bars 27 may be placed in or removed from compartment 25 and compartment 25 thus provides the function of a weight tray. Upper and lower alignment plates 40 and 41 function to retain weight bars 27 in compartment 25.

Openings 29 may be formed in that portion of the spacer tube 22 which is opposite from compartment 25. These openings 29 are for receiving shaped charges 30, such as illustrated in FIG. 6. The structure and operation of shaped charge 30 is well-known to those skilled in the art. A detonating cord 35 runs from one end of the weight spacer apparatus 20 to the other end and is used to connect the plurality of shaped charges 30 that are installed in openings 29 into the ballistic train of a perforating string.

Still referring to FIGS. 3-6, a plurality of additional openings 32 may also be made in that portion of the spacer tube 22 which is opposite from compartment 25. These openings 32 are made to facilitate the installation of shaped charges 30 and to reduce the weight on that portion of the spacer tube opposite compartment 25 so that the requisite at torque may be achieved to orient the perforating string appropriately.

The embodiments of weight spacer apparatus 20 illustrated in FIGS. 3-6 permits the user to obtain a perforating capability that has not heretofore existed. For example, the weight spacer apparatus 20 provides an orienting apparatus with perforating capability, which thus increases the perforating capability of the perforating string in which it is utilized.

Claims

1. Weight spacer apparatus, comprising: a carrier which is tubular in shape;a spacer tube which is tubular in shape and which is for insertion into the carrier; anda plurality of weight bars which may be placed in the spacer tube after the spacer tube is inserted in the carrier and which are removable from the spacer tube.

2. The weight spacer apparatus of claim 1, wherein the spacer tube comprises a weight tray for receiving the weight bars.

3. The weight spacer apparatus of claim 1, wherein it further comprises a center plate which is attached inside the spacer tube along the length of the spacer tube to divide the spacer tube into first and second compartments.

4. The weight spacer apparatus of claim 3, wherein the first compartment of the divided spacer tube is for receiving the plurality of weight bars.

5. The weight spacer apparatus of claim 3, wherein it further comprises a detonating cord disposed in the second compartment of the divided spacer tube.

6. The weight spacer apparatus of claim 3, wherein the spacer tube has openings formed in the portion opposite the first compartment for receiving shaped charges.

7. The weight spacer apparatus of claim 6, further comprising a shaped charge which is installed in each of said openings in the spacer tube.

8. The weight spacer apparatus of claim 7, wherein it further comprises a detonating cord disposed in the second compartment of the spacer tube for connecting to the shaped charges.

9. A perforating string, comprising: at least one perforating gun section; anda weight spacer comprising: a carrier which is tubular in shape;a spacer tube which is tubular in shape and which is for insertion into the carrier; anda plurality of weight bars which may be placed in the spacer tube after the spacer tube is inserted in the carrier and which are removable from the spacer tube.

10. The perforating string of claim 9, wherein the spacer tube comprises a weight tray for receiving the weight bars.

11. The perforating string of claim 9, wherein the weight spacer comprises a center plate which is attached inside the spacer tube along the length of the spacer tube to divide the spacer tube into first and second compartments.

12. The perforating string of claim 11, wherein the first compartment of the divided spacer tube is for receiving the plurality of weight bars.

13. The perforating string of claim 11, wherein the spacer tube has openings formed therein in the portion opposite the first compartment for receiving shaped charges.

14. The perforating string of claim 13, further comprising a shaped charge installed in each of the openings in the spacer tube.

15. The perforating string of claim 14, further comprising a detonating cord disposed in the second compartment of the spacer tube for connecting the shaped charges into the ballistic train of the perforating string.

16. A method of forming a weight spacer assembly for use in a perforating string, comprising: inserting a spacer tube into a tubular carrier, said spacer tube including a weight tray; andinserting weight bars into the weight tray after the spacer tube has been inserted into the carrier.

17. The method of claim 16, wherein it further comprises the step of: installing shaped charges in the spacer tube before the spacer tube is inserted into the carrier.