Retrievable seal guide

Abstract

A retrievable seal guide (RSG) for installing a seal stem in a polished bore receptacle. The RSG has an outer grapple. Inside the grapple is a mandrel. At the end of the RSG is a bullet nose guide. The mandrel is spring loaded with a spring placed under the grapple Near the rear end of the guide is a plug with an o-ring. Note that the bullet nose has an opening formed in it. A channel is also formed down the length of the device. Note too that for tight formations of non-perforated liners the plug can be replaced with a stainless-steel ball that acts as a check valve. As the RSG is pulled out, the guide is pulled back, which compresses the spring forcing the mandrel back until a cam clears the collapsible fingers on the grapple, which allows the RSG to be withdrawn.

Claims

1. A retrievable seal guide for inserting a seal stem into a polished bore receptacle, using a setting tool, comprising: a) a guide, having a front and a back, having a tapered head at the front, and a rear body at the back; b) a mandrel, having an elongated body having a front and a back, the front of said mandrel being connected to the rear body of said guide, the back of said mandrel having a threaded cylinder, and also having a cam formed thereon; c) a grapple, having a front portion and a rear portion that fits around both the mandrel and the rear body of the guide, said grapple also having a slot formed in the back portion thereof, and a set of collapsible fingers formed about the rear portion thereof, said set of collapsible fingers being in operable communication with the cam on said mandrel; d) wherein, said guide, mandrel and grapple are assembled into a unit and placed into said seal stem, having a top and a bottom, such that the guide, mandrel and grapple pass through the seal stem until the grapple fingers extend and are held by the cams on said mandrel, thereby preventing said seal stem to slide downwardly on said retrievable seal guide until said seal stem is positioned in said polished bore receptacle, and further wherein said setting tool is attached to said threaded cylinder at the back of said mandrel, for insertion of said unit and said seal stem into said polished bore receptacle; e) and further wherein after said seal stem is positioned in said polished bore receptacle the setting tool is then pulled upwards, causing said mandrel and said guide to be pulled upwards simultaneously, said upward movement causing said cam on said mandrel to be moved upwardly until said cam is clear of said collapsible fingers on said grapple, causing said collapsible fingers to collapse inwardly, allowing said grapple to pass through said seal stem with said mandrel and said guide until said grapple is completely removed from said seal stem.

2. The retrievable seal guide of claim 1 further comprising: a spring positioned in said grapple such that said spring is in operable communication with the rear body of said guide.

3. The retrievable seal guide of claim 2 having a first position, wherein such spring is expanded, for insertion and a second position, wherein such spring is compressed, for retrieval.

4. The retrievable seal guide of claim 3 wherein when said spring is compressed, said cam on said mandrel is positioned off of said collapsible fingers such that said collapsible fingers collapse into said grapple.

5. The retrievable seal guide of claim 2 wherein the guide further includes: a) an opening connected to a channel formed in said guide; and b) a means of sealing said channel in operable communication with said channel.

6. The retrievable seal guide of claim 5 wherein the means of sealing said channel in operable communication with said channel comprises a plug that has an O-ring installed around said plug.

7. The retrievable seal guide of claim 5 wherein the means of sealing said channel in operable communication with said channel comprises a ball.

8. The retrievable seal guide of claim 2 further comprising a set screw that locks the mandrel to the guide.

9. The retrievable seal guide of claim 1 wherein the guide further includes: a) an opening connected to a channel formed in said guide; and b) a means of sealing said channel in operable communication with said channel.

10. The retrievable seal guide of claim 9 wherein the means of sealing said channel in operable communication with said channel comprises a plug that has an O-ring installed around said plug.

11. The retrievable seal guide of claim 9 wherein the means of sealing said channel in operable communication with said channel comprises a ball.

12. The retrievable seal guide of claim 1 further comprising a set screw that locks the mandrel to the guide.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a detail view of a well casing having a liner and a polished bore receptacle as prior art.

(2) FIG. 2 is an side view of mule shoe as prior art.

(3) FIG. 3 is a detail view of the RSG and seal stem shown in a run in position.

(4) FIG. 3a is a detail view of the RSG and seal stem showing the seal stem positioned at the bottom of the PBR.

(5) FIG. 4 is a detail view of the RSG being retrieved.

(6) FIG. 5 is a detail view of the seal stem that is left in the hole.

(7) FIG. 6 is a partial cut-away view of the preferred embodiment of the RSG showing the mandrel in a partial cutaway view.

(8) FIG. 6a is a side detail partial cutaway view showing the cams and mandrel partially withdrawn and the collapsible fingers collapsed on the RSG.

(9) FIG. 7 is a cross-sectional view of a second embodiment of the RSG.

(10) FIG. 8 is a detail view of the grapple in isolation.

(11) FIG. 9 is a detail of the guide in isolation.

(12) FIG. 10 is a detail of the mandrel in isolation.

DETAILED DESCRIPTION OF THE INVENTION

(13) Referring now to the figures and particularly FIGS. 3, 3a, 4 and 5, FIG. 3 is a detail view of the RSG and seal stem, shown in a run-in position. Here, the RSG 10 is shown passing through a PBR 102 with a seal stem 11 attached. The RSG 10 enters the liner until the seal stem 11 reaches the bottom of the PBR 102, as shown in FIG. 3a. FIG. 4 is a detail view of the RSG being retrieved. In this figure, the RSG 10 is shown being removed from the well. The PBR 102 is shown as before. The seal stem 11 is shown remaining in the PBR while the guide is removed. Note the setting tool 106 is shown in this drawing. Details of the exact removal process are discussed below. FIG. 5 is a detail view of the seal stem that is left in the hole. Here, the PBR 102 is shown with the seal stem 11 remaining in place. The rest of the RSG and setting tools are gone.

(14) FIG. 6 is a side, partially cutaway view of the RSG 10. As shown, the main external components of the RSG 10 are as follows. First, is the guide 12, at the end of the tool. The guide 12 fits into a grapple 13 that has a slot 14 formed in it, as shown. A mandrel 15, here shown partially cutaway to show the open interior of the mandrel, fits inside the grapple 13. The mandrel is internally connected to the guide 12 and is spring loaded so that then the mandrel 15 is pulled upwards, the guide 12 is pulled up into the grapple. As discussed below, a cam system causes a set of collapsible fingers 16 formed on the grapple to collapse inward, allowing the grapple to fit within the seal stem. Normally the fingers prevent the seal stem 11 from falling down off the end of the RSG. When the RSG is retrieved, these fingers collapse, as discussed below. Once the fingers are collapsed, the RSG can be pulled through the seal stem and out of the well. Each of the components discussed above are discussed in greater detail below.

(15) FIG. 7 is a cross-sectional view of a second embodiment of the RSG 10. In this view, the mandrel 15 is shown attached to the guide 12. As discussed above, the guide 12 has a tapered head 12a, and a rear body 12b. Near the end of the guide is an opening 12c, through which fluids can flow. The opening 12c is connected to a channel 12d. At the end of the channel 12d is a plug 12e, which acts as a solid seat. The plug 12e has an O-ring 12f. The plug 12e is used to prevent fluid from entering the guide. Because, in most cases, the liner is perforated, fluid in the liner can be pushed down and out through the perforations, preventing excess pressure and allowing the seal stem to seat.

(16) The grapple 13 fits around both the mandrel 15 and the guide 12. A spring 17 fits between the mandrel 15 and the grapple 13b as shown. A set screw 18 locks the mandrel 15 to the guide 12 to prevent the threads 12g, which secure the guide 12 to the mandrel 13, from rotating.

(17) At the rear end of the mandrel 15 are threads 19 that allow the mandrel (and thus the RSG) to be attached to a setting tool (see e. g., FIG. 4). When the setting tool pulls on the mandrel 15, the mandrel and guide move within the grapple 13 in the direction of the arrow shown. This causes the spring 17 to compress. It also causes the cam 20 to move back (see inset FIG. 6a). As shown, once the cam 20 passes the fingers 16, a gap is formed that allows the fingers to bend inwardly to contact the mandrel, which allows the fingers to fit inside the seal stem. See FIG. 6a. Normally the fingers prevent the seal stem 11 from falling down off the end of the RSG. When the RSG is retrieved, these fingers collapse, as discussed above. Once the fingers are collapsed, the RSG can be pulled through the seal stem and out of the well.

(18) FIG. 6a shows a portion of the mandrel 15 and grapple 13 showing the collapsible fingers 16 and the seal stem 11. Once the cam 20 is pulled back, the fingers 16 have room to collapse so that the RSG can pass into the seal stem 11 and then be pulled from the well.

(19) FIG. 8 is a detail view of the grapple 13 in isolation.

(20) FIG. 9 is a detail of the guide 12 in isolation.

(21) FIG. 10 is a detail of the mandrel 13 in isolation.

(22) FIG. 7 is a cross-sectional view of a second embodiment of the RSG. In this view, the RSG is virtually identical to the previous embodiment. However, in this embodiment, the block 12e is replaced by a steel ball 12h. The ball is another one of the means of sealing the channel and is in operable communication with the channel. This ball is used as check valve in tight formations or non-perforated liners. The fluid in the liner pushing against the ball, floats the ball out of its seat allowing the pressure to drop and allowing seal stem to seat.

(23) The RSG allows for easy insertion of seal stems with complete retraction of the RSG. These is no problem setting the seal stem in the PSR. This saves time and money.

(24) The present disclosure should not be construed in any limited sense other than that limited by the scope of the claims having regard to the teachings herein and the prior art being apparent with the preferred form of the invention disclosed herein and which reveals details of structure of a preferred form necessary for a better understanding of the invention and may be subject to change by skilled persons within the scope of the invention without departing from the concept thereof.