SHAPE MEMORY MATERIAL SEALS

Abstract

The invention relates to a shape memory sleeve to create an annular tightness. More precisely, the invention relates to a ring to provide tightness, made from shape memory alloy material and including an interior annular portion and an exterior annular portion, comprising at least one annular groove or one annular rib on its interior annular portion.

Description

FIELD OF THE INVENTION

This invention relates to tubings and seals for application in the petroleum sector and more particularly the invention comprises forming an annular tightness via a shape memory sleeve.

PRIOR ART

In the petroleum sector, each tool, whether for permanent use (installation at the bottom of a well for permanent use) or for use when it is taken down to the bottom of the well, must withstand rather drastic temperature and pressure constraints, which implies that the tightness for these tools is today formed substantially via welding. The tightness protects the electronics or the cabling against well environment. In case of a failure of the electronics, disassembly becomes complicated and risky since the welds must be ground, running the risk of destroying the entire tool, and the involved parts must be machined and the welding procedure must be started again on site, calling on an outsider welder.

The purpose of the invention is to replace certain annular tight welds of subsets that are complex and difficult to move and which can only be performed on site, with a tight obtained via press fit of a shape memory sleeve. The assembly of the subset can be carried out in a workshop and the press fit using a hot air gun on site or in the workshop, as is convenient. As such, the major advantages are to simplify assembly in the field, reduce the overall cost and assembly time.

SUMMARY OF THE INVENTION

The invention puts forth a ring for providing tightness, made of a shape memory alloy material and including an interior annular portion and an exterior annular portion, and comprising at least one annular groove or one annular rib on its interior annular portion. This ring can more preferably include several annular grooves or annular ribs on its interior annular portion.

In another embodiment, the invention discloses a plug for providing tightness, made of a shape memory alloy material and comprising an exterior annular portion, and comprising at least one annular groove or one annular rib on its exterior annular portion. This plug can more preferably comprise several annular grooves or annular ribs on its interior annular portion.

Another aspect of the invention proposes a method for realizing the tightness of a well-bottom tool, comprising the step of using an element such as described previously.

A method for realizing the tightness of a well-bottom tool is also disclosed, comprising the selection of two elements to be assembled in a tight manner, the selection of a ring made of a shape memory alloy material in its non permanent mode to assemble said elements in a tight manner, the realization of at least one annular rib on the interior portion of said ring and the positioning of said ring in permanent mode by heating to a given temperature such that said ring provides the tightness of said two elements. Incidentally, an annular groove can also be used; a combination of the two groove/rib on the two elements is also possible.

Then, a method for realizing the tightness of a well-bottom tool is also disclosed, comprising the selection of two elements to assemble in a tight manner, the selection of a ring made of a shape memory alloy material in its non permanent mode in order to assemble said elements in a tight manner, the realization of at least one annular rib on one of the two elements and the positioning of said ring in permanent mode by heating to a given temperature such that said ring provides the tightness of said two elements. Incidentally, an annular groove can also be used; a combination of the two groove/rib on the two elements is also possible.

Finally, a method for realizing the tightness of a well-bottom tool is also disclosed, comprising the selection of an element with holes to plug in a tight manner, the selection of a plug made of a shape memory alloy material in its non permanent mode to fill and seal said hole of the element, the realization of at least one annular rib on said plug and the positioning of said plug in said hole in permanent mode by heating to a given temperature such that said plug provides the tightness of the element with holes. Incidentally, an annular groove can also be used; a combination of the two groove/rib on the two elements is also possible.

The preceding methods more preferably include a shape memory alloy material which is Nickel Titane Niobium with 14% niobium and the given temperature is approximately 165° C.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the invention can be understood with more detail in the attached drawings:

FIG. 1 shows machine-tooled ribs inside the ring.

FIG. 2 shows machine-tooled ribs inside a support.

FIG. 3 shows machine-tooled ribs on any metallic support.

FIG. 4 shows an example of a plug relating to the invention.

FIG. 5 shows an electrical connection relating to the invention.

DETAILED DESCRIPTION

The material used as a shape memory alloy is Nickel Titanium Niobium with 14% niobium NiTiNb. This material has the particularity of starting from a dimensional state A, via low-temperature deformation, it is then changed to a dimensional state B (B being higher than A). It remains in state B at room temperature and this, up to 50° C. In this state B, it can therefore be used and assembled on the well tools. Then, by heating it to 165° C. it will return to its dimensional state A, that it will maintain within a temperature range of −60° C. to +300° C.

The tightness is formed by a metal-on-metal tightness realized by annular grooves or ribs. This tightness is maintained by a press fitted ring. The ribs are machine tooled on the ring. Realization of the tightness is provided by ribs and the maintaining of this tightness is provided by a press fitted ring made from shape memory alloy (SMA). Effectively, the tightness is realized by crushing the annular rib on the tubular support. FIG. 1 shows annular ribs 3 machine tooled inside SMA ring 1. By heating the ring, the latter decreases in diameter and squeezes the ribs on tube 2 in order to form the tightness.

In a second embodiment, the same tightness can be realized by machining the ribs on the support rather than on the ring. FIG. 2 shows ribs 3 machine tooled inside a support 4. By heating ring 1, the latter decreases in diameter and squeezes the ribs on a ‘¼ liner’ 5 and forms the tightness.

In a third embodiment, a tightness can also be realized on composite or plastic materials such as PEEK (registered trademark), by machining the ribs on the metallic support then by covering the whole with a plastic tube and by maintaining the tightness via the press fit of the SMA ring. FIG. 3 shows the machine-tooled ribs 3 on a metallic tube 2, a plastic tube 6 covers the ribs. By heating ring 1, the diameter of the latter decreases and squeezes the tube on the ribs and forms the tightness.

In a fourth embodiment, a tightness can also be realized with a plug, by machine tooling ribs on the plug. The plug is made from SMA. The diameter of the plug increases after heating and forms thanks to the ribs, the tightness in its housing. FIG. 4 shows an example of an SMA plug 10, by heating the plug its length decreases and its diameter increases and forms the tightness of a support 12.

In a fifth embodiment, the squeezing of the ring can be used to realize an electrical continuity of a contact on another contact. This avoids brazing them together. FIG. 5 shows an electrical connection 7, instead of forming the electrical continuity by a braze (which is done for permanent tools). An SMA ring 1 is used to squeeze the split electrical contact 21 on the second electrical contact 20 in such a way as to realize the electrical continuity as well as its mechanical maintaining. The advantage is to simplify the procedure and avoid recourse to manual know-how for the braze.

Claims

1. Ring for providing tightness, made of a shape memory alloy material and including an interior annular portion and an exterior annular portion, and comprising at least one annular groove or one annular rib on its interior annular portion.

2. Ring according to claim 1, comprising several annular grooves or annular ribs on its interior annular portion.

3. Plug for providing tightness, made of a shape memory alloy material and comprising an exterior annular portion, and comprising at least one annular groove or one annular rib on its exterior annular portion.

4. Plug according to claim 3, comprising several annular grooves or annular ribs on its exterior annular portion.

5. Method for realizing the tightness of a well-bottom tool, comprising the step of using an element such as described in claim 1.

6. Method for realizing the tightness of a well-bottom tool, comprising the selection of two elements to assemble in a tight manner, the selection of a ring made of shape memory alloy material in its non permanent mode in order to assemble said elements in a tight manner, the realization of at least one annular rib on the interior portion of said ring and the positioning of said ring in permanent mode by heating to a given temperature such that said ring provides the tightness of said two elements.

7. Method for realizing the tightness of a well-bottom tool, including the selection of two elements to be assembled in a tight manner, the selection of a ring made from shape memory alloy material in its non permanent mode in order to assemble said elements in a tight manner, the realization of at least one annular rib on one of the two elements and the positioning of said ring in permanent mode by heating to a given temperature such that said ring provides the tightness of said two elements.

8. Method for realizing the tightness of a well-bottom tool, including the selection of an element with holes to plug in a tight manner, the selection of a plug made from shape memory alloy material in its non permanent mode to fill said hole of the element in a tight manner, the realization of at least one annular rib on said plug and the positioning of said plug in said hole in permanent mode by heating to a given temperature such that said plug provides the tightness of the element with holes.

9. Method according to claim 6, wherein the shape memory alloy material is Nickel Titanium Niobium with 14% niobium and the given temperature is approximately 165° C.