Method of sealing casing pipes at screwed joints and at through damages. RU patent 2508444.

FIELD: oil-and-gas industry.

SUBSTANCE: impermeable shell is lowered on string or cable to leaky thread or through damage to make it tightly abut on pipe wall perimeter. Said shell is composed og coiled sheet metal. 2-3 mm-thick sheet metal is made from spring steel, e.g. 60C2 or 65"Г" and riveted in the coil by two low-strength rivets. Rivets are cut at the burst of charge arranged inside said coil opposite leaky joint. Then, metal sheet is forced by inner elasticity to uncoil and to be pressed against casing pipe inner surface. Metal sheet outer surface is pre-coated with soft deformable material, for example, rubber, or gasket of the same material is fitted on coil outer side to be deformed by elasticity to seal the space between metal sheet and casing pipe inner wall.

EFFECT: efficient and reliable sealing.

1 cl, 2 dwg

The invention relates to methods of sealing of casing pipes used in the oil and gas industry.

Known way to restore casing tightness wells [1], which consists in the installation profile by the explosion, and before the explosion leveled by creation of a hydraulic pressure.

The disadvantage of this method is that to generate sufficient pressure explosion, in which the profile would ensure the tightness of the casing, more power is required explosive. And this can cause in the well of, or damage to the column.

A device for repair casing [2]containing the descent on the cable housing, fixing the plaster and metal explosive explosion which patch, under the pressure of the explosion, pressed against the wall of the casing, closing the channel leakage. This device uses a method for elimination of leaks using the patch.

The disadvantage of this method is that with a sufficiently large power of the explosion, that it is necessary to compress the patch to the wall of the pipe casing, display of or damage to the pipe casing.

Closest to the proposed is the way to completion of the construction of wells [3]including the descent on the pillar of pipes in pre-extended interval of productive layer of impermeable membrane in the form of rolled up sheet metal and installation with a possibility of a snug fit to the borehole walls around the perimeter through assessed pre-leaf springs at equal distances from each other, from the margins of the sheet metal.

The disadvantage of this method of sealing is the following. When using leaf springs efforts from them will act only on the part of the surface of a metal sheet, not on the entire surface. Therefore, where effort by the spring there, there's going to be a tight fit, and a loose, that will not provide air-tight (elimination of leakage) of the casing.

The objective of the invention is to eliminate the shortcomings identified in the above-mentioned methods, including in the prototype.

The technical challenge is to develop ways of providing a reliable sealing of casing at eliminating leaks in threaded connections or in the form of through holes.

It is known [4]that the leakage screw connections columns pipes is the cause for the missing gas () in 80% of cases, which leads to large losses of gas and is a dangerous phenomenon. The presence of holes in the casing has the same effects. Therefore it is desirable to eliminate the existing casing leakage.

The problem is solved by the described way, including descent on a column pipe or on a cable to the location of the leak on a thread or the through hole, impervious membrane in the form of rolled up sheet metal and installation with a possibility of a snug fit to the internal pipe walls around the perimeter. What is new is the sheet metal thickness of 2-3 mm and more are made of spring steel, for example steel 602 or 65G, and the roll is fixed two rivets that during the explosion of the weak capacity of the charge inside the coil casing, opposite the site of the leak, cut off, and sheet metal under the action of internal forces of elasticity, spinning up and pressed tightly to the inner surface of the casing, and on the external surface of the sheet metal pre-put a layer of soft deformable material, such as rubber, or put on a roll with the outside cylindrical strip of the same material, which is being deformed under the action of forces of elasticity from the overlay, provides a seal between established by the metal plate (plate) and the inner surface of the casing.

Analysis of selected known technical solutions found in the course of the patent research, shows that on the filing date, objects, described such a set of essential features and that their use would lead to the achievement of a higher technical result, as proposed, is not found, allows to make a conclusion on the compliance of the declared object of the criteria of «Novelty» and «Inventive step». And its industrial applicability is confirmed by a complete description of its implementation.

Presented drawings explain the essence of the invention, which figure 1 shows the position of the sheet metal roll, anchored two rivets and lowered in the casing by a rope below through hole. Figure 2 shows the position of the sealing sheet metal (pad) on the through hole with spring gasket.

Figure 1 shows a longitudinal section of the casing 1, which has a hole through 4. Sheet metal (cover) rolled and sealed in this position the two rivets 13. In worksheet performed three holes 3 for connection to the grid system in the form of a rope 11. For disclosure (deployment) roll is a charge of 12 explosive, which falls on the cable and is located closer to the . During the examination of the casing the location of the leak is determined. Therefore, on this depth and falls sealing sheet metal. However, for the exact location, sheet metal is better to use the camcorder 9. slings 10 (three pieces) connect roll with rope 11. Mark 14 on one of the sling is located opposite the rivets 13 and serves as a reference camcorder - label opposite the hole.

Figure 2 shows the location of the sealing of a sheet 5 of the through hole 4. Gasket 2 is situated between the sheet and the inner surface of the casing. Sealing sheet 5 above and below has tapered slant 6 to reduce the resistance of the transportation of the equipment casing and liquids during overhaul. The gap between 7 side walls, sealing sheet must be minimal (better equal to zero). Inner diameter D EXT. casing must be larger than the outer diameter of the roll D pl. to ensure a smooth descent sealing sheet in the casing.

The proposed method is implemented as follows.

On the surface, knowing the internal diameter of the casing string D EXT. cut out sealing plate (sheet metal), the width of which must be such that the gap 7 was minimal (it is better that he was nothing, but the overlap of the edges to each other in a sealant tapes position is not allowed). This is checked on the tube (the part of the pipe) on the surface, the inner diameter of which is the same as the casing. The height of a page should reliably overlap leaky place, but too much height is unacceptable, since it difficult installation and requires a more solid rivets, and hence the greater the power of the explosive package. In the piece, in its upper part are two holes for rivets 13, size and material of which was picked previously. Also make three holes 3 lines 10. Then the top and bottom sheet carry out education cones 6. After this sealing plate rolled cones inside, and inserts two (to roll is not turned, and he was in the same position) rivet 13 and are to be riveted. After that the roll is inserted into the cylindrical spacer 2 (for example, taken strip, although you can apply a layer of deformable material on the external surface sealing linings). Slings 10 one end fixed in the holes 3, and the other is bound with rope 11, through which the descent pads on a certain depth in the casing (for example comes rope, though descent can be made on the pillar of pipes). Also, at a distance L from the top of the sealing linings is located camcorder 9, which falls on the cable synchronously with sealing plate 5. Near the rivets fixed block explosive 12, cable 8 to fuse which descends from the surface also synchronously descent sealing linings 5. Roll diameter metal sheet D pl. smaller than the inside diameter of the casing pipe that allows you to roll down. Location of the leak in the casing string is predefined by its depth. At this depth, you can omit the sealing sheet metal 5. However, in this case the height of the sheet you want to do several times more than the camera. For example, use the camcorder 9-round view. When approaching leakage (in our case, as an example taken through hole 4) during the descent descent speed decreases, and the collected block slowly goes down. Once the camera 9 is aligned with the holes 4, descent stops. This will then be the turn of a rope 11, and with it, and a roll of duct lining around its axis so that the mark on 14 one of the sling 10 established opposite the hole 4. Then a gap of 7 will be located opposite the opening. Turning should be carried out very slowly, so that by inertia does not get the right position. Then a slow rise of the collected block up on the distance L (this is the distance measured on the surface). At the end of this distance rise stops, and sealing patch 5 (assembled module) occupies the position opposite the hole 4 (4 hole in the middle of the height of sealing sheet 5). Once that happened, cable 8 powered fuse charge 12. There is an explosion, pressure P TCD. is transmitted to the inner surface of the sealing sheet metal, which increases efforts P cf. the rivet 13. Rivet cut off, and rolled into a roll sheet metal under the action of internal forces of elasticity, unwound and stretches pad 2, while the latter lie on the internal pipe surface casing and pin her to the surface will be a metal sheet 5. As a result of the hole through 4 overlaps strip and sheet metal, eliminating leaks. As the forces of elasticity R REM. will continue tightening the grip, because the lining of the plane surface occupied the position of a curved (on the inner surface of the pipe casing), sealing plate 5 will firmly stick to the inner surface of the pipe casing, through the gasket 2, and ensure tightness before the leaking of the place. After this rope 11 begins to rise, but move the sheet metal overlay 2 cannot, due to friction forces between the lug 5 and gasket 2. Slings are made fragile. At the Appendix to him tensile strain they surgeon cuts through it in the place of their attachment to the tightening grip and rise to the surface together with rope 11.

Way of sealing of casing pipes in threaded connections and cross-cutting injuries, including descent on a column pipe or on a cable inside the casing to the location of the leak on a thread or the through hole, impervious membrane in the form of rolled up sheet metal and installation with a possibility of a tight fit to the inner wall of the casing around the perimeter, wherein the sheet metal thickness of 2-3 mm and more are made of spring steel, for example steel 602 or 65G, and the roll is fixed two rivets that during the explosion of the weak capacity of the charge inside the coil casing, opposite the site of the leak, cut off, and sheet metal under the action of internal forces of elasticity, spinning up and pressed tightly to the inner surface of the casing, and on the external surface of the sheet metal pre-put a layer of soft deformable material, such as rubber, or put on a roll with the outside cylindrical strip of the same material, which is being deformed under the action of forces of elasticity from the overlay, provides the seal between the mounted sheet metal-plate and the internal surface of the casing string.