Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B29/00—Cutting or destroying pipes, packers, plugs or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground
  • E21B29/02—Cutting or destroying pipes, packers, plugs or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground by explosives or by thermal or chemical means
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/10—Sealing or packing boreholes or wells in the borehole
  • E21B33/13—Methods or devices for cementing, for plugging holes, crevices or the like
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B37/00—Methods or apparatus for cleaning boreholes or wells
  • E21B37/02—Scrapers specially adapted therefor
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/11—Perforators; Permeators
  • E21B43/116—Gun or shaped-charge perforators

Definitions

• the present invention relates to a tool for handling of wells through a formation, and which shall be taken out of operation by installing a closing plug of a hardenable material, such as concrete, where there is a casing pipe in the well which is cemented towards the wall of the bore hole with a concrete, as defined in the introduction of claim 1 .
• the invention also relates to a special construction of a perforating gun to provide perforations in a pipe in a formation and comprising an extended lance fitted with a number of explosive charges around the circumference and along the length of the lance, and also means for the detonation of the explosive charges. Furthermore, the invention relates to a method as described in the introduction of claim 12 for the closing off of a well including a casing pipe through a formation in that a plug of a hardenable material is established, whereby a section of the casing pipe through the well is perforated and a material that can be hardened is conducted down through the pipe and is brought to flow out through the perforations and make contact with the walls of the original bore hole.
• the invention concerns a tool that is used in connection with the plugging of wells that shall be taken out of operation.
• a well bore is drilled down into the formation, and a casing pipe (production pipe) is set down into the well bore and is secured and stabilised in relation to the walls of the original bore hole in that concrete is sprayed in between the outer wall of the pipe and the wall of the bore hole.
• This three part operation is carried out in that a perforating tool which is fitted with a number of directed explosive charges is lowered down. When these are fired, a set of holes is blasted into the pipe to wash out and partially dissolve the original concrete so that the new and fresh concrete can make a proper direct contact with the rock formation while establishing the plug.
• a cleaning tool that grinds off protruding bits of metal and fibres from the pipe inside, and which are formed as a consequence of the explosion.
• the cleaning tool can be a brush that brushes, rubs or grinds the pipe internally.
• a flushing tool When the pipe is ground and cleaned, a flushing tool is lowered down with an upper and a lower set of gaskets that seal against the inner wall of the pipe. A cleaning fluid is sprayed out between these sets of gaskets, usually containing an acid that can flush loose bits of concrete or possibly directly dissolve the concrete chemically. These bits of concrete and concrete remains is then flushed with the flow of fluid upwards in through the annular space between the pipe in which the tool is suspended from the surface and the inside of the casing pipe.
• the tool according to the invention is characterised in that it comprises an assembled unit of the following three sections: a perforating lance comprising a number of explosive charges which, by detonation, form a row of holes in the pipe and out into the surrounding layer of concrete, a cleaning unit for mechanical cleaning of the inner wall of the pipe at the perforated area and a flushing unit to loosen, dissolve and flush away the hardened cement material between the outer wall of the pipe and the wall of the bore hole.
• the unit is preferably fitted to the end of the operating string or pipe that is guided down into the well from an installation at the surface.
• the perforating lance is preferably arranged at the bottom of the unit, the flushing unit is fitted to the operating string, while the cleaning unit is inserted between the lance and the flushing unit.
• the perforating lance is preferably set up to be released from the other parts of the unit after the explosive charges have been detonated/fired.
• the perforating lance has a number of charges around and along the circumference.
• the explosive charges are preferably formed, in connection with the perforating lance, with different explosive strength in the different sections (A,B,C) of the lance.
• an upper (A) section of the perforating gun/ -perforating lance is formed with greater explosive power in the explosive charges than the rest of the charges.
• the method according to the invention is characterised in that a three-part tool is used, encompassing a lower part comprising a perforating gun (32) to establish said perforations, a middle cleaning part (34) to clean the pipe (20) inside and also an upper flushing section (36) with a flushing fluid to flush loose and dissolve concrete remains in the space between the pipe (20) and the wall of the bore hole
• a three-part tool is used, encompassing a lower part comprising a perforating gun (32) to establish said perforations, a middle cleaning part (34) to clean the pipe (20) inside and also an upper flushing section (36) with a flushing fluid to flush loose and dissolve concrete remains in the space between the pipe (20) and the wall of the bore hole
• the tool (10) is conducted up and down in the perforated area to scrub-clean the inner pipe wall with the help of the cleaning part
• the tool ( 0) is positioned so that the flushing section (36) in the pipe is placed adjoining a set of the perforation holes and such that a number of perforation holes around the circumference lie above the flushing section (36) and form a fluid connection from the annular space between the pipe (20) and the wall of the well and into the annular space (12) between the operating string (30),
• the tool is removed and a material that can be hardened is lowered down to fill a given section of the pipe (20) and the interstitial space between the outer side of the pipe and the wall of the bore hole, whereby the well is plugged when the material hardens.
• Figure 1 shows a tool according to the invention and how it is set up to be installed in a well and operated from a platform on the surface of the ocean.
• Figures 2, 3 and 4 show an enlarged cross-section of the tool installed down in the well.
• Figure 5 shows an enlargement to show details of the perforating lance.
• Figure 1 shows a tool according to the invention 10 fitted to a string or pipe 30 that runs down through a formation 14 from an installation 100, a platform 100 on the ocean or the like.
• the ocean surface is shown by 18 and the sea bed by 16.
• the construction according to the invention can, of course, also be used in connection with an HC exploring installation on land.
• a casing pipe (production pipe) (20) is inserted into the bore hole or the well and this is cemented with concrete 22 to the walls of the bore hole.
• the tool 10 according to the invention is also shown in the figure. It is composed of the three parts, the perforating gun 32, the scrubbing/cleaning unit 34 and the flushing device 36 seen in a direction from below.
• the washing/flushing unit 36 is placed at the top of the combined unit and is connected uppermost in the tool 10 to the lower end of the pipe/line 30. Between the pipe/line 30 and the inside of the casing pipe 20, there is an annular space 12 through which loosened bits of concrete and other impurities can be led during the cleaning/flushing.
• the scrubbing/cleaning unit 34 is fastened immediately below the flushing unit 36 and below this the perforating gun 32 is placed. They consequently form a three part tool with all the functions in one piece.
• Figure 2 shows an enlarged cross-section of the apparatus according to the invention.
• This comprises a cylinder formed column or casing that extends downwards below the scrubbing/cleaning unit and where a number of dedicated explosive charges/explosives 33 are inserted around the periphery and in several rows on the surface, in a previously known manner, i.e. that the blast from the charges are in a horizontal or an inclined direction radially outwards towards the pipe to blow holes in the pipe wall.
• the explosive charges are connected to a trigger unit, for example, via a primer cable which runs from the surface through the pipe 30.
• the charges are made to explode simultaneously and they are facing radially outwards and each one of the charges blasts a hole 35 in the metal of the casing pipe 20 so that a fluid connection is formed radially outwards to the concrete outside the pipe.
• the size of the individual holes can be regulated with the help of the blasting strength of the individual charges 33.
• the scrubbing/cleaning unit 34 can be regulated with the help of the blasting strength of the individual charges 33.
• This cleaning unit comprises brushes, grooves, sharp scraping edges or is grooved 37 on the radially outwardly facing head surface.
• the diameter of the head is adapted to the inner diameter of the pipe 20.
• the brushes 37 that can comprise metal brushes such as a so-called steel brush shall loosen and remove such sharp edges.
• the cleaning brushes can be formed around the circumference so that they can be pulled radially inwards into the tool construction when they are not in use, and be pushed out to make contact with the inner wall of the pipe when the cleaning shall take place.
• a separate mechanism inside the scrubbing part for example, hydraulically operated, can be reset to be pushed out against the wall, or be pulled in from the wall.
• the brushes can be extendable and retractable in a radial direction. They scrape the inner wall only in that the whole apparatus is moved up and down as shown by the arrow P in figure 2.
• the washing/flushing unit 36 The washing/flushing unit 36.
• this flushing unit 36 is placed uppermost in the construction and connected to the above lying pipe and the brushing unit 34 is placed below this and the perforating gun 32 is placed underneath this again at the end of the tool.
• FIG 3 shows a first step in the process.
• the tool 10, with the three parts, is set up for firing the explosive charges.
• a blasting is carried out and holes 35 are made in the pipe.
• the holes 35 run out through the pipe 20 and the explosion also leads to holes being formed more or less in the concrete coat 22 radially outside and which one wants to break up and remove as much as possible.
• the tool is led up and down so that the brushes 37 of the tool 34 can clean the internal surface of the pipe along the holes at the bottom of figure 3.
• Figure 4 shows an important feature of the invention.
• the perforating gun 32 is loosened, with the help of a release mechanism not described further, from the rest of the tool and falls down into the well. After the gun 32 has been dropped, the whole tool is lowered further down so that the flushing unit 36 is aligned with the holes 35.
• the spraying starts in that water/acid is pumped down through the pipe 30 shown by the arrows 42.
• the bottom of the tool i.e. the part which lies above the perforating gun, is sealed with a plate 50 so that the cleaning fluid which is sent down under pressure is forced out into the annular space 38.
• the annular space 38 between the two sealing bellows 36a, 36b is filled with fluid and at a pressure that forces the fluid out through the holes 35 and out into the concrete part one wishes to remove.
• the acid in the water will contribute to dissolving the concrete chemically.
• the water pressure out through the holes will lead to parts of the concrete coat being broken up into smaller and larger pieces. It is shown with the arrows P1 how the fluid flows further upwards and radially back inwards through the
• the lance- formed perforating gun is fitted with sections with different strengths of explosive charges. These sections are marked A, B and C in figure 5.
• the directed charges are designed to give an optimal hole diameter in the casing pipe in the well plus some distance into the existing concrete coat which one wishes to be able to flush loose and flush away or to dissolve chemically with the acid content of the liquid.
• a perforating lance of this type can have a length of 5 to 50 meters and can be divided into the sections A,B and C as mentioned above in the context of explosive power for the individual charges.
• a sealing plug 50 can be placed at the bottom of the pipe and form the bottom of the pipe which shall now be filled with concrete. This can take place in that the bottom of the tool is removed and the concrete is pumped in from the surface and downward through the pipe 30 to fill this and to flow into the space below and outside the tool. The concrete will flow out through the perforations 35 and partially fill the space cleaned of concrete between the outer wall of the pipe and the rock formation in the bore hole. In this way a direct concrete contact between the rock formation 14 will be formed.

Landscapes

• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Geochemistry & Mineralogy (AREA)
• Fluid Mechanics (AREA)
• Environmental & Geological Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Physics & Mathematics (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Chemical & Material Sciences (AREA)
• Earth Drilling (AREA)
• Drilling And Exploitation, And Mining Machines And Methods (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)
• Working Measures On Existing Buildindgs (AREA)
• Processing Of Solid Wastes (AREA)
• Piles And Underground Anchors (AREA)
• Disintegrating Or Milling (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=46602944

Family Applications (1)

Country Status (9)

Cited By (13)

Families Citing this family (12)

Citations (6)

Family Cites Families (13)

• 2011
  • 2011-02-03 NO NO20110190A patent/NO335153B1/no unknown
• 2012
  • 2012-02-03 DK DK12741833.3T patent/DK2670943T3/da active
  • 2012-02-03 EP EP12741833.3A patent/EP2670943B1/en active Active
  • 2012-02-03 RU RU2013138598/03A patent/RU2564427C2/ru active
  • 2012-02-03 US US13/984,339 patent/US20140138078A1/en not_active Abandoned
  • 2012-02-03 CA CA2823816A patent/CA2823816A1/en not_active Abandoned
  • 2012-02-03 WO PCT/NO2012/050016 patent/WO2012105852A1/en active Application Filing
  • 2012-02-03 AU AU2012211550A patent/AU2012211550B2/en active Active
  • 2012-02-03 BR BR112013019782-0A patent/BR112013019782B1/pt active IP Right Grant

Patent Citations (6)

Also Published As

Similar Documents

Legal Events