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
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/10—Sealing or packing boreholes or wells in the borehole
  • E21B33/12—Packers; Plugs
  • E21B33/124—Units with longitudinally-spaced plugs for isolating the intermediate space
  • E21B33/1243—Units with longitudinally-spaced plugs for isolating the intermediate space with inflatable sleeves
• • 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
  • E21B34/00—Valve arrangements for boreholes or wells
  • E21B34/06—Valve arrangements for boreholes or wells in wells
  • E21B34/08—Valve arrangements for boreholes or wells in wells responsive to flow or pressure of the fluid obtained
• • 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
  • E21B43/02—Subsoil filtering
  • E21B43/08—Screens or liners
• • 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
  • E21B43/12—Methods or apparatus for controlling the flow of the obtained fluid to or in wells
• • 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
  • E21B43/14—Obtaining from a multiple-zone well
• • 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
  • E21B43/32—Preventing gas- or water-coning phenomena, i.e. the formation of a conical column of gas or water around wells
• • 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
  • E21B2200/00—Special features related to earth drilling for obtaining oil, gas or water
  • E21B2200/02—Down-hole chokes or valves for variably regulating fluid flow

Definitions

• the present invention relates to a system and method for recompletion of old wells. More specifically the invention relates to a system and a method as disclosed in the preamble of claim 1 and 7, respectively.
• a plurality of autonomous valves or flow control devices are substantially as those described in WO 2008/0048745 Al, belonging to the applicant of the present application.
• WO-A-9208875 describes a horizontal production pipe comprising a plurality of production sections connected by mixing chambers having a larger internal diameter than the production sections.
• the production sections comprise an external slotted liner which can be considered as performing a filtering action.
• the sequence of sections of different diameter creates flow turbulence and prevent the running of work- over tools.
• US 5.435.393 describes a production pipe with a lover drainage pipe divided into sections and with one or more inflow restriction devices which controls the flow of oil or gas from the reservoir into the drainage pipe based on the precalculated loss of 5 friction pressure along the drainage pipe, the precalculated production profile of the reservoir and the precalculated inflow of gas or water. This publication does thus not relate to recompletion of old wells, nor to the use of autonomous flow control devices in said recompletion.
• an inflow control device which is self adjusting or autonomous and can easily be fitted in the wall of a production pipe and which therefore provide for the use of work-over tools.
• the device is designed to "distinguish" between the oil and/or gas and/or water0 and is able to control the flow or inflow of oil or gas, depending on which of these fluids such flow control is required.
• the device as disclosed in WO 2008/0048745 Al is robust, can withstand large forces and high temperatures, needs no energy supply, can withstand sand production, is 5 reliable, but is still simple and very cheap.
• a problem with the prior art is that the well, with or without inflow control devices, has to be abandoned since the well is not able to produce anymore due to gas and/or water breakthrough.
• Short-circuit effects might also appear in low oil zones with zones comprising gas and/or water above or below them.
• the system and method according to the invention seeks to reduce or eliminate the above and other problems or disadvantages by iserting a pipe with a at least one, and preferably a plurality of autonomous valves into an existing well, and thus increase oil recovery with limited investments.
• the invention might thus be regarded as an improvement of an existing stinger solution in which an impervious pipe section having solid walls are arranged on a location in the well in which gas breakthrough previously has been experienced.
• Fig. 1 shows a schematic view of a production pipe with a control device according to WO 2008/0048745 Al
• Fig. 2 a shows, in larger scale, a cross section of the control device according to WO 2008/0048745 Al, b) shows the same device in a top view.
• Fig. 3 is a diagram showing the flow volume through a control device according to the invention vs. the differential pressure in comparison with a fixed inflow device
• Fig. 4 shows the device shown in Fig. 2, but with the indication of different pressure zones influencing the design of the device for different applications.
• Fig. 5 shows a principal sketch of another embodiment of the control device according to WO 2008/0048745 Al
• Fig. 6 shows a principal sketch of a third embodiment of the control device according to WO 2008/0048745 Al
• Fig. 7 shows a principal sketch of a fourth embodiment of the control device according to WO 2008/0048745 Al.
• Fig. 8 shows a principal sketch of a fifth embodiment of WO 2008/0048745 Al where the control device is an integral part of a flow arrangement.
• Fig. 9 shows a principal view of a prior art well intersecting a high permeability zone of a reservoir.
• Fig.10 shows a principal view of the well in fig. 9, which, in accordance with the invention, is recompleted with a new pipe with autonomous valves inserted into the well, causing a substantially uniform inflow into the well.
• Fig. 11a shows a principal view of a lateral well in accordance with the invention, e.g. the well in fig. 10, and
• Fig. l ib shows an enlarged principal view of the part of fig. 11a constricted by a circle.
• Fig. 1 shows, as stated above, a section of a production pipe 1 in which a control device 2, according to WO 2008/0048745 Al is provided.
• the control device 2 is preferably of circular, relatively flat shape and may be provided with external threads 3 (see Fig. 2) to be screwed into a circular hole with corresponding internal threads in the pipe or an injector.
• the device 2 may be adapted to the thickness of the pipe or injector and fit within its outer and inner periphery.
• Fig. 2 a) and b) shows the prior control device 2 of WO 2008/0048745 Al in larger scale.
• the device consists of a first disc-shaped housing body 4 with an outer cylindrical segment 5 and inner cylindrical segment 6 and with a central hole or aperture 10, and a second disc-shaped holder body 7 with an outer cylindrical segment 8, as well as a preferably flat disc or freely movable body 9 provided in an open space 14 formed between the first 4 and second 7 disc-shaped housing and holder bodies.
• the body 9 may for particular applications and adjustments depart from the flat shape and have a partly conical or semicircular shape (for instance towards the aperture 10.)
• the cylindrical segment 8 of the second disc-shaped holder body 7 fits within and protrudes in the opposite direction of the outer cylindrical segment 5 of the first disc-shaped housing body 4 thereby forming a flow path as shown by the arrows 11, where the fluid enters the control device through the central hole or aperture (inlet) 10 and flows towards and radially along the disc 9 before flowing through the annular opening 12 formed between the cylindrical segments 8 and 6 and further out through the annular opening 13 formed between the cylindrical segments 8 and 5.
• the two disc-shaped housing and holder bodies 4, 7 are attached to one another by a screw connection, welding or other means (not further shown in the figures) at a connection area 15 as shown in Fig 2b).
• the present invention exploits the effect of Bernoulli teaching that the sum of static pressure, dynamic pressure and friction is constant along a flow line:
• the pressure difference over the disc 9 can be expressed as follows: ⁇ P over ⁇ [Pover(P t ) Punder(f(p l P2 p 3 ) ⁇ ⁇ ,-, P V
• K is mainly a function of the geometry and less dependent on the Reynolds number.
• the flow area will decrease when the differential pressure increases, such that the volume flow through the control device will not, or nearly not, increase when the pressure drop increases.
• Fig. 3 A comparison between a control device according to the present invention with movable disc and a control device with fixed flow-through opening is shown in Fig. 3, and as can be seen from the figure, the flow-through volume for the present invention is constant above a given differential pressure.
• the control device according to the invention may have two different applications: Using it as inflow control device to reduce inflow of water, or using it to reduce inflow of gas at gas break through situations.
• the different areas and pressure zones as shown in Fig. 4, will have impact on the efficiency and flow through properties of the device. Referring to Fig. 4, the different area/pressure zones may be divided into:
• Pi is the inflow area and pressure respectively.
• the force (PrAi) generated by this pressure will strive to open the control device (move the disc or body 9 upwards).
• P 2 is the area and pressure in the zone where the velocity will be largest and hence represents a dynamic pressure source. The resulting force of the dynamic pressure will strive to close the control device (move the disc or body 9 downwards as the flow velocity increases).
• - A 3 , P 3 is the area and pressure at the outlet. This should be the same as the well pressure (inlet pressure).
• - A 41 P 4 is the area and pressure (stagnation pressure) behind the movable disc or body 9. The stagnation pressure, at position 16 (Fig. 2), creates the pressure and the force behind the body. This will strive to close the control device (move the body downwards).
• Fluids with different viscosities will provide different forces in each zone depending on the design of these zones, hi order to optimize the efficiency and flow through properties of the control device, the design of the areas will be different for different applications, e.g. gas/oil or oil/water flow. Hence, for each application the areas needs to be carefully balanced and optimally designed taking into account the properties and physical conditions (viscosity, temperature, pressure etc.) for each design situation.
• Fig. 5 shows a principal sketch of another embodiment of the control device according to WO 2008/0048745 Al, which is of a more simple design than the version shown in Fig. 2.
• the control device 2 consists, as with the version shown in Fig. 2, of a first disc- shaped housing body 4 with an outer cylindrical segment 5 and with a central hole or aperture 10, and a second disc-shaped holder body 17 attached to the segment 5 of the housing body 4, as well as a preferably flat disc 9 provided in an open space 14 formed between the first and second disc-shaped housing and holder bodies 4, 17.
• Fig. 6 shows a third embodiment according to WO 2008/0048745 Al where the design is the same as with the example shown in Fig. 2, but where a spring element 18, in the form of a spiral or other suitable spring device, is provided on either side of the disc and connects the disc with the holder 7, 22, recess 21 or housing 4.
• the spring element 18 is used to balance and control the inflow area between the disc 9 and the inlet 10, or rather the surrounding edge or seat 19 of the inlet 10.
• the opening between the disc 9 and edge 19 will be larger or smaller, and with a suitable selected spring constant, depending on the inflow and pressure conditions at the selected place where the control device is provided, constant mass flow through the device may be obtained.
• Fig. 7 shows a fourth embodiment according to WO 2008/0048745 Al, where the design is the same as with the example in Fig. 6 above, but where the disc 9 is, on the side facing the inlet opening 10, provided with a thermally responsive device such as bi-metallic element 20.
• the conditions may rapidly change from a situation where only or mostly oil is produced to a situation where only or mostly gas is produced (gas breakthrough or gas coning).
• gas breakthrough or gas coning With for instance a pressure drop of 16 bar from 100 bar the temperature drop would correspond to approximately 20 0 C.
• the disc 9 By providing the disc 9 with a thermally responsive element such as a bi-metallic element as shown in Fig. 7, the disc will bend upwards or be moved upwards by the element 20 abutting the holder shaped body 7 and thereby narrowing the opening between the disc and the inlet 10 or fully closing said inlet.
• control device as shown in Figs. 1 and 2 and 4 - 7 are all related to solutions where the control device as such is a separate unit or device to be provided in conjunction with a fluid flow situation or arrangement such as the wall of a production pipe in connection with the production of oil and gas.
• the control device may, as shown in Fig. 8, be an integral part of the fluid flow arrangement, whereby the movable body 9 may be provided in a recess 21 facing the outlet of an aperture or hole 10 of for instance a wall of a pipe 1 as shown in Fig. 1 instead of being provided in a separate housing body 4.
• the movable body 9 may be held in place in the recess by means of a holder device such as inwardly protruding spikes, a circular ring 22 or the like being connected to the outer opening of the recess by means of screwing, welding or the like.
• a holder device such as inwardly protruding spikes, a circular ring 22 or the like being connected to the outer opening of the recess by means of screwing, welding or the like.
• Fig. 9 shows a principal view of a well 24 intersecting a high permeability zone 25 of a reservoir 26. As indicated by the size of the arrows the inflow into the well 24 is nonuniform, and with a breakthrough in the zone 25 in which substantially all of the inflow occurs.
• Fig.10 shows a principal view of the well in fig. 9, which, in accordance with the invention, is recompleted with a new pipe 27 with autonomous valves (not shown in this figure) inserted into the well, causing a substantially uniform inflow into the well.
• a plurality of constrictors or swell packers 29 are arranged along the well to seal between the inserted pipe 27 and the existing well 24.
• Figs. 11a and 1 Ib respectively show a principal view of a lateral well in accordance with the invention, e.g. the well shown in fig. 10, and an enlarged principal view of the part of fig. 11a constricted by a circle.
• the existing or old well 24 is indicated by dotted lines and the new pipe 27 with autonomous valves 2 (of which only one is shown for clarity) is indicated by solid lines.
• a plurality of autonomous valves 2 are arranged along the length of the inserted pipe 27, and preferably at least one valve 2 in each pipe section defined between two successive constrictors or swell packers 29, in order to create a substantially uniform inflow into the recompleted well 24, 27 and thus an increased oil recovery.
• An embodiment of a method according to the invention preferably comprises the following steps (not necessarily in said order) : Providing an old well 24,
• Providing a new pipe 27 comprising a plurality of autonomous valves 2 arranged along the length of the pipe 27, passing said pipe 27 into said old well 24 for recompleting the old well 24, providing a plurality of swell packers or constrictors 29 along the well to seal between the inserted pipe 27 and the old well 24 and to define a plurality of well sections between two successive constrictors or swell packers 29 in each of which sections at least one autonomous valve 2 is to be located, in order to create a substantially uniform inflow into the recompleted well 24, 27 and thus an increased oil recovery.
• the inserted pipe 27 preferably covers substantially the whole length of the old well 24.
• the pipe 27 just covers a limited length to be arranged at a very distinct location in the well 24 in which breakthrough is to be prevented, i.e. a distinct fraction in the formation or reservoir 26 intersectied by the well 24. This location will then be isolated by providing one constrictor or swell packer 29 on each side of said fraction, and with just one autonomous valve 2 arranged in such a single isolated section of the well.
• the autonomous valves 2 preferably are those described in WO 2008/0048745 Al and above, but any type of autonomous valve (e.g. electronically operated) is conceivable within the context of the invention.

Landscapes

• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• Physics & Mathematics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Pipe Accessories (AREA)
• Transplanting Machines (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)
• Control Of Fluid Pressure (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (2)

Family

ID=41136044

Family Applications (1)

Country Status (9)

Cited By (2)

Families Citing this family (10)

Family Cites Families (13)

• 2009
  • 2009-04-01 BR BRPI0909459A patent/BRPI0909459A2/pt not_active IP Right Cessation
  • 2009-04-01 MX MX2010010623A patent/MX2010010623A/es unknown
  • 2009-04-01 CN CN200980111476XA patent/CN101981270A/zh active Pending
  • 2009-04-01 WO PCT/NO2009/000124 patent/WO2009123472A2/en not_active Ceased
  • 2009-04-01 EA EA201071158A patent/EA018335B1/ru not_active IP Right Cessation
  • 2009-04-01 AU AU2009232495A patent/AU2009232495A1/en not_active Abandoned
  • 2009-04-01 CA CA2718832A patent/CA2718832A1/en not_active Abandoned
  • 2009-04-01 US US12/935,958 patent/US20110056700A1/en not_active Abandoned
  • 2009-04-01 EP EP09726962A patent/EP2271822A2/en not_active Withdrawn

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