CA2629607A1 - A device for a borehole arrangement - Google Patents
A device for a borehole arrangement Download PDFInfo
- Publication number
- CA2629607A1 CA2629607A1 CA002629607A CA2629607A CA2629607A1 CA 2629607 A1 CA2629607 A1 CA 2629607A1 CA 002629607 A CA002629607 A CA 002629607A CA 2629607 A CA2629607 A CA 2629607A CA 2629607 A1 CA2629607 A1 CA 2629607A1
- Authority
- CA
- Canada
- Prior art keywords
- casing
- terized
- charac
- accordance
- fluid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000005553 drilling Methods 0.000 claims abstract description 31
- 239000012530 fluid Substances 0.000 claims description 79
- 238000009434 installation Methods 0.000 claims description 20
- 238000012544 monitoring process Methods 0.000 claims description 5
- 238000012546 transfer Methods 0.000 claims description 3
- 230000015572 biosynthetic process Effects 0.000 description 6
- 238000007789 sealing Methods 0.000 description 6
- 238000005520 cutting process Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000004323 axial length Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
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
- E21B7/00—Special methods or apparatus for drilling
- E21B7/20—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes
- E21B7/208—Driving or forcing casings or pipes into boreholes, e.g. sinking; Simultaneously drilling and casing boreholes using down-hole drives
-
- 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
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/20—Flexible or articulated drilling pipes, e.g. flexible or articulated rods, pipes or cables
-
- 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
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/20—Flexible or articulated drilling pipes, e.g. flexible or articulated rods, pipes or cables
- E21B17/203—Flexible or articulated drilling pipes, e.g. flexible or articulated rods, pipes or cables with plural fluid passages
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Mechanical Engineering (AREA)
- Earth Drilling (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
A device for a borehole arrangement, in which a casing (11) for a borehole (3) is formed of at least one casing section (11a) , and in which there is placed at a downhole end portion (11b) of the casing (11) at least one downhole tool (21), for example a drilling tool, characterized in that the casing (11) is provided with two or more pipe bores (12, 13a, 13b), each separately extending continuously through a substantial part of the length of the casing (11) and being separated in a fluid-tight manner from adjacent pipe bores (12, 13b, 13a) and from an external annulus (14) defined by the external mantle surface of the pipe (11) and a borehole wall (5a).
Description
A DEVICE FOR A BOREHOLE ARRANGEMENT
The invention relates to a multibore casing for a borehole, in particular for an exploration or production well for hydrocarbons of the type of well that exhibits a long horizontal extent, and in particular a well which is formed by there being placed in the open well bore an automotive downhole tractor provided with means for drilling.
From the state of the art is known the use of casing with a stepped diameter and the conveyance of fluids (drilling fluid etc.) in a pipe string, for example a drill string or coiled tubing, in the centre bore of the casing and return of the fluids in an annulus between the casing and the pipe string placed internally in the casing, the drilling tool being moved forward by the pipe string being moved down and outwards. When new sections of casing are being placed into the open borehole, the drill string must first be pulled up.
When the extent of the borehole is several kilometres, it stands to reason that each tripping out and tripping in of the drill string is both time-consuming and costly. A long borehole will also exhibit a very small diameter at its outer end due to the constantly stepped diameter of the casing sections. This limits the possibility of using complex downhole tools in a completion string.
When the borehole diameter decreases, the size of the annulus between the casing and drill string will also decrease. This affects the flow rate of, for example, the drilling fluid which is carrying cuttings to the surface, as the specific annulus volume increases from the lower/outer end of the borehole towards the earth surface/seabed. Thereby the flow rate decreases, and this may lead to the sedimentation of cuttings with the risk of the annulus passage clogging up.
From Eventure Global Technology, among others, it is known to use a borehole with the same diameter throughout, the borehole being cased, as the drilling proceeds, with expandable casings in the lower end portion of the borehole.
The drawbacks of this technique are high costs and also uncertainty about the mechanical strength and sealing against leakage, in the pipe connections among other things.
The invention has as its object to remedy or reduce at least one of the drawbacks of the prior art.
The object is achieved through features specified in the description below and in the claims that follow.
The invention relates to a technique for drilling and constructing production wells for hydrocarbons, in particular long, horizontal wells. In a first aspect of the invention there are used double-walled casings with several passages in the annulus between the two pipe walls. The passages are arranged for conveying fluids and/or extending cables for the transfer of signals or power, for example. The casing preferably exhibits the same diameter throughout the length of the well.
Alternatively, the casings may include channels placed on the external side of the pipes or integrated into the pipe wall.
The casing may advantageously include one or more channels on the outside of the pipe for shielding cables for the conveyance of electrical power or control and/or monitoring signals between a surface installation and downhole installations along the casing or at the end portion of the casing.
Another aspect of the invention relates to remote-controlled packers that are placed on the periphery of the casing, preferably one for each pipe section, the packer being arranged to be releasably set in a fluid-sealing manner against the wall of the borehole. The packer includes means for controlled fluid flow at least in the direction from the downhole end portion of the casing. In this aspect is achieved that a fluid, for example drilling mud, of a specific weight etc. adjusted to the properties of the adjacent formation, may be kept enclosed in the part of the annulus outside the casing defined between two packers. When the casing is moved down the borehole and drilling mud is supplied to said annulus at the downhole end portion of the casing, said enclosed fluid is pushed through the open fluid passage of its respective packer above into the section of the annulus above. Thereby the adjusted fluid maintains its position relative to the surrounding formation while the casing is moved down. When the moving of the casing has been stopped, the packers are set again against the borehole wall and the means in the packers for fluid flow are possibly closed by remote control. Thereby the risk of a formation being affected by a fluid with properties having an adverse effect on the formation is reduced.
Advantageously, the packers may include sensors for monitoring the borehole, formation and/or casing.
Another aspect of the invention relates to a remote-controlled downhole tool, for example a downhole tractor, which is placed in the open, uncased well bore adjacent to and in front of (below) the downhole end portion of the casing, the downhole tool being provided at least with means which are arranged to drill in the well formation. This enables well drilling while the casing is moved forward behind the downhole tool by means of gravity and possibly by the downhole tool being mechanically connected to a downhole end portion of the casing, so that the casing can be pulled forward by means of the downhole tractor.
The downhole tool is in fluid-communicating and signal-communicating connection with a surface installation, for example a drilling rig, by fluid, electric power, control and monitoring signals being conveyed through the appropriate lines at the wall of the casing and also suitable flexible lines connecting the downhole end portion of the casing and the downhole tool.
One packer is placed at the downhole end of the casing, thereby defining the open well bore to include a portion extending only from the end of the borehole to the downhole end of the casing. Thereby only a short borehole portion is the subject of hole cleaning by flushing with drilling mud, for example.
The invention relates in particular to a device for a borehole arrangement, in which a casing for a borehole is formed of at least one casing section, and in which there is placed at the downhole end portion of the casing at least one downhole tool, for example a drilling tool, characterized in that the casing is provided with two or more pipe bores, each separately extending continuously through a substantial part of the length of the casing and being separated in a fluid-tight manner from adjacent pipe bores and from an external annulus defined by the external mantle surface of the pipe and the wall of the borehole.
At least one pipe bore is preferably arranged in the wall of the casing or on or at the external mantle surface of the casing.
Advantageously, the casing includes one or more channels extending in the axial direction on the external mantle surface of the casing and being arranged to receive one or more lines for fluid transport or for the transfer of control and/or monitoring signals between a surface installation and downhole installations placed along the casing or at the downhole end portion of the casing.
The casing is preferably provided with one or more annular packers surrounding the casing and being arranged to selectively and fluid-communicatingly define a portion of the external annulus by the packer being releasably set against the wall of the borehole.
Alternatively, a plurality of the packers are placed on the casing adjacent to the downhole end portion of the casing, the packers including means for selective release and fixing relative to the external mantle surface of the casing and selective fixing against the borehole wall.
Preferably, the packers are provided with one or more closable packer fluid passages.
The packer fluid passages are advantageously arranged to close to fluid passage in a chosen direction and, at the same time, to stay open to fluid passage in the opposite direction.
The packer fluid passages are advantageously formed as check valves.
Preferably, the packer is provided with means for controlled fixing and release of the packer relative to the borehole wall.
Preferably, an end cover is placed in a fluid-sealing manner on the downhole end portion of the casing.
Preferably, the end cover is provided with one or more closable end cover fluid passages.
Advantageously, the end cover is provided with one or more closable passages for downhole equipment.
Advantageously, the end cover fluid passages are arranged to close to fluid passage in a chosen direction and at the same time stay open to fluid passage in the opposite direction.
Alternatively, the fluid passages are formed as check valves.
Advantageously, the end cover is provided with one or more fluid-sealingly closable passages for downhole equipment.
In one aspect the downhole tool is a downhole tractor which is arranged to move in an open, uncased portion of the borehole at the downhole end portion of the casing and to carry means for working the borehole.
Preferably, the downhole tool is connected in a fluid-communicating manner to at least one of the pipe bores of the casing for the circulation of one or more fluids between a surface installation and the downhole tool with return to the surface installation, possibly between the surface installation, the downhole tool and the open borehole with return to the surface installation.
Advantageously, the downhole tool is mechanically connected to the downhole end portion of the casing and is arranged to pull the casing into the open portion of the borehole.
Advantageously, the downhole end portion of the casing is mechanically connected to a pulling device on the downhole tool.
The pulling device is preferably a winch.
In one aspect of the invention at least one of said two or more bores is preferably provided with selectively closable openings in said downhole end portion of the casing.
In what follows, is described a non-limiting example of a preferred embodiment which is visualized in the accompanying drawings, in which:
Figure 1 shows a principle sketch of a cut-through hydrocarbon well with a derrick and casing, downhole tool and means for the circulation of a drilling fluid connected to the casing;
Figure la shows, on a larger scale, a longitudinal section Ia-Ia of figure lb through a downhole end portion of the casing with an end cover and a casing portion at an annulus packer;
Figure lb shows a cross-section Ib-Ib of figure la of a downhole end portion of the casing at the end cover;
Figure 2 shows on the same scale as figure 1 a section of the installation with the casing in a position prepared for extension, the means for the circulation of the drilling fluid being disconnected;
Figure 3 shows a section of the installation, in which the casing has been extended;
Figure 4 shows a section of the installation, in which the casing has been pulled partially into the well bore; and Figure 5 shows a section of the installation, in which the means for the circulation of a drilling fluid have been reconnected and the casing has been pulled into the well bore.
Reference is made primarily to the figures 1, la and lb. A
derrick 1 is located at a borehole 3 which extends through an underground structure 5 and up to an open, that is to say an uncased, downhole end portion 3a, the borehole 3 forming a borehole wall 5a. A substantial part of the borehole 3 is provided with a casing 11 including a centre bore 12 and a pipe wall 13. The pipe wall 13 is provided with several pipe bores 13a, 13b extending through it, each separated in a fluid-tight manner from the other pipe bores 12, 13a, 13b and from an annulus 14 formed between the casing 11 and the borehole wall 5a.
The casing 11 is provided with several annular packers 15, 15a surrounding the casing 11 and being arranged to bear sealingly on the borehole wall 5a, one pair of adjacent packers 15, 15' defining a portion of the annulus 14 relative to adjacent annulus portions formed by other packers 15, 15'.
The packer 15 is provided with means (not shown) for controlled fixing and release of the packer 15 relative to the borehole wall 5a. The packer 15 is also provided with packer fluid passages 15a (see figure la) which are arranged to close to fluid passage in a chosen direction and at the same time stay open to fluid passage in the opposite direction. The direction of flow of fluid through the packer fluid passage 15a is preferably from the downhole end portion 11b of the casing ii towards the derrick 1. The packer fluid passage 15a is typically formed as a check valve which can be closed.
A downhole end portion 11a of the casing 11 is provided with a fluid-sealing end cover 11b. The end cover 11b is provided with a fluid passage 11c, 11d corresponding to the pipe bores 13a, 13b. A first end cover fluid passage 11c is provided with means for fluid communication between the pipe bore 13a and a downhole tool 21 via a flexible line 22. A second end cover fluid passage 11d is in fluid communication with the open end portion 3a of the borehole 3 and with the pipe bore 13b. The end cover fluid passages 11c, 11d are provided with means 11e, 11f which are arranged for selective opening and closing to fluid flow, for example by means of remote control.
The downhole tool 21 is typically a downhole tractor of a type known per se.
The end cover 11b is also provided with a peripherally placed, annular end cover packer 11g which is provided with means (not shown) for controlled fixing and release of the end cover packer 11g relative to the borehole wall 5a. In a manner corresponding to that of the packer 15, the end cover packer 11g is provided with a packer fluid passage 15a which is arranged to close to fluid passage in a chosen direction and at the same time stay open to fluid passage in the opposite direction. The direction of flow of fluid through the packer fluid passage 15a is preferably from the dow.nhole end portion 11b of the casing 11 towards the derrick 1.
Externally, the casing 11 is also provided with a recessed channel 16 (se figure lb) extending in the entire axial length of the casing 11. The channel 16 is arranged for receiving and retaining cables 17, for example, for conveying measuring data, control signals etc. The packers 15 and end cover 11b are provided with fluid-sealing cable passages complementary to the channel 16.
The downhole tool 21 has the form of a downhole tractor which is provided with propulsion means 23a which are arranged to be selectively engaged with the borehole wall 5a. Via the flexible line 22, the first end cover fluid passage lic of the end cover 11b, the pipe bore 13a of the casing 11 and a flexible pump hose 31a, the downhole tool 21 is connected in a fluid-communicating manner to a pump 31 with associated fluid reservoir (not shown) placed at the surface installation. Via the cables 17 the downhole tool 21 is also connected to a control system 33 placed on or above the ground surface and arranged to store and interpret measuring data, generate control signals etc.
The downhole tool 21 is typically provided with means for working the borehole 3, for example a drill bit 24.
The downhole tool 21 is also provided with a winch 23. A wire 23c of tensile strength is extended between the winch 23 and the end portion 11a of the casing 11 and releasably attached thereto. By means of a drive powered by an available energy source and a remote control, the winch is arranged to wind or unwind the wire 23c.
The downhole tool 21 is also arranged to receive fluid under pressure through the flexible line 22 for the movement of the propulsion means 23a, operation of the winch 23 and drill bit 24. The downhole tool 21 includes fluid outlet openings (not shown) which are of such arrangement that out-flowing fluid may flush the open borehole end portion 3a before the fluid flows through the second end cover fluid passage 11d, through the second pipe bore 13b and via a flexible tank line 32a into a fluid collecting tank 32. The fluid is typically drilling mud which is arranged to maintain pressure control in the well, lubricate the downhole tool 21 and carry off cuttings from the borehole 3.
Arrows indicate the ordinary direction of flow of drilling mud during drilling.
Figures 2-5 show different stages in the extension of the casing 11 by a casing section 11a being joined to the casing 11 at the upper end of the casing 11.
By the use of the device according to the invention a borehole is formed in the ordinary manner by, for example, a casing being driven down into loose masses located above the structure to be drilled, so that a cased hole is formed down to the bedrock 5. After that, an uncased borehole 3 is formed through the bedrock 5 as far as feasible without the borehole wall 5a having to be secured with casing, appropriate drilling equipment being used, for example an ordinary drill string with a rotating drill bit and drilling mud conveyance through the drill string to the drill bit and return in the annulus between the drill string and the borehole wall.
When the drilling approaches a structure which requires casing of the borehole 3, the drilling equipment is removed.
The downhole tool 21 is joined to a first casing section 11a, which is provided with an end cover 11b at its downhole end portion 11a, by means of the flexible line 22 and the wire 23c. By means of the cables 17 the downhole tractor 21 is connected to the control system 33 for the storing and interpretation of measured data, generation of control signals etc.
The downhole tool 21 and the first casing section 11a are moved down into the borehole 3. The casing 11 is extended with new sections 11a as required, the sections 11a being joined together in a fluid-sealing manner, so that continuous pipe bores 13a, 13b and channel 16 extend over the entire length of the joined casing 11, and the cables 17 extend along the casing 11 as the cables 17 are laid and fixed within the channel 16.
When the downhole tool 21 has reached the bottom of the predrilled borehole 3 and the borehole 3 is cased, preparations are made for drilling and moving forward casing according to the invention. The packers 11g, 15 are set against the borehole wall 5a. Weight fluid with the prescribed properties is pumped through one or more pipe bores 12, 13a, 13b down to the uncased downhole end portion 3a and up into the annulus 14 through the packer fluid passages 15a.
The downhole tool 21 is set into operation as drilling fluid is pumped by means of the pump 31 through the pipe bore 13a to the downhole tractor 21 and the propulsion means 23a and drill bit 24, these being activated by means of the control system 33. As the open borehole portion 3a is extended, it is flushed with the drilling mud flowing out of the fluid outlets (not shown) of the downhole tool 21. The drilling mud together with the cuttings from the drilling flows via the pipe bore 13b back to the surface where it is collected in the fluid collecting tank 32, in which it undergoes treatment in a manner known per se. When the downhole tool 21 moves forward during the drilling, the wire 23c is preferably pulled out by the winch 23, so that the downhole tractor does not exert pull on the casing 11.
When the open borehole portion 3a has got a suitable length, the downhole tool is fixed against the borehole wall 5a in a manner known per se by means of the propulsion means 23a. The packers 11g, 15 are released from the borehole wall 5a, weight fluid is pumped down the open borehole portion 3a and the winch 23 is started. The casing 11 is thereby pulled into the borehole 3 as weight fluid is flowing through the packer fluid passages 15a into the annulus 14. The packer fluid passages 15a being arranged for fluid flow only in the direction away from the open downhole borehole portion 3a, the weight fluid will, to a substantial degree, maintain its initial position relative to the surrounding rock structure 5. Thereby, movement of the casing 11 according to the invention will maintain a prescribed placement of weight fluid with properties adjusted to the surrounding structures, the prevailing pressure conditions etc. When the casing 11 has been pulled forward into the desired position, either by having reached a desired distance from the downhole tractor 21, or by a new casing section 11a having to be joined to the upper end of the casing 11, the packers llg, 15 are set again against the borehole wall 5a.
When a new casing section 11a is to be joined to the casing 11, the hoses 31a, 32a are disconnected, a fluid-tight joining is carried out and the join of the casing 11 is tested in the prescribed manner. After the hoses 31a, 32a have been reconnected, the drilling operation and forward movement of the casing 11 are then repeated, as it is described above, until the desired length of the borehole 3 has been reached and the borehole has been cased.
The end cover 11b may advantageously be provided with a passage (not shown) for bottom-hole tools, the passage being fluid-sealingly closable by means of, for example, remote control from the control system 33. Thereby, after release from the end cover 11, the downhole tractor 21 can be retrieved from the borehole in a manner known per se, and another bottom-hole tool may be moved into the open end portion 3a of the borehole 3.
In an alternative embodiment all or a plurality of the packers 15 may be placed on the casing 11 adjacent to the downhole end portion 11a of the casing 11 when the insertion of the casing 15 into the borehole 3 starts. The packers 15 are provided with means (not shown) enabling selective release and fixing of the packers 15 relative to the external mantle surface of the casing 11 and selective fixing of the packer 15 to the borehole wall 5a during the moving forward of the,casing within the borehole 3. Thereby the packers 15 may be set where there is a need for them according to analyses of the borehole 3.
The invention relates to a multibore casing for a borehole, in particular for an exploration or production well for hydrocarbons of the type of well that exhibits a long horizontal extent, and in particular a well which is formed by there being placed in the open well bore an automotive downhole tractor provided with means for drilling.
From the state of the art is known the use of casing with a stepped diameter and the conveyance of fluids (drilling fluid etc.) in a pipe string, for example a drill string or coiled tubing, in the centre bore of the casing and return of the fluids in an annulus between the casing and the pipe string placed internally in the casing, the drilling tool being moved forward by the pipe string being moved down and outwards. When new sections of casing are being placed into the open borehole, the drill string must first be pulled up.
When the extent of the borehole is several kilometres, it stands to reason that each tripping out and tripping in of the drill string is both time-consuming and costly. A long borehole will also exhibit a very small diameter at its outer end due to the constantly stepped diameter of the casing sections. This limits the possibility of using complex downhole tools in a completion string.
When the borehole diameter decreases, the size of the annulus between the casing and drill string will also decrease. This affects the flow rate of, for example, the drilling fluid which is carrying cuttings to the surface, as the specific annulus volume increases from the lower/outer end of the borehole towards the earth surface/seabed. Thereby the flow rate decreases, and this may lead to the sedimentation of cuttings with the risk of the annulus passage clogging up.
From Eventure Global Technology, among others, it is known to use a borehole with the same diameter throughout, the borehole being cased, as the drilling proceeds, with expandable casings in the lower end portion of the borehole.
The drawbacks of this technique are high costs and also uncertainty about the mechanical strength and sealing against leakage, in the pipe connections among other things.
The invention has as its object to remedy or reduce at least one of the drawbacks of the prior art.
The object is achieved through features specified in the description below and in the claims that follow.
The invention relates to a technique for drilling and constructing production wells for hydrocarbons, in particular long, horizontal wells. In a first aspect of the invention there are used double-walled casings with several passages in the annulus between the two pipe walls. The passages are arranged for conveying fluids and/or extending cables for the transfer of signals or power, for example. The casing preferably exhibits the same diameter throughout the length of the well.
Alternatively, the casings may include channels placed on the external side of the pipes or integrated into the pipe wall.
The casing may advantageously include one or more channels on the outside of the pipe for shielding cables for the conveyance of electrical power or control and/or monitoring signals between a surface installation and downhole installations along the casing or at the end portion of the casing.
Another aspect of the invention relates to remote-controlled packers that are placed on the periphery of the casing, preferably one for each pipe section, the packer being arranged to be releasably set in a fluid-sealing manner against the wall of the borehole. The packer includes means for controlled fluid flow at least in the direction from the downhole end portion of the casing. In this aspect is achieved that a fluid, for example drilling mud, of a specific weight etc. adjusted to the properties of the adjacent formation, may be kept enclosed in the part of the annulus outside the casing defined between two packers. When the casing is moved down the borehole and drilling mud is supplied to said annulus at the downhole end portion of the casing, said enclosed fluid is pushed through the open fluid passage of its respective packer above into the section of the annulus above. Thereby the adjusted fluid maintains its position relative to the surrounding formation while the casing is moved down. When the moving of the casing has been stopped, the packers are set again against the borehole wall and the means in the packers for fluid flow are possibly closed by remote control. Thereby the risk of a formation being affected by a fluid with properties having an adverse effect on the formation is reduced.
Advantageously, the packers may include sensors for monitoring the borehole, formation and/or casing.
Another aspect of the invention relates to a remote-controlled downhole tool, for example a downhole tractor, which is placed in the open, uncased well bore adjacent to and in front of (below) the downhole end portion of the casing, the downhole tool being provided at least with means which are arranged to drill in the well formation. This enables well drilling while the casing is moved forward behind the downhole tool by means of gravity and possibly by the downhole tool being mechanically connected to a downhole end portion of the casing, so that the casing can be pulled forward by means of the downhole tractor.
The downhole tool is in fluid-communicating and signal-communicating connection with a surface installation, for example a drilling rig, by fluid, electric power, control and monitoring signals being conveyed through the appropriate lines at the wall of the casing and also suitable flexible lines connecting the downhole end portion of the casing and the downhole tool.
One packer is placed at the downhole end of the casing, thereby defining the open well bore to include a portion extending only from the end of the borehole to the downhole end of the casing. Thereby only a short borehole portion is the subject of hole cleaning by flushing with drilling mud, for example.
The invention relates in particular to a device for a borehole arrangement, in which a casing for a borehole is formed of at least one casing section, and in which there is placed at the downhole end portion of the casing at least one downhole tool, for example a drilling tool, characterized in that the casing is provided with two or more pipe bores, each separately extending continuously through a substantial part of the length of the casing and being separated in a fluid-tight manner from adjacent pipe bores and from an external annulus defined by the external mantle surface of the pipe and the wall of the borehole.
At least one pipe bore is preferably arranged in the wall of the casing or on or at the external mantle surface of the casing.
Advantageously, the casing includes one or more channels extending in the axial direction on the external mantle surface of the casing and being arranged to receive one or more lines for fluid transport or for the transfer of control and/or monitoring signals between a surface installation and downhole installations placed along the casing or at the downhole end portion of the casing.
The casing is preferably provided with one or more annular packers surrounding the casing and being arranged to selectively and fluid-communicatingly define a portion of the external annulus by the packer being releasably set against the wall of the borehole.
Alternatively, a plurality of the packers are placed on the casing adjacent to the downhole end portion of the casing, the packers including means for selective release and fixing relative to the external mantle surface of the casing and selective fixing against the borehole wall.
Preferably, the packers are provided with one or more closable packer fluid passages.
The packer fluid passages are advantageously arranged to close to fluid passage in a chosen direction and, at the same time, to stay open to fluid passage in the opposite direction.
The packer fluid passages are advantageously formed as check valves.
Preferably, the packer is provided with means for controlled fixing and release of the packer relative to the borehole wall.
Preferably, an end cover is placed in a fluid-sealing manner on the downhole end portion of the casing.
Preferably, the end cover is provided with one or more closable end cover fluid passages.
Advantageously, the end cover is provided with one or more closable passages for downhole equipment.
Advantageously, the end cover fluid passages are arranged to close to fluid passage in a chosen direction and at the same time stay open to fluid passage in the opposite direction.
Alternatively, the fluid passages are formed as check valves.
Advantageously, the end cover is provided with one or more fluid-sealingly closable passages for downhole equipment.
In one aspect the downhole tool is a downhole tractor which is arranged to move in an open, uncased portion of the borehole at the downhole end portion of the casing and to carry means for working the borehole.
Preferably, the downhole tool is connected in a fluid-communicating manner to at least one of the pipe bores of the casing for the circulation of one or more fluids between a surface installation and the downhole tool with return to the surface installation, possibly between the surface installation, the downhole tool and the open borehole with return to the surface installation.
Advantageously, the downhole tool is mechanically connected to the downhole end portion of the casing and is arranged to pull the casing into the open portion of the borehole.
Advantageously, the downhole end portion of the casing is mechanically connected to a pulling device on the downhole tool.
The pulling device is preferably a winch.
In one aspect of the invention at least one of said two or more bores is preferably provided with selectively closable openings in said downhole end portion of the casing.
In what follows, is described a non-limiting example of a preferred embodiment which is visualized in the accompanying drawings, in which:
Figure 1 shows a principle sketch of a cut-through hydrocarbon well with a derrick and casing, downhole tool and means for the circulation of a drilling fluid connected to the casing;
Figure la shows, on a larger scale, a longitudinal section Ia-Ia of figure lb through a downhole end portion of the casing with an end cover and a casing portion at an annulus packer;
Figure lb shows a cross-section Ib-Ib of figure la of a downhole end portion of the casing at the end cover;
Figure 2 shows on the same scale as figure 1 a section of the installation with the casing in a position prepared for extension, the means for the circulation of the drilling fluid being disconnected;
Figure 3 shows a section of the installation, in which the casing has been extended;
Figure 4 shows a section of the installation, in which the casing has been pulled partially into the well bore; and Figure 5 shows a section of the installation, in which the means for the circulation of a drilling fluid have been reconnected and the casing has been pulled into the well bore.
Reference is made primarily to the figures 1, la and lb. A
derrick 1 is located at a borehole 3 which extends through an underground structure 5 and up to an open, that is to say an uncased, downhole end portion 3a, the borehole 3 forming a borehole wall 5a. A substantial part of the borehole 3 is provided with a casing 11 including a centre bore 12 and a pipe wall 13. The pipe wall 13 is provided with several pipe bores 13a, 13b extending through it, each separated in a fluid-tight manner from the other pipe bores 12, 13a, 13b and from an annulus 14 formed between the casing 11 and the borehole wall 5a.
The casing 11 is provided with several annular packers 15, 15a surrounding the casing 11 and being arranged to bear sealingly on the borehole wall 5a, one pair of adjacent packers 15, 15' defining a portion of the annulus 14 relative to adjacent annulus portions formed by other packers 15, 15'.
The packer 15 is provided with means (not shown) for controlled fixing and release of the packer 15 relative to the borehole wall 5a. The packer 15 is also provided with packer fluid passages 15a (see figure la) which are arranged to close to fluid passage in a chosen direction and at the same time stay open to fluid passage in the opposite direction. The direction of flow of fluid through the packer fluid passage 15a is preferably from the downhole end portion 11b of the casing ii towards the derrick 1. The packer fluid passage 15a is typically formed as a check valve which can be closed.
A downhole end portion 11a of the casing 11 is provided with a fluid-sealing end cover 11b. The end cover 11b is provided with a fluid passage 11c, 11d corresponding to the pipe bores 13a, 13b. A first end cover fluid passage 11c is provided with means for fluid communication between the pipe bore 13a and a downhole tool 21 via a flexible line 22. A second end cover fluid passage 11d is in fluid communication with the open end portion 3a of the borehole 3 and with the pipe bore 13b. The end cover fluid passages 11c, 11d are provided with means 11e, 11f which are arranged for selective opening and closing to fluid flow, for example by means of remote control.
The downhole tool 21 is typically a downhole tractor of a type known per se.
The end cover 11b is also provided with a peripherally placed, annular end cover packer 11g which is provided with means (not shown) for controlled fixing and release of the end cover packer 11g relative to the borehole wall 5a. In a manner corresponding to that of the packer 15, the end cover packer 11g is provided with a packer fluid passage 15a which is arranged to close to fluid passage in a chosen direction and at the same time stay open to fluid passage in the opposite direction. The direction of flow of fluid through the packer fluid passage 15a is preferably from the dow.nhole end portion 11b of the casing 11 towards the derrick 1.
Externally, the casing 11 is also provided with a recessed channel 16 (se figure lb) extending in the entire axial length of the casing 11. The channel 16 is arranged for receiving and retaining cables 17, for example, for conveying measuring data, control signals etc. The packers 15 and end cover 11b are provided with fluid-sealing cable passages complementary to the channel 16.
The downhole tool 21 has the form of a downhole tractor which is provided with propulsion means 23a which are arranged to be selectively engaged with the borehole wall 5a. Via the flexible line 22, the first end cover fluid passage lic of the end cover 11b, the pipe bore 13a of the casing 11 and a flexible pump hose 31a, the downhole tool 21 is connected in a fluid-communicating manner to a pump 31 with associated fluid reservoir (not shown) placed at the surface installation. Via the cables 17 the downhole tool 21 is also connected to a control system 33 placed on or above the ground surface and arranged to store and interpret measuring data, generate control signals etc.
The downhole tool 21 is typically provided with means for working the borehole 3, for example a drill bit 24.
The downhole tool 21 is also provided with a winch 23. A wire 23c of tensile strength is extended between the winch 23 and the end portion 11a of the casing 11 and releasably attached thereto. By means of a drive powered by an available energy source and a remote control, the winch is arranged to wind or unwind the wire 23c.
The downhole tool 21 is also arranged to receive fluid under pressure through the flexible line 22 for the movement of the propulsion means 23a, operation of the winch 23 and drill bit 24. The downhole tool 21 includes fluid outlet openings (not shown) which are of such arrangement that out-flowing fluid may flush the open borehole end portion 3a before the fluid flows through the second end cover fluid passage 11d, through the second pipe bore 13b and via a flexible tank line 32a into a fluid collecting tank 32. The fluid is typically drilling mud which is arranged to maintain pressure control in the well, lubricate the downhole tool 21 and carry off cuttings from the borehole 3.
Arrows indicate the ordinary direction of flow of drilling mud during drilling.
Figures 2-5 show different stages in the extension of the casing 11 by a casing section 11a being joined to the casing 11 at the upper end of the casing 11.
By the use of the device according to the invention a borehole is formed in the ordinary manner by, for example, a casing being driven down into loose masses located above the structure to be drilled, so that a cased hole is formed down to the bedrock 5. After that, an uncased borehole 3 is formed through the bedrock 5 as far as feasible without the borehole wall 5a having to be secured with casing, appropriate drilling equipment being used, for example an ordinary drill string with a rotating drill bit and drilling mud conveyance through the drill string to the drill bit and return in the annulus between the drill string and the borehole wall.
When the drilling approaches a structure which requires casing of the borehole 3, the drilling equipment is removed.
The downhole tool 21 is joined to a first casing section 11a, which is provided with an end cover 11b at its downhole end portion 11a, by means of the flexible line 22 and the wire 23c. By means of the cables 17 the downhole tractor 21 is connected to the control system 33 for the storing and interpretation of measured data, generation of control signals etc.
The downhole tool 21 and the first casing section 11a are moved down into the borehole 3. The casing 11 is extended with new sections 11a as required, the sections 11a being joined together in a fluid-sealing manner, so that continuous pipe bores 13a, 13b and channel 16 extend over the entire length of the joined casing 11, and the cables 17 extend along the casing 11 as the cables 17 are laid and fixed within the channel 16.
When the downhole tool 21 has reached the bottom of the predrilled borehole 3 and the borehole 3 is cased, preparations are made for drilling and moving forward casing according to the invention. The packers 11g, 15 are set against the borehole wall 5a. Weight fluid with the prescribed properties is pumped through one or more pipe bores 12, 13a, 13b down to the uncased downhole end portion 3a and up into the annulus 14 through the packer fluid passages 15a.
The downhole tool 21 is set into operation as drilling fluid is pumped by means of the pump 31 through the pipe bore 13a to the downhole tractor 21 and the propulsion means 23a and drill bit 24, these being activated by means of the control system 33. As the open borehole portion 3a is extended, it is flushed with the drilling mud flowing out of the fluid outlets (not shown) of the downhole tool 21. The drilling mud together with the cuttings from the drilling flows via the pipe bore 13b back to the surface where it is collected in the fluid collecting tank 32, in which it undergoes treatment in a manner known per se. When the downhole tool 21 moves forward during the drilling, the wire 23c is preferably pulled out by the winch 23, so that the downhole tractor does not exert pull on the casing 11.
When the open borehole portion 3a has got a suitable length, the downhole tool is fixed against the borehole wall 5a in a manner known per se by means of the propulsion means 23a. The packers 11g, 15 are released from the borehole wall 5a, weight fluid is pumped down the open borehole portion 3a and the winch 23 is started. The casing 11 is thereby pulled into the borehole 3 as weight fluid is flowing through the packer fluid passages 15a into the annulus 14. The packer fluid passages 15a being arranged for fluid flow only in the direction away from the open downhole borehole portion 3a, the weight fluid will, to a substantial degree, maintain its initial position relative to the surrounding rock structure 5. Thereby, movement of the casing 11 according to the invention will maintain a prescribed placement of weight fluid with properties adjusted to the surrounding structures, the prevailing pressure conditions etc. When the casing 11 has been pulled forward into the desired position, either by having reached a desired distance from the downhole tractor 21, or by a new casing section 11a having to be joined to the upper end of the casing 11, the packers llg, 15 are set again against the borehole wall 5a.
When a new casing section 11a is to be joined to the casing 11, the hoses 31a, 32a are disconnected, a fluid-tight joining is carried out and the join of the casing 11 is tested in the prescribed manner. After the hoses 31a, 32a have been reconnected, the drilling operation and forward movement of the casing 11 are then repeated, as it is described above, until the desired length of the borehole 3 has been reached and the borehole has been cased.
The end cover 11b may advantageously be provided with a passage (not shown) for bottom-hole tools, the passage being fluid-sealingly closable by means of, for example, remote control from the control system 33. Thereby, after release from the end cover 11, the downhole tractor 21 can be retrieved from the borehole in a manner known per se, and another bottom-hole tool may be moved into the open end portion 3a of the borehole 3.
In an alternative embodiment all or a plurality of the packers 15 may be placed on the casing 11 adjacent to the downhole end portion 11a of the casing 11 when the insertion of the casing 15 into the borehole 3 starts. The packers 15 are provided with means (not shown) enabling selective release and fixing of the packers 15 relative to the external mantle surface of the casing 11 and selective fixing of the packer 15 to the borehole wall 5a during the moving forward of the,casing within the borehole 3. Thereby the packers 15 may be set where there is a need for them according to analyses of the borehole 3.
Claims (21)
1. A device for a borehole arrangement, in which a casing (11) for a borehole (3) is formed of at least one casing section (11a), and in which there is placed at a downhole end portion (11b) of the casing (11) at least one downhole tool (21), for example a drilling tool, characterized in that the casing (11) is provided with two or more pipe bores (12, 13a, 13b), each separately extending continuously over a substantial part of the length of the casing (11) and being separated in a fluid-tight manner from adjacent pipe bores (12, 13b, 13a) and from an external annulus (14) defined by the external mantle surface of the pipe (11) and a borehole wall (5a).
2. The device in accordance with claim 1, charac-terized in that at least one pipe bore (13a, 13b) is arranged in the wall (13) of the casing (11).
3. The device in accordance with claim 1, charac-terized in that at least one pipe bore (13a, 13b) is arranged on or at the external mantle surface of the casing (11).
4. The device in accordance with claim 1, charac-terized in that the casing (11) includes one or more channels (16) extending in the axial direction in the external mantle surface of the casing (11) and being arranged to receive one or more lines (17) for fluid conveyance or for the transfer of control and/or monitoring signals between a surface installation (31, 33) and downhole installations (11b, 15, 21) disposed along the casing (11) or at the downhole end portion (11a) of the casing (11).
5. The device in accordance with claim 1, charac-terized in that the casing (11) is provided with one or more annular packers (11g, 15) surrounding the casing (11) and being arranged to define selectively and fluid-communicatingly a portion of the external annulus (14), the packer (11g, 15) being releasably set against the wall (5a) of the borehole (3).
6. The device in accordance with claim 5, charac-terized in that a plurality of the packers (15) are placed on the casing (11) adjacent to the downhole end portion (11a) of the casing (11), the packers (15) including means for the selective release and fixing relative to the external mantle surface of the casing (11) and selective fixing against the borehole wall (5a) at a random point in the axial extent of the casing (11).
7. The device in accordance with claim 5, charac-terized in that the packers (15) are provided with one or more closable packer fluid passages (15a).
8. The device in accordance with claim 7, charac-terized in that the packer fluid passages (15a) are arranged to close to fluid passage in a chosen direction and at the same time stay open to fluid passage in the opposite direction.
9. The device in accordance with claim 7, charac-terized in that the packer fluid passages (15a) are formed as check valves.
10. The device in accordance with claim 5, charac-terized in that the packer (11g, 15) is provided with means for the controlled fixing and release of the packer (11g, 15) relative to the borehole wall (5a).
11. The device in accordance with claim 1, charac-terized in that an end cover (11b) is placed fluid-sealingly on the downhole end portion (11a) of the casing (11).
12. The device in accordance with claim 11, charac-terized in that the end cover (11b) is provided with one or more closable end cover fluid passages (11c, 11d).
13. The device in accordance with claim 12, charac-terized in that the end cover fluid passages (11c, 11d) are arranged to close to fluid passage in a chosen direction and at the same time stay open to fluid passage in the opposite direction.
14. The device in accordance with claim 12, charac-terized in that the end cover fluid passages (11c, 11d) are formed as check valves.
15. The device in accordance with claim 11, charac-terized in that the end cover (11b) is provided with one or more fluid-sealingly closable passages for downhole tools (21).
16. The device in accordance with claim 1, charac-terized in that the downhole tool (21) is a downhole tractor which is arranged to move in an open, uncased portion (3a) of the borehole (3) at the downhole end portion (11a) of the casing (11) and to carry means (24) for working the borehole (3, 3a).
17. The device in accordance with claim 16, charac-terized in that the downhole tool (21) is connected in a fluid-communicating manner to at least one of the pipe bores (12, 13a, 13b) of the casing (11) for the circulation of one or more fluids between a surface installation (31, 32) and the downhole tool (21) with return to the surface installation (31, 32), possibly between the surface installation (31, 32), the downhole tool (21) and the open borehole (3a) with return to the surface installation (31, 32).
18. The device in accordance with claim 16, charac-terized in that the downhole tool (21) is mechanically connected to the downhole end portion (11b) of the casing (11) and is arranged to pull the casing (11) into the open portion (3a) of the borehole (3).
19. The device in accordance with claim 18, charac-terized in that the downhole end portion (11b) of the casing (11) is mechanically connected to a pulling device (23) on the downhole tool (21).
20. The device in accordance with claim 19, charac-terized in that the pulling device (23) is a winch.
21. The device in accordance with claim 1, charac-terized in that at least one of said two or more pipe bores (12, 13a, 13b) is provided with selectively closable openings (11c, 11d) in said downhole end portion (11b) of the casing (11).
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NO20055811 | 2005-12-07 | ||
| NO20055811A NO324448B1 (en) | 2005-12-07 | 2005-12-07 | Device by borehole arrangement |
| PCT/NO2006/000438 WO2007067063A1 (en) | 2005-12-07 | 2006-11-29 | A device for a borehole arrangement |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2629607A1 true CA2629607A1 (en) | 2007-06-14 |
Family
ID=35539176
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002629607A Abandoned CA2629607A1 (en) | 2005-12-07 | 2006-11-29 | A device for a borehole arrangement |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US20080314644A1 (en) |
| CA (1) | CA2629607A1 (en) |
| GB (1) | GB2445702A (en) |
| NO (1) | NO324448B1 (en) |
| WO (1) | WO2007067063A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113279706A (en) * | 2021-07-12 | 2021-08-20 | 中原工学院 | Branch wall pipe for coal seam drilling and coal seam gas extraction system using same |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO333203B1 (en) * | 2008-10-01 | 2013-04-08 | Reelwell As | Downhole utility tool |
| NO335294B1 (en) * | 2011-05-12 | 2014-11-03 | 2TD Drilling AS | Directional drilling device |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4683944A (en) * | 1985-05-06 | 1987-08-04 | Innotech Energy Corporation | Drill pipes and casings utilizing multi-conduit tubulars |
| US5148875A (en) * | 1990-06-21 | 1992-09-22 | Baker Hughes Incorporated | Method and apparatus for horizontal drilling |
| US5816345A (en) * | 1997-04-17 | 1998-10-06 | Keller; Carl E. | Horizontal drilling apparatus |
| DE19745130A1 (en) * | 1997-10-13 | 1999-04-15 | Ruhrgas Ag | Method for laying a line and line with a jacket pipe and a product pipe |
| CA2311158A1 (en) * | 2000-06-09 | 2001-12-09 | Tesco Corporation | A method for drilling with casing |
| GB2365463B (en) * | 2000-08-01 | 2005-02-16 | Renovus Ltd | Drilling method |
| US6615926B2 (en) * | 2000-09-20 | 2003-09-09 | Baker Hughes Incorporated | Annular flow restrictor for electrical submersible pump |
| WO2002057744A2 (en) * | 2001-01-22 | 2002-07-25 | Microgen Systems, Inc. | Automated microfabrication-based biodetector |
-
2005
- 2005-12-07 NO NO20055811A patent/NO324448B1/en not_active IP Right Cessation
-
2006
- 2006-11-29 GB GB0807811A patent/GB2445702A/en not_active Withdrawn
- 2006-11-29 CA CA002629607A patent/CA2629607A1/en not_active Abandoned
- 2006-11-29 WO PCT/NO2006/000438 patent/WO2007067063A1/en active Application Filing
- 2006-11-29 US US12/096,338 patent/US20080314644A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113279706A (en) * | 2021-07-12 | 2021-08-20 | 中原工学院 | Branch wall pipe for coal seam drilling and coal seam gas extraction system using same |
| CN113279706B (en) * | 2021-07-12 | 2023-09-22 | 中原工学院 | Supporting wall pipe for coal bed drilling and coal bed gas extraction system using same |
Also Published As
| Publication number | Publication date |
|---|---|
| NO20055811D0 (en) | 2005-12-07 |
| US20080314644A1 (en) | 2008-12-25 |
| NO324448B1 (en) | 2007-10-22 |
| WO2007067063A1 (en) | 2007-06-14 |
| GB0807811D0 (en) | 2008-06-04 |
| NO20055811L (en) | 2007-06-08 |
| GB2445702A (en) | 2008-07-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP3464791B1 (en) | Apparatus and method to expel fluid | |
| EP3464807B1 (en) | Method to manipulate a well using an overbalanced pressure container | |
| US6923273B2 (en) | Well system | |
| AU743707B2 (en) | Well system | |
| US8122958B2 (en) | Method and device for transferring signals within a well | |
| CA3031514A1 (en) | Method of forming lateral boreholes | |
| US6179058B1 (en) | Measuring method and system comprising a semi-rigid extension | |
| NO327102B1 (en) | Method for drilling a borehole using a micro drilling device and hybrid cable | |
| US11180965B2 (en) | Autonomous through-tubular downhole shuttle | |
| US6868913B2 (en) | Apparatus and methods for installing casing in a borehole | |
| CA3027345A1 (en) | Modular coiled tubing bottom hole assembly | |
| CA2861177C (en) | Piston tractor system for use in subterranean wells | |
| US20080314644A1 (en) | Device for a Borehole Arrangement | |
| US20080264630A1 (en) | Method and Apparatus Suitable For Hole Cleaning During Operations | |
| EP1847679A1 (en) | Underbalanced drilling method into a gas-bearing formation | |
| US20230092034A1 (en) | Underground energy storage systems | |
| NO20141025A1 (en) | System and method of supplementary drilling |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |