CA2075130A1 - Data transmission - Google Patents
Data transmissionInfo
- Publication number
- CA2075130A1 CA2075130A1 CA 2075130 CA2075130A CA2075130A1 CA 2075130 A1 CA2075130 A1 CA 2075130A1 CA 2075130 CA2075130 CA 2075130 CA 2075130 A CA2075130 A CA 2075130A CA 2075130 A1 CA2075130 A1 CA 2075130A1
- Authority
- CA
- Canada
- Prior art keywords
- transducer
- acoustic
- pipe
- borehole
- data
- 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
- 230000005540 biological transmission Effects 0.000 title claims abstract description 13
- 230000006835 compression Effects 0.000 claims abstract description 14
- 238000007906 compression Methods 0.000 claims abstract description 14
- 239000002184 metal Substances 0.000 claims description 6
- 239000007787 solid Substances 0.000 claims description 2
- 239000012636 effector Substances 0.000 abstract description 8
- 239000012530 fluid Substances 0.000 description 11
- 238000012937 correction Methods 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 241000490229 Eucephalus Species 0.000 description 1
- 238000003619 Marshal aromatic alkylation reaction Methods 0.000 description 1
- 241001425800 Pipa Species 0.000 description 1
- 101100029763 Rattus norvegicus Inpp5j gene Proteins 0.000 description 1
- 241000282887 Suidae Species 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000000007 visual effect Effects 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
- E21B47/00—Survey of boreholes or wells
- E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
- E21B47/14—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves
- E21B47/16—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling using acoustic waves through the drill string or casing, e.g. by torsional acoustic waves
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Geology (AREA)
- Acoustics & Sound (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- Remote Sensing (AREA)
- Fluid Mechanics (AREA)
- Environmental & Geological Engineering (AREA)
- Geophysics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geophysics And Detection Of Objects (AREA)
Abstract
ABSTRACT
Data Transmission Data from an effector at the end of a pipe in a borehole is transmitted to the surface as acoustic compression waves in the pipe. Similarly instructions can be passed from the surface to the end effector by acoustic compression waves in the pipe.
Data Transmission Data from an effector at the end of a pipe in a borehole is transmitted to the surface as acoustic compression waves in the pipe. Similarly instructions can be passed from the surface to the end effector by acoustic compression waves in the pipe.
Description
207~130 P/87~9/P48 Pata Transmission This invention relates to data transmi~sion, and particularly to data transmission along a borehole.
After a borehole has been drilled, for example to produce oil, it is often necessary to carry out operations within it. These operations include inspection of the ~orehole walls, the formation and removal of plugs and treating the borehole wall to increase fluid flow rates among others.
one method of doing this is to pass a narrow bore c~ntinuous tu~e with a s4nsor or end effector at its end down the borehole. In order to monitor and control thi6 sensor/effector data must be passed up the borehole and instructions must be passed down. This ls ~one using ~able such as a multi-core or coaxial cable, passin~ down the centre of the tube.
There are three main problems associated with this technique, the f irst is that the environment at the bott~m of the ~orehole can be very different from that at the top, temperatures up to 200C and pressures of 15,000 p~i can be 207~130 ~ 4 ~3 encount~red at the bottom o~ a borehole. This can cause considerabla problems as the electrical properties of the cahle ~han~e as the ~nvironm~nt around it ch~ngec r~culting in a wire having different characteristia~ along its length.
This can result in unacceptable electrical attenuation in signals passing along the cable. Secondly, in addition to the changes in conditions along t~ borehole's length conditions within the tube are extremely hostile, apart from the preæsures and temperatures naturally present within the borehole it is often necessary to pump fluid under hiqh pressure down the pipe to power end effectors such as drillc. Thi~ produces an unacceptably high rate of cable failures, and withdrawing the pipe and replacing the cable is both time consuming ~nd costly. The third problem is that the lengths of the cable and tube must of course be matched precisely and the length of the tube must be matched to t~e depth in the borehole at which the worX or exa~ination is to be done and as a result a very large numb~r of tubes and cables must be held as ~tock at ~reat expense, which is clearly undesirable.
This invention was intended to produce a data transmission system at least partially overcoming these problems.
Tl~i~ inventl~n p~ovi~es ~ d~t~ tr~nsmission ~y~tem ~Dr use in a borehole comprising a first acoustic transducer, a second acou~tic transducer and a continuous solid element, the first acoustic transducer being associated wit~ the element at a first point and the second acoustic transdu~er being associated with the element at a second point spaced apart from the first, the first transducer being arranged to produce acoustic waves in the ele~ent and the second transducer being arranged to detect these acoustic waves.
This allows communication between the end of a pipe in a borehole and the surface using the pipe itsel$ to carry the signal; this eliminates the problem of ca~le failure and becausQ the acoustic properties of the pipe will not change in such a way as to prevent acoustic wave transmission due to the pressure an~ temperature changes encountered within boreholes the problem of variable attenuation with the signals Will ~e reduced. Since no cable is needed within the pipe the amount of stock which must be held is reduced, saving money.
Advantageously acoustic co~pression waves are used because the amplitude of acoustic compression waves decays ~ore 810wly over distance than acoustic tranqverse waves, in othe~ words they suffer ~ewer losses, and t~ey travel ' ~ ' ` ` ~
After a borehole has been drilled, for example to produce oil, it is often necessary to carry out operations within it. These operations include inspection of the ~orehole walls, the formation and removal of plugs and treating the borehole wall to increase fluid flow rates among others.
one method of doing this is to pass a narrow bore c~ntinuous tu~e with a s4nsor or end effector at its end down the borehole. In order to monitor and control thi6 sensor/effector data must be passed up the borehole and instructions must be passed down. This ls ~one using ~able such as a multi-core or coaxial cable, passin~ down the centre of the tube.
There are three main problems associated with this technique, the f irst is that the environment at the bott~m of the ~orehole can be very different from that at the top, temperatures up to 200C and pressures of 15,000 p~i can be 207~130 ~ 4 ~3 encount~red at the bottom o~ a borehole. This can cause considerabla problems as the electrical properties of the cahle ~han~e as the ~nvironm~nt around it ch~ngec r~culting in a wire having different characteristia~ along its length.
This can result in unacceptable electrical attenuation in signals passing along the cable. Secondly, in addition to the changes in conditions along t~ borehole's length conditions within the tube are extremely hostile, apart from the preæsures and temperatures naturally present within the borehole it is often necessary to pump fluid under hiqh pressure down the pipe to power end effectors such as drillc. Thi~ produces an unacceptably high rate of cable failures, and withdrawing the pipe and replacing the cable is both time consuming ~nd costly. The third problem is that the lengths of the cable and tube must of course be matched precisely and the length of the tube must be matched to t~e depth in the borehole at which the worX or exa~ination is to be done and as a result a very large numb~r of tubes and cables must be held as ~tock at ~reat expense, which is clearly undesirable.
This invention was intended to produce a data transmission system at least partially overcoming these problems.
Tl~i~ inventl~n p~ovi~es ~ d~t~ tr~nsmission ~y~tem ~Dr use in a borehole comprising a first acoustic transducer, a second acou~tic transducer and a continuous solid element, the first acoustic transducer being associated wit~ the element at a first point and the second acoustic transdu~er being associated with the element at a second point spaced apart from the first, the first transducer being arranged to produce acoustic waves in the ele~ent and the second transducer being arranged to detect these acoustic waves.
This allows communication between the end of a pipe in a borehole and the surface using the pipe itsel$ to carry the signal; this eliminates the problem of ca~le failure and becausQ the acoustic properties of the pipe will not change in such a way as to prevent acoustic wave transmission due to the pressure an~ temperature changes encountered within boreholes the problem of variable attenuation with the signals Will ~e reduced. Since no cable is needed within the pipe the amount of stock which must be held is reduced, saving money.
Advantageously acoustic co~pression waves are used because the amplitude of acoustic compression waves decays ~ore 810wly over distance than acoustic tranqverse waves, in othe~ words they suffer ~ewer losses, and t~ey travel ' ~ ' ` ` ~
2 0 7 ~ 1 3 0 P/87ls/p48 faster, commonly up to 10 times ~aster than acoustic t~an~verse wav~s in metal pipR8.
It is desirable to have the facility for two way ~ignal traffia along the element, often data must be passed ~rom sensors down a borehole to a controller on the sur~ace who sends instructions bac~ down the borehole to an effector associated with t~e sensor. This can be achieved either by mAking each transducer botn an acoustic wave producer and detector or by having a third transducer local to the second point and a forth transducer local to the first point and having the third transducer arranged to produce acoustic wave6 ~nd the ~orth transducer arranged to re~:eive them.
Preferably the elèment is a continuous metal tube because this allows a pipe in a borehole to ba used to carry the acoustic waves and a pipe forms a very good carrier of acou~tic compression waves.
Ad~a~tageously the element is a pipe down a borehole and the first and second points are inside and outside the borehole respectively, allowing data to be carried from a sensor down a borehole to the surface.
Apparatus employing the invention will now be .. , . : , , .
, ' ' . ` , ..
2~5130 ~escrl~ed ~y way o~ example only with reference to the accompanying diagrammatic figures in which:
Figure 1 shows an overall view of a data transmi~sion system linking a device down a ~qrehole with the surface;
Figure 2 shows the device down the bor~hole in more detail; and Figure 3 shows the apparatus on the surf ace in more detail, similar parts having the same referenc2 numerals throughout.
~ eferring to Fi~ure 1 a borehole 1 is shown, only the top and bottom of the borehole 1 are illustrated, the centr~l region of the borehole 1 being omitted. In the borehole 1 is a concrete plug 2 which blocks the borehole 1.
In order to remove the concrete plug 2 a drill 3 on the end of a cont1nuous steel pipe 4 is passed down the borehole 1.
The pipe 4 does not rotate ~ut is fed up an~ ~own the ~o~ch~ls 1 ~y ~u~ ~el~drl~eJ c. ~he tus h~lt~riv~ 5 ~pacsd ~ymmetrically around the pipe 4 and each comprise motor driven wheels 6 urged against the pipe 4 and running within a belt 7, each beltdrive 5 operating in a similar .
2 0 7 ~
P/8719/P4~
manner to a ~terPil~r-trnck~ ~y altering th* IllvL~r power applied to the belt ~iYes .5 ~ nnt 4nly c~n the pipa 4 ~
moved up and down the borehole 1, but the force with which ~he drill 3 is urged against the concrete plug 2 can be ~ltered.
The motor system powering the beltdrives 5 are omitted f or si~p~ icity since beltdrives of this type are well known and need not be descri~ed in detail here.
As the pipe 4 is fed up and down the borehole 1 the surplus pipe 4 is removed from or added to a reel 8~
The pipe 4 does not rotate, so in order to power the drill 3 ~luid is pumped down the in~erior of the pipP 4 by a pump 9 which is linked to the end of the pipe 4 by a pipe lo. ~l~nis fluid is used to drive the drill 3 by way of a turbine 11. After passing through the turbine 11 the fluid passes out of the pipe 4 and passes back up the borehole around the pipe 4 to the surfa~e. At the s~rface the fluid leaves the borehole 1 and passes along a pipe 12 and is dumped. At the top of the borehole 1 a seal 13 is provided t~ U ~ho ~o ~ ~V ~IIVV~ wl~hou~ allowlng ~ne rlul~ ~o escape.
20~13'~
P/8719/P4~
~ e~err~ng to Figure 2 the bottom end of the plpe 4 is shown in more detail. Fluid passes ~own the bore of the pipe 4, and into a tapered section 14 leading to a narrow hnrP ~R~t; ~n 16 Th~ t~p4r~d ~d ~ u ~ C~lU~
and 15 are defined by an inner tube 16 arranged coaxially withln the tube 4 to leave an annular gap 17 between the two tu~es 4 and 16.
When th~ fluid r~aches the end o~ the tubes 4 and 1~
it pas~es through the turbine 11 attached to the drill 3 and exits from the periphery of the turbine 11 into the borehole 1. Thus the pressure of the fluid drives the drill 3.
The annular gap 17 contains the electronic~ used to transfer data between the bo~tom and top of the borehole ~.
A rotational transducer 18 senses the rotation of the drill 3 and produces electrical signals giving the speed of rotation of the drill 3 and supplies them to a d~ta acquisition system 19. ~ force transducer 20 senses the force exerted on the drill 3 by the tube 4 and supplies electrical signals containing this information to the data acquisition ~ystem 19. A pressure transducer 21 ~enses the pre~ure o~ the fluid pa~ g ~wn the tube 4 an~ supplles electrical signals containing this information to the data .
acquis~tion sy~tem 19.
The data acguisition system l9 marshals the data from ths three transducers 18, 2~ and 21 into a serial data s~ream and ~d~ error corr~ction codoc. It th~n supplies this data stream to a first acoustic transducer 22 which converts the datà stream into a 6eries of acoustic compression waves in the wall of the pipe 4. The first acoustic transducer 22 is linked to the pipe 4 by an acoustic impedance matching element 23.
A forth acoustic transducer 24 senses acoustic compression waves in the pipe 4 and conver~s them into electrical signals wh~ch are supplied to the data acquisition system l9.
The electronics at the bottom of the pipe 4 are all powered by a battery 25.
Referring to Figure 3, at the top of the borehole the pipe 4 passes through a sliding seal 13 which allows the pipe to move up and down the borehole 1 without allowing the fluid to escape.
A second acoustic transducer 26 is situated adjacent 2 0 ~ 0 P/8 7 1~/P4 8 _ g _ the pip~ 4 above the ~;liding seal 13, the second acoustic transducer 26 is a non-contact magnetic tran~ducer which produces electrical signals corresponding to longitudinal ~ovements of the pipe 4. These signals are supplied to a processor 27. The processor 27 analyses the signals from the second transducer 26 and extracts the parts of the signal relati~g to acoustic compression waves in the wall ~f the pipe 4, rejecting noise due to the various pieces of moving machinery associated wit~ the pipe 4, such as reel 8, ~eltdrives 5, pump 9 and the drill 3, and also rejecting signal~ produced by the movement of the pipe 4 in the borehole 1 ~ he processor 27 reconstructs the data stream sent by the data acquisition system 19 using the error correction codes to replace any data whlch has been lost. Data can be lost ~ue to destructive interference or being swamped by noise.
The processor 27 also receives data on lines 2~ from sensor at the top of the ~orehole 1, this data gives the pressure at which fluid is pumped into the pipe 4 by the pump 9 and the length of pipe 4 within the borehole 1, which is derived from the rotational movement of the reel 8.
20~130 ~ 10 -The proaessar 27 d~splays all of this data on a visual display unit (V.D.U.) 29 and stores it in a fir~t memory 30.
The processor compares the data with its instructions stored in a ~econd memory 31 and decides what actions are necessary.
The processor 27 then instructs the beltdrives 5 and pump ~ aG nocoEEa~y ~long lin~ 3~ and organis instructions for the elements at the bottom of the pipe 4 as a serial data stream and adds error correction codes. It then supplies this serial data stream to a third acoustic transducer 33 which is a non-contact magnetic transducer wh~ch converts the data stream into acoustic compression waves in the plpe 4.
If necessary the instructions stored in the first memoxy 30 can be altered by coNmands along a line 34, this line 34 can also be used to instruct the processor 27 diroctly.
When the compression waves generated by the third tran6ducer 33 reach the bottom of the pipe 4 they are picked up by the forth transducer 24 and supplied to the data acquisltion system ls. This reconstructs the data stream using the error correction codes to replace any lost data in 2~7~13~
the same way a~ the processor 27 and takes the actlon t~e data stream instructs it to take.
The forth transduoer 24 will of course pick up the acoustlc waves generated by the first acoustic transducer 22 in the pipe 4, similarly the second transducer 26 will pick up the acoustic waves generated by the third transducer 33.
In bo~h cases the signal processor, data acquisition ~ystem 19 and processor 27 respectively, will ignore the acoustic waves it has produced itself.
In the example a~ove although thare is little that the system at the b~ttom o~ the pipe 4 can do in response to instructions from above because it does not in~lude an end erfector~ it is useful to be a~le to pass instructions to repeat signals or initiate sel~-test proce~ures or to go into or oUt of power conservin~ modes. In other types of end effector fitted to the pipe 4 more ins~ructions may be necessary~ possible end effectors could be anything used in borehole logging including for example, cement layeræ, inflatable plugs, grabs, perforators to modify the walls of the borehole l, sensitive signa~ generators or receivers, neutron flUX detectors resistivity measurement tools and ultrasonic or TV scanners.
2 ~ 3 0 P/~71 In the case of seismic signal generators or ultrasonic or TV sc~nner~ in particular a high data rate for transmission up the pipe ~ is desirable.
Error correction code system~ suitable for transmittin~ data in a hi~h noise environment are well known per se, so it is unnecessary to described them in detail here.
Although the example described uses acoustic co~pression waves to pass data alonq a continuous pipe a similar system could be used ~or communication anywhere where a continuous link of a material with good acoustic properties exists, for exa~ple railway signalling systems and trains could communicate by acoustic compression waves ~long railway lines and pumping st~tions could communicate among themselves and with pipeline "pigs" by aco~stic compression waves along metal pipelines. The precise form o~ the ~iy~;tems for producing and sensinq the acoustic waves will depend on the system and the characteristics of the transmitting member and the amount and type of relative movement betwe~n the transmitting member and the producing or sensing element.
Although acoustic compression waves are used in the P~87l9~Pæo75~ .~0 -- 13 ~
example above, acoustic transverse waves could be used, however compression wave~ are pre~erred because they travel faster and generally suffer fewer losses.
It may be preferred to provide the forth transducer 24 with an impedance matchin~ element similar to the impedance match~ng network 23.
Instead of having separate transmitting transducers 22 and 26 and receiving transducers 24 and 33 a singl e transmitting and receiving transducer could be used at the lower end of the drill pipe 4 or on the surface, however this would require careful sychronisation of the data acqui~ition system lg and the processor 27 to ensure that data was not lost due to a transducer transmittin~ while acoustic waves from the Qther end of the drill pipe ~ were ~rriving at it.
The transducer 26 is a non-contact magnetic transducer so that it can detect acoustic waves in the pipe 4 without interfering with mo~ements of the pipe 4. Alternatively, other types of transducers could be used such as an accelerometer or a piezoelectric transducer as used in a record stylus.
2~7~13~
~lthough the use of a steel pipe 4 is described this invention could be employed with pipes o~ any other metal or alloy, or even with other materials such as plastics provi~ed they had suitable acoustic propagation properties
It is desirable to have the facility for two way ~ignal traffia along the element, often data must be passed ~rom sensors down a borehole to a controller on the sur~ace who sends instructions bac~ down the borehole to an effector associated with t~e sensor. This can be achieved either by mAking each transducer botn an acoustic wave producer and detector or by having a third transducer local to the second point and a forth transducer local to the first point and having the third transducer arranged to produce acoustic wave6 ~nd the ~orth transducer arranged to re~:eive them.
Preferably the elèment is a continuous metal tube because this allows a pipe in a borehole to ba used to carry the acoustic waves and a pipe forms a very good carrier of acou~tic compression waves.
Ad~a~tageously the element is a pipe down a borehole and the first and second points are inside and outside the borehole respectively, allowing data to be carried from a sensor down a borehole to the surface.
Apparatus employing the invention will now be .. , . : , , .
, ' ' . ` , ..
2~5130 ~escrl~ed ~y way o~ example only with reference to the accompanying diagrammatic figures in which:
Figure 1 shows an overall view of a data transmi~sion system linking a device down a ~qrehole with the surface;
Figure 2 shows the device down the bor~hole in more detail; and Figure 3 shows the apparatus on the surf ace in more detail, similar parts having the same referenc2 numerals throughout.
~ eferring to Fi~ure 1 a borehole 1 is shown, only the top and bottom of the borehole 1 are illustrated, the centr~l region of the borehole 1 being omitted. In the borehole 1 is a concrete plug 2 which blocks the borehole 1.
In order to remove the concrete plug 2 a drill 3 on the end of a cont1nuous steel pipe 4 is passed down the borehole 1.
The pipe 4 does not rotate ~ut is fed up an~ ~own the ~o~ch~ls 1 ~y ~u~ ~el~drl~eJ c. ~he tus h~lt~riv~ 5 ~pacsd ~ymmetrically around the pipe 4 and each comprise motor driven wheels 6 urged against the pipe 4 and running within a belt 7, each beltdrive 5 operating in a similar .
2 0 7 ~
P/8719/P4~
manner to a ~terPil~r-trnck~ ~y altering th* IllvL~r power applied to the belt ~iYes .5 ~ nnt 4nly c~n the pipa 4 ~
moved up and down the borehole 1, but the force with which ~he drill 3 is urged against the concrete plug 2 can be ~ltered.
The motor system powering the beltdrives 5 are omitted f or si~p~ icity since beltdrives of this type are well known and need not be descri~ed in detail here.
As the pipe 4 is fed up and down the borehole 1 the surplus pipe 4 is removed from or added to a reel 8~
The pipe 4 does not rotate, so in order to power the drill 3 ~luid is pumped down the in~erior of the pipP 4 by a pump 9 which is linked to the end of the pipe 4 by a pipe lo. ~l~nis fluid is used to drive the drill 3 by way of a turbine 11. After passing through the turbine 11 the fluid passes out of the pipe 4 and passes back up the borehole around the pipe 4 to the surfa~e. At the s~rface the fluid leaves the borehole 1 and passes along a pipe 12 and is dumped. At the top of the borehole 1 a seal 13 is provided t~ U ~ho ~o ~ ~V ~IIVV~ wl~hou~ allowlng ~ne rlul~ ~o escape.
20~13'~
P/8719/P4~
~ e~err~ng to Figure 2 the bottom end of the plpe 4 is shown in more detail. Fluid passes ~own the bore of the pipe 4, and into a tapered section 14 leading to a narrow hnrP ~R~t; ~n 16 Th~ t~p4r~d ~d ~ u ~ C~lU~
and 15 are defined by an inner tube 16 arranged coaxially withln the tube 4 to leave an annular gap 17 between the two tu~es 4 and 16.
When th~ fluid r~aches the end o~ the tubes 4 and 1~
it pas~es through the turbine 11 attached to the drill 3 and exits from the periphery of the turbine 11 into the borehole 1. Thus the pressure of the fluid drives the drill 3.
The annular gap 17 contains the electronic~ used to transfer data between the bo~tom and top of the borehole ~.
A rotational transducer 18 senses the rotation of the drill 3 and produces electrical signals giving the speed of rotation of the drill 3 and supplies them to a d~ta acquisition system 19. ~ force transducer 20 senses the force exerted on the drill 3 by the tube 4 and supplies electrical signals containing this information to the data acquisition ~ystem 19. A pressure transducer 21 ~enses the pre~ure o~ the fluid pa~ g ~wn the tube 4 an~ supplles electrical signals containing this information to the data .
acquis~tion sy~tem 19.
The data acguisition system l9 marshals the data from ths three transducers 18, 2~ and 21 into a serial data s~ream and ~d~ error corr~ction codoc. It th~n supplies this data stream to a first acoustic transducer 22 which converts the datà stream into a 6eries of acoustic compression waves in the wall of the pipe 4. The first acoustic transducer 22 is linked to the pipe 4 by an acoustic impedance matching element 23.
A forth acoustic transducer 24 senses acoustic compression waves in the pipe 4 and conver~s them into electrical signals wh~ch are supplied to the data acquisition system l9.
The electronics at the bottom of the pipe 4 are all powered by a battery 25.
Referring to Figure 3, at the top of the borehole the pipe 4 passes through a sliding seal 13 which allows the pipe to move up and down the borehole 1 without allowing the fluid to escape.
A second acoustic transducer 26 is situated adjacent 2 0 ~ 0 P/8 7 1~/P4 8 _ g _ the pip~ 4 above the ~;liding seal 13, the second acoustic transducer 26 is a non-contact magnetic tran~ducer which produces electrical signals corresponding to longitudinal ~ovements of the pipe 4. These signals are supplied to a processor 27. The processor 27 analyses the signals from the second transducer 26 and extracts the parts of the signal relati~g to acoustic compression waves in the wall ~f the pipe 4, rejecting noise due to the various pieces of moving machinery associated wit~ the pipe 4, such as reel 8, ~eltdrives 5, pump 9 and the drill 3, and also rejecting signal~ produced by the movement of the pipe 4 in the borehole 1 ~ he processor 27 reconstructs the data stream sent by the data acquisition system 19 using the error correction codes to replace any data whlch has been lost. Data can be lost ~ue to destructive interference or being swamped by noise.
The processor 27 also receives data on lines 2~ from sensor at the top of the ~orehole 1, this data gives the pressure at which fluid is pumped into the pipe 4 by the pump 9 and the length of pipe 4 within the borehole 1, which is derived from the rotational movement of the reel 8.
20~130 ~ 10 -The proaessar 27 d~splays all of this data on a visual display unit (V.D.U.) 29 and stores it in a fir~t memory 30.
The processor compares the data with its instructions stored in a ~econd memory 31 and decides what actions are necessary.
The processor 27 then instructs the beltdrives 5 and pump ~ aG nocoEEa~y ~long lin~ 3~ and organis instructions for the elements at the bottom of the pipe 4 as a serial data stream and adds error correction codes. It then supplies this serial data stream to a third acoustic transducer 33 which is a non-contact magnetic transducer wh~ch converts the data stream into acoustic compression waves in the plpe 4.
If necessary the instructions stored in the first memoxy 30 can be altered by coNmands along a line 34, this line 34 can also be used to instruct the processor 27 diroctly.
When the compression waves generated by the third tran6ducer 33 reach the bottom of the pipe 4 they are picked up by the forth transducer 24 and supplied to the data acquisltion system ls. This reconstructs the data stream using the error correction codes to replace any lost data in 2~7~13~
the same way a~ the processor 27 and takes the actlon t~e data stream instructs it to take.
The forth transduoer 24 will of course pick up the acoustlc waves generated by the first acoustic transducer 22 in the pipe 4, similarly the second transducer 26 will pick up the acoustic waves generated by the third transducer 33.
In bo~h cases the signal processor, data acquisition ~ystem 19 and processor 27 respectively, will ignore the acoustic waves it has produced itself.
In the example a~ove although thare is little that the system at the b~ttom o~ the pipe 4 can do in response to instructions from above because it does not in~lude an end erfector~ it is useful to be a~le to pass instructions to repeat signals or initiate sel~-test proce~ures or to go into or oUt of power conservin~ modes. In other types of end effector fitted to the pipe 4 more ins~ructions may be necessary~ possible end effectors could be anything used in borehole logging including for example, cement layeræ, inflatable plugs, grabs, perforators to modify the walls of the borehole l, sensitive signa~ generators or receivers, neutron flUX detectors resistivity measurement tools and ultrasonic or TV scanners.
2 ~ 3 0 P/~71 In the case of seismic signal generators or ultrasonic or TV sc~nner~ in particular a high data rate for transmission up the pipe ~ is desirable.
Error correction code system~ suitable for transmittin~ data in a hi~h noise environment are well known per se, so it is unnecessary to described them in detail here.
Although the example described uses acoustic co~pression waves to pass data alonq a continuous pipe a similar system could be used ~or communication anywhere where a continuous link of a material with good acoustic properties exists, for exa~ple railway signalling systems and trains could communicate by acoustic compression waves ~long railway lines and pumping st~tions could communicate among themselves and with pipeline "pigs" by aco~stic compression waves along metal pipelines. The precise form o~ the ~iy~;tems for producing and sensinq the acoustic waves will depend on the system and the characteristics of the transmitting member and the amount and type of relative movement betwe~n the transmitting member and the producing or sensing element.
Although acoustic compression waves are used in the P~87l9~Pæo75~ .~0 -- 13 ~
example above, acoustic transverse waves could be used, however compression wave~ are pre~erred because they travel faster and generally suffer fewer losses.
It may be preferred to provide the forth transducer 24 with an impedance matchin~ element similar to the impedance match~ng network 23.
Instead of having separate transmitting transducers 22 and 26 and receiving transducers 24 and 33 a singl e transmitting and receiving transducer could be used at the lower end of the drill pipe 4 or on the surface, however this would require careful sychronisation of the data acqui~ition system lg and the processor 27 to ensure that data was not lost due to a transducer transmittin~ while acoustic waves from the Qther end of the drill pipe ~ were ~rriving at it.
The transducer 26 is a non-contact magnetic transducer so that it can detect acoustic waves in the pipe 4 without interfering with mo~ements of the pipe 4. Alternatively, other types of transducers could be used such as an accelerometer or a piezoelectric transducer as used in a record stylus.
2~7~13~
~lthough the use of a steel pipe 4 is described this invention could be employed with pipes o~ any other metal or alloy, or even with other materials such as plastics provi~ed they had suitable acoustic propagation properties
Claims (6)
1. A data transmission system for use in a borehole comprising a first acoustic transducer, a second acoustic transducer and a continuous solid element, the first acoustic transducer being associated with the element at a first point and the second acoustic transducer being associated with the element at a second point spaced apart from the first, the first transducer being arranged to produce acoustic waves in the element and the second transducer being arranged to detect these acoustic waves.
2. A data transmission system as claimed in claim in which the second transducer is also arranged to produce acoustic waves in the element and the second transducer is also arranged to detect these acoustic waves.
3. A data transmission system as claimed in claim in which a third acoustic transducer is associated with the element local the second point and a forth acoustic transducer is associated with the element local the first point, the third transducer being arranged to produce acoustic waves in the element and the forth transducer being arranged to detect these acoustic waves.
4. A data transmission system as claimed in any preceding claim wherein the acoustic waves are acoustic compression waves.
5. A data transmission as claimed in any preceding claim where the element is a continuous metal pipe.
6. A data transmission system as claimed in claim 5 where the metal pipe is down a borehole and the first and second points are inside and outside the borehole respectively.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB919116487A GB9116487D0 (en) | 1991-07-31 | 1991-07-31 | Data transmission |
| GB9116487.1 | 1991-07-31 | ||
| GB9120420A GB2258331A (en) | 1991-07-31 | 1991-09-25 | Data transmission |
| GB9120420.6 | 1991-11-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2075130A1 true CA2075130A1 (en) | 1993-02-01 |
Family
ID=26299314
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2075130 Abandoned CA2075130A1 (en) | 1991-07-31 | 1992-07-31 | Data transmission |
Country Status (2)
| Country | Link |
|---|---|
| EP (1) | EP0526246A2 (en) |
| CA (1) | CA2075130A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5732776A (en) * | 1995-02-09 | 1998-03-31 | Baker Hughes Incorporated | Downhole production well control system and method |
| US6442105B1 (en) | 1995-02-09 | 2002-08-27 | Baker Hughes Incorporated | Acoustic transmission system |
| GB2357527B (en) * | 1999-12-22 | 2002-07-17 | Schlumberger Holdings | System and method for torsional telemetry in a wellbore |
| CN101451432B (en) * | 2007-12-04 | 2012-07-18 | 中国石油天然气集团公司 | High precision digital sonic wave variable density calibration method |
| CN106593424B (en) * | 2016-12-05 | 2019-09-10 | 中国矿业大学 | Back rock Protodyakonov coefficient based on sound level meter is with brill detection method |
| CN112412401A (en) * | 2020-12-04 | 2021-02-26 | 中国石油天然气股份有限公司 | Wireless measurement-based pumping unit intermittent pumping control system and method thereof |
-
1992
- 1992-07-31 CA CA 2075130 patent/CA2075130A1/en not_active Abandoned
- 1992-07-31 EP EP19920307022 patent/EP0526246A2/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| EP0526246A2 (en) | 1993-02-03 |
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