CA2187423A1

CA2187423A1 - An acoustic transmisson system

Info

Publication number: CA2187423A1
Application number: CA002187423A
Authority: CA
Inventors: Paulo Tubel; Albert A. Ii Mullins; Kevin R. Jones; Frank D. Richardson
Original assignee: Individual
Current assignee: Baker Hughes Holdings LLC
Priority date: 1995-02-09
Filing date: 1996-02-09
Publication date: 1996-08-15
Also published as: US6192980B1; NO960518D0; AU708330B2; AU5022396A; WO1996024751A1; US6192988B1; US20020020533A1; WO1996024747A1; CA2187422A1; NO960518L; NO960527D0; GB2302432A8; GB9621099D0; GB2302114B; CA2187422C; US5732776A; US6464011B2; GB2302432A; AU4980696A; GB2302114A

Abstract

An acoustic transmission system is presented, wherein communication is transmitted over an acoustic medium comprising production tubing, well casingor over continuous tubing in a well (e.g., coil tubing, chemical injection tubing or dewatering string). More specifically, the acoustic medium has an acoustic tool asso-ciated therewith, which is located downhole with the sensors and electromechanical devices typically employed in a well, and an acoustic tool associated therewith up-hole. The downhole sensors are connected to the downhole acoustic tool for acoustic communication. The acoustic tool includes a piezoelectric ceramic transducer (i.e., a stack of piezoelectric elements) or an accelerometer for transmitting or receiving acoustic signals transmitting through the medium.

Description

WO 96/24751 P~TlUss610181s AN ACOUSTIC TRANSMISSION SYSTEM
Back~round of the Invention:
The present inventions relates to an acoustic system and method in a well.
More specifically, the present invention relates to an acoustic system and method for acoustic . ., . " " ~ ;. ", over an acoustic medium comprising production tubing, well casing or over continuous tubing in a well (e.g., coil tubing, chemical injection tubing or dewatering st}ing).
After an oil or gas well has been drilled it is completed. A completed hole includes a casing defining the hole with production tubing installed within the hole.
Oil or other petroleum products are extracted via the production tubing, as is well known. Typically, the production tubing includes sensors and clc~
devices located downhole for control of the production well. The sensors monitordownhole parameters (such as pressure, l~ a~ul~, flow, gas influx, etc.) and thecl~ 1 devices include, e.g., a sliding sleeve or packer, a valve or start/stop a pump or other fluid flow device.
('. " ", . . ~ uphole/downhole with the sensors and the cl~
devices is generally ~. ~ . ,.,.1.l;~l,. ~I over a wireline, as is well known in the industry.
Another way 1 - ,,, ,,,,, l, ,;- ,, l;, ,~ is described in U.S. Patent No. ~ 283,768 ('768) assigned to the assignee hereof. The '768 patent discusses acoustic telemetry in the completion liquid in the annular space between the casing and the production tubing in a WO 96/247~ u~ 6~!UI9 production well, i.e, the completion liquid is the acoustic ~ , medium. The acoustic transducer disclosed in the '768 patent generates acoustic waves in the liquid.
s~nnm:~rV of the Inventir n The above-discussed and other drawbacks and A~ of the prior art are overcome or alleviated by the acoustic ~ " system of the present invention. In accordance with the present invention acoustic c " "" " ~ is transmitted over production tubing (the production tubing is the acoustic ~ ;..., medium) or over coil tubing in the production tubing.
A production well (i.e., completed well) is enclosed by a casing with a rig at the surface and has production tubing installed therein. The lower end of productiontubing is perforated to provide a path for the flow of oil from the L~Luualllull bed up the center of the production tubing. A packer is provided to isolate this lower end from the upper portion of the well. Sensors are provided to monitor downhole parameters (such as pressure, ~ aLu~c;, flow, gas influx, etc.) and ~I.,.,lll " ~ I ~A- I;r ~RI devices include, e.g., a sliding sleeYe or packer, a valve or pump or other fluid flow devices for control. Such sensors and/or ~ ": ~l devices may be mounted downhole in the production well itself and/or; I .- " ~ d into the production tubing, as are well known. A downhole acoustic ~ rm tool in accordance witn the present invention is provided for acoustic telemetry. An uphole acoustic r ~ ,.. ,. ~ .: ~l ;. ., . tool is 20 provided for acoustically, . .. , " " " " ;, .~l; "~ with the downhole tool.
The downhole acoustic tool in accordance with a first emhorlimPnt, comprises a cylindrical mandrel having rotary l,OlllI.,.,~iUll:. the ends tnereof. This tool, when installed in a production well, becomes part of the production tubing. An opening extends l-~n~itllrlin~l ly through the mandrel perrnitting flow of oil or gas Il~ uu~;ll.
The mandrel includes a plurality of machined cavities wherein the ~ "~ of the tool are housed. A riP7r~PlPrtrir ceramic transducer (i.e., a stack of I~L,~u~lc~,lli~, elements) is mounted in one of the cavities in a cornpressed state and in intimate contact with the mandrel for acoustic coupling therewith. Transformer coils, an electronic assembly and a battery pack assembly are mounted in another cavity. A

WO96/24751 2 J ~ 7 4 ~ 3 PCrluss6101819 sleeve is connected onto the mandrel by a rotary rr~nn~rlirn The sleeve covers the cavities in the mandrel. A locking ring attached at another rotary connection and a shoulder sub are provided to secure the sleeve on the mandrel. The mandrel, if disposed downhole in a production string without the sleeve would subject the mandrel to high stresses, whereby the ~ ocL,~ iG stack therein would be unloaded or overloaded resulting in poor acoustic coupling. The sleeve, by way of the rotary 1 .., .. If ~ ~i. " ,~ absorbs much of these stress, whereby proper loading on the stack is m ;nt~ir.fd In accordance with a second rl~ I, a coil tubing is extended down the opening of the production tubing. An uphole acoustic tool (e.g., an acoustic receiver, for example. an ac.,cl~lu~ tc~) and a downhole æoustic tool (e.g., an acoustic transmitter, for example a ~ f I ~ ic device~ are provided on coil tubing for acoustic telemetr~ in accordance with this alternate ;,lllbvdi~ L. It will be ~,,c ' thattwo-way acoustic .. , .. , .. " .:~ ~ ;.. , is within the scope of the present invention, e.g., l~:~-.. If ~ c ll~la~ a upholeanddownhole. Itwillfurtherbeappreciatedthatcoiltubin~ is also employed while drilling a borehole, and acoustic telemetry as described herein ma~ be applied such coil tubing. Also, the acoustic telemetry of the present invention. as applied to coil tubing, may be applied to other continuous tubing strings, e.g., chemical injection tubing, a dewatering stfing and the like. The downhole sensors are connected to the downhole acoustic tool for acoustic i., ." " ", ~. ,;, ,.: ;,~"
Inaccordancewithathirdr~,.1.o.1;,. ,l adownholeacousticc~.,.""",.:.,..icn tool is pro-~ided for acoustic telemetry which is integral to casmg. An uphole acoustic f ~ tool is provided for acoustically ~ over with the downhole tool.
The above-discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings.

wo 96124751 PCr/uss6/0181s ~ ~7~

Brief DescriRtion of the Drawin~s:
Referring now to the drawings, wherein like elements are numbered alike in the several FIGURES:
FIGURE 1 is a ~ view depicting the multiwell/multizone control system of the present invention for use in controlling a plurality of offshore well platforms;
FIGURE 2 is an enlarged ~ ;. view of a portion of FlGURE 1 depicting a selected well and selected zones in such selected well and a downhole control system for use therewith;
10 FIGURE3isanenlargedil; ~,,.. ".. li~ viewofaportionofFlGURE2 depicting control systems for both open hole and cased hole completion zones;
FIGURE 4 is a block diagram depicting the multiwell/multizone control system irl accordance with the present invention;
FIGUF~E 5 is a block diagram depicting a surface control system for use with the multiwell/multizone control system of the present invention;
FIGURE 6 is a ~ ;c elevation view of a production well employing an acoustic ~ , system in accordance with the present invention;
FIGURE 7 is a side view partly in cross section of the dowrlhole acoustic tool ofthe acoustic ~ system of FIGURE 6;
F~GURE 8 is a schematic block diagram of the downhole acoustic tool of FIGURE 7;
FIGURE 9 is a schematic block diagram of the surface system of the acoustic 1 system of FIGUR~ 6;
FIGURE 10 is a 1i ~ ,~, .., .~ ;~ elevation view of a production well employing 2~ arlacoustic ~ ;.- . systeminaccordancewithanaltemate~,.,l.o.l;-.. ~ .,l ofthe present invention;
FIGURE 11 is a ,1, ~,. ,...., ., -l ;. elevation view of a production well employing an acoustic ~ .. system in accordance with another alternate t~mho-linn~nt of the present invention; and WO96124751 2 1~ 8 7 4 2 3 PCT/US96/01819 FIGURE 12 is a 1;, ~"~", , 1;~ elevation view of a production well employing an acoustic ~ lI system in accordance with still another altemate Pmhorlimrnt of the present invention.
Description ofthP Preferred F",l,..,l",.~ ..l Referring now to FIGURES I and 4, the multiwell/multizone monitoring and control system of the present invention may include a remote central control center 10 which either wirelessly or via telephone wires to a plurality of well platforms 12. It will be alJ~I~ ' that any number of well platforms may be d by the control system of the present invention with three platforms namely, platform 1, platform 2, and platform N being shown in FIGURES I and 4.
Each well platform has associated therewith a plurality of wells 14 which extend from each platform 12 through water 16 to the surface of the oceam floor 18 and then downwardly into formations under the ocean floor. It will be a~ that while offshore platforms 12 have been shown in FIGI 7RE I, the group of wells 14 associated with each platform are analogous to groups of wells positioned together in an area of land; and the present invention therefore is also well suited for control of land based wells.
As mentioned, each platform 12 is associated with a plurality of wells 14. For purposes of illustration, three wells are depicted as being associated with platform number I with each well being identified as well number 1, well number 2 and well number N. As is known, a given well may be divided into a plurality of separate zones which are required to isolate specific areas of a well for purposes of producing selected fluids, preventing blowouts and preventing water intake. Such zones may be positioned in a single vertical well such as well 19 associated with platform 2 shown in FlGURE 1 or such ~ones can result when multiple wells are linlced or otherwise joined together. A }Ja~ .ulal Iy significant . ~ r~ l y feature of well production is the drilling and completion of lateral or branch wells which extend from a particular primary wellbore. These lateral or branch wells can be completed such that each lateral well constitutes a separable zone and can be isolated for selected production. A more Wo 96124751 ~ ~ 8 ~ 4 2 3 PCTIUS96101819 complete description of wellbores containing one or more laterals (known as mllltil I ) can be found in U.S. Patent Nos. 4,807,407, 5,325,924 and U.S.
Application Se}ial 08/187,277 (now U.S. Patent No. ), all of the contents ofeachofthosepatentsandarrli~tinnsbeingi~ lhereinbyreference.
With reference to FrGURr~ S 1-4, each of the we~ls I, 2 and 3 associated with platform 1 include a plurality of zones which need to be monitored and/or controlled for efficient production and l . l~ of the well rduids. For example, with reference to FrGURr~ 2, well number 2 includes three zones, namely zone number 1, zone number 2 and zone number N. Each of zones 1, 2 and N have been completed ina known manner; and more particularly have been completed in the manner disclosed in ~u.~ Application Serial No. 08/187,277. Zone number I has been completed using a known slotted liner ~nmrll~tinn, zone number 2 has been completed using an open hole selective completion and zone number N has been completed using a cased hole selective completion with sliding sleeves. Associated with each of zones 1, 2 and N is a downhole control system 22. Similarly, associated witb each wellplatform 1. 2 and N is a surface control system 24.
As discussed, the multiwell/multizone control system of the present invention iscomprised of multiple dowrlhole electronically controlled el~ , .1,"";..~1 devices and multiple computer based surface systems operated form multiple locations.
An important function of these systems is to predict the future flow profile of multiple wells and monitor and control the fluid or gas flow from the formation into the wellbore and from the wellbore into the surface. The system is also capable of receiving and l . ", .~. " i l l; l .o data from multiple locations such as inside the borehole, and to or from otber platforms I, 2 or N or from a location away from any well site such as central control center 10.
The dov~nhole control systems 22 will interface to the surface system 24 using awireless .. ,.. ,.,."1 ~linn System or through an electrical wire (i.e., hardwired) connection. Tlle downhole systems in the wellbore can transmit and receive data and/or commands to or from the surface andlor to or from other devices in the borehole. Referrln~ now to FrGURr. 5, the surface system 24 is composed of a WO96/24751 PCrll~ss6101819 computer system 30 used for processing, storing and displaying the; " r." " ,~ 1 ;. ", acquired downhole and interfacing with the operator. Computer system 30 may be comprised of a personal computer or a work station with a processor board, short term and long term storage media, video amd sound capabilities as is well know. Computer control 30 is powered by power source 32 for providing energy necessary to operate the surface system 24 as well as any downhole system 22 if the interface is a.~.. ." ~1,l;~1, .1 using a wire or cable. Power will be regulated and converted to the appropriate values required to operate any surface sensors (as well as a downhole system if a wire connection between surface amd downhole is available).
A surface to borehole transceiver 34 is used for sending data downhole and for receiving the infr~rrn~tir n transmitted from inside the wellbore to the surface. The transceiver converts the pulses received from dowrlhole into signals compatible with the surface computer system and converts signals from the computer 30 to an appropriate i nn~ means for ... " . . . " ". ,~ downhole to downhole control 15 system22. C~,.,.. ,.~, -';,."~downholemaybeeffectedbyavarietyofknownmethodsincluding hardwiring and wireless 1 .. l. l .. l l: -~ ;-,. ,~ techniques. A preferred technique transmits acoustic signals down a tubing string such as production tubing string 38 (see FIGURE 2) or coiled tubing. Acoustical 1 . ,, . . ", . ", :. ,. I ir~n may include variations of signal frequencies, specific frequencies. or codes or acoustical signals or rl .. "1,;" ~l ;rl"~
of these. The acoustical ~ media may include the tubing string as illustrated in U.S. Patent Nos. 4,3 75,239; 4,347,900 or 4,378,850, all of which are herein by reference. Alternatively, the acoustical ~ " may be transmitted through the casing stream, electrical line, slick line, ~ " ,, soil aroumd the well, tubing fluid or annulus fluid. The 1 l ,.. ,~. . l ;~;. ., . medium where the acoustic signal will travel in the borehole can be production tubing or coil tubing.
Referring to FIGURE 6, a production well (i.e., completed well) 110 enclosed by a casing 112 with a rig 114 at the surface is generally shown, such being well known in the art. Production tubing 116 is installed in well 110, also as is well known. The lower end of production tubing 116 is perforated to provide a path for the flow of oil 30 from the ll~d~U~ JII bed up the center of the production tubing. A packer 118 is wos6/247sl Pcrluss6lol8ls provided to isolate this lower end from the upper portion of the well. Sensors 120 are provided to monitor downhole parameters (such as pressure, ~ aluu~, flow, gas influx, etc.) amd el.~,LI. ., . ~ I devices 122 include, e.g., a sliding sleeve or packer, a valve or pump or other fluid flow devices for control. Such sensors and/or f l~,i" ", ,~ devices may be mounted downhole in the production well itself amd/or ill-,Ul~ into the production tubing, as are well known. A downhole acoustic ~. ., . " . " . :~ l ;r~ . tool 124 in accordance with the present invention is provided for acoustic telemetry. Acoustic tool 124 is constructed to operate over depths,pressures and t~ laluuc~ commonly found in a downhole ~.IVilUl~ll.llL. An upholeacoustic~.. ,.. ; -';~.l~tool125isprovidedforacousticallyf~l.".".. ;. l;,.~with downhole tool 124, and may a similar type tool.
Referring to FIGURE ~, acoustic tool 124 comprises a cylindrical mandrel 126 having a male rotary connection 128 at one end thereof and a female rotary coMection 130 at the other end thereof. Tool 124, when installed in a production well, becomes part ofthe production tubing 116. An opening or channel 132 extends It~n~itll~lin~lly through mandrel 126 permining flow of oil or gas Lll~ Lluuu~ll. Mandrel 1 26 includes a plurality of machined cavities 134 and 136 wherein the ~ of the tool are housed. A~ lf~ ceramictransducer(ie~astackoflll ~llr~ elements)l38 is mounted in cavity 134 in a ( omrrPccPd state and in intimate contact with the mandrel for acoustic coupling therewith. Transformer coils 140, an electronic assembly (i.e., a printed circuit board) 142 and a battery pack assembly (preferably a pair of battery packs) 144 are mounted in cavity 136. It will be appreciated that the above described all,.,.,..,.~ isonlyexemplaryandthe~ ofthetoolcanbehousedinany number of cavities, e.g., each component could be mounted in a separate cavity. In the present example, coils 140 and circuit board 142 are coMected to transducer 138 by wires that pass through a paa~a~wa~r (not shown) in the mandrel. Transformer coils 140, circuit board 142 and battery packs 144 are i~L~,U~u~ d by wires (not shown) in cavity 136, and are connected to other tools in the production tubing by means of coMectors 146 which are hard wired to the other tools through ua~ag~ay~, such being well known in the art, see, e.g., U.S. Patent No. 5,144,126, entitled Apparatus WO 96/24751 2 1 8 ~ ~ ~ 3 Pcr~usg6/~)l8l9 g For Nuclear Logging Employing Sub Wall Moumted Detectors and Electronics and Modular Connector Assemblies, assigned to the assignee hereof and which is expressly i--cul~,uldt~,il herein by reference. Further, other means of j~-t ~C~ tools, asmany are well known, may be employed. A sleeve 148 is connected onto mandrel 126byarotaryconnectionl51. Sleevel48coverscavitiesl34andl36. ApluralityofO-rings 150 are moumted within co~ u~ lg recesses in mandrel 126 and provide a seal between sleeve 148 and mandrel 126, thereby protecting the ~ of the tool from the harsh downhole ~llVilUIIIII~ . A locking ring 152 attached at rotary connection 153 and a shoulder sub 154 are provided to secure sleeve 148 on mandrel 126. Mamdrel 126 if disposed downhole in a production string without sleeve 148 would subject the mandrel to high stresses, whereby stack 138 therein would be unloaded or over loaded resulting in poor acoustic coupling. Sleeve 148, by way of ~A onnArti-~nc 151 and 153, absorbs much of these stress, whereby proper loading on the stack is The 1~ . stack 138 may be comprises of any of several known materials including ~ rlr~ crystalline materials or a suitable f lluCI~,~LI;-, ceramic material such as lead zirconium titanate (PZT). Such known materials generate anelectrical signal once a mechanical force such as vibration or stress is e~erted onto the stack amd exert a mechanical force when an electrical signal is applied to the stack.
Battery pack assembly 144 preferably comprises a dual battery pack which may be connected in series or parallel or one of the packs provides the downhole electrical power while the other pack is being recharged. The battery described herein is preferably a battery that has the ability to operate at high t~ .laL~ (above 175 ~ C), has a long operating life (as much as five years), is small in size (for example sized or otherwise adapted to fit within an envelope of 1 " in diameter), has the ability for continuous discharge for illaLI ulll~l. aiiull in Ill;~lù~JlU~ Ul~l (1 0 milliamperes), has the ability for periodic discharge for ~.- -, . " ., ....; A I ;~Alng equipment (15 milliamperes per minute at 2% duty cycle), has the ability for a minimum of 100 recharging cycles from external power sources as a generator, and includes high energy density and excellent 3 0 self-discharge .1,, ~ Preferably, the battery comprises a solid lithium-metal WO 96/247!; L PCI'/US96/01819 2~ 87 423 polymer eleetrolyte secondaly battery of the type deseribed in the paper entitled "Large Lithium Polymer Battery D~ lv,u~ Ahe Immobile Solvent Coneept", M. Gauthier et al, the entire eontents of whieh is; ~ ;l herein by reference. Batteries of this typearealsodiselosedinU.S.PatentNos.4,357,401;4,578,326and4,758,483allof the contents of which are i., .1,. ~ herein by reference. It is believed that such lithium polymer battery cells are preferred over other battery technology such as nickel cadmium or lead acid due to the higher energy density, smaller size and better self discharge . .11~ of the lithium polymer batteries. Still another battery whieh is believed to be espeeially useful in the present invention are those 1.~ r batteries available from Duraeell Ine. of Bethel, Conneetieut whieh ineorporate therein anintegrated eireuit ehip for extending and or optimizing the battery life, providing high energy density, high power and a wide t~,lll,U.,I~Lul~ rAAnge for 1, r.", I~ Sueh batteries are sold by Duraeell Ine. under the trade names DR15, DR17, DR3v, DR35and DR36 Referring to FIGURE 8, the eleetronies assembly eomprises a data aequisition and eontrol eireuit 160 whieh pre-proeesses data from the sensors 120, digitizes the pre-proeessed data~ and proeess the data for I~ to the surfaee. rhe data aequisition and eontrol eireuit 160 is preferably a IIIII~IVVIU~ UI based system (e.g.
3 ~ KHz based processor system). Further, by way of example, the data acquisition circuit satisfies tbe following A~r~rifirAtir,nq sample rate, 100 samples per second;
channels~ 8 analog channels and l frequency channel; and power ~ l ;r~ l o milliamps ~ 5V. lAhe electronics assembly preferably includes nonvolatile memory(e.g., 64 KB) and I MB of RAM memory for storage of downhole software and the aequired data in the production well. Data signals to be transmitted to the surface are transmitted via aeoustic telemetry (which includes both pulse mode and continuous wave 1,, ,~1 l l:.... ", schemes). Acoustic telemetry is preferably at a data baud rate of at least 0.5 bits per second. A signal for I ~ I is stepped up in voltage by a step up voltage regulator 162 and the Ll_l~rullll~l to a voltage sufficient to cause the staek to induce an aeoustic signal (e.g., an elastic wave which has an extensional motion along the axis of the production tubing/mandrel) in the mandrel which permeates uphole wo 96n47sl 2 1 8 7 4 2 3 p~rn~s96lol8l9 -Il-through the production tubing where it is detected at the surface. It will be a~
that the batteries cam be comnected in series to increase the operating voltage or in parallel to provide a greater drive current. By way of example, 200 milliamps ~ 50V
is required to drive the tr msducer.
The stack 138 is also used for receiving acoustic data signals transmitted from the surface! whereby an acoustic signal (e.g., am elastic wave which has am extensional motion along the axis of the production tubing) which permeates downhole through the production tubing and imparts stresses and tension on the stack resulting in an electronic signal. This signal is amplified by an amplifier 166 and then processed by the data acquisition and control circuit 160 to request i " r( " ", .1 ;"" and/or to generate command/control signals for the sensors 120 amd the ~ devices 122. It will be appreciated that the entire stack may not be required for receiving acoustic signals.
Referring to FIGURE 9, at the surface, a computer 170 (e.g.. a personal computer having 2 seriall I parallel port, 8 MBytes of RAM and 250 MB of disk space) loaded with software and data acquisition and processing downhole modules 172 are employed. The software performs the control functions required for the transfer of dat3 from the data acquisition module to the processoFmodule and perfomms the data processing and ba.,h~lulld routines to assure that all tasks are executed in the proper priority sequence (e.g., decoding, display, and storage). Further, by way of example, the data acquisition module satisfies the following ~rerifir~til~nc sample rate, I Kilo samples per second; channels, 8 analog channels, 4 digital channels and I frequency cha}mel; and power roncllnnrtion 1 0 milliamps ~ 5V. Surface. The software will also control the data exchange between the system and the operator (e.g., entering of the proper data processing parameters into the computer by the operator). The data acquisition and processing downhole modules 172 acquire the acoustic data transmitted from do~nhole using an acoustic transceiver 174, process the received data, utilizes the infrrrn~tinntocontroloperationoftheproductionwell,andlordisplaytheil,r~".,.,.li..., to an operator at the surface or platform. The data acquisition and processing downhole modules 172 also generates command signals which are transmitted Wo 96/24751 pcrNs96lol8l9 2~ 8~?~ --downhole by acoustic transducer 174. Surface equipment further includes a phone or satellite based modem (e.g., a modem having a baud rate of 28.4 KBits per second) for Llallal.,~ data between the production well site and a remote facility using phone lines, and/or satellite ~,. ." . ", . .. ,;. .A. ;nn It will be appreciated that the use of the production tubing itself as the medium for acoustic telemetry is an import~mt feature of the present invention.
The downhole acoustic telemetry of the present invention provides mamy features and advantages relative to the prior art. An important feature and advantage is that the present invention provides no ob~L u~,Liull~ within the production tubing. 'IAhat is, the present invention provides acoustic telemetry while ~; l " "l ~ ", ~ A; "; "g production tubing obstruction free such that devices including coil tubing may be delivered through the production tubing without interruption. Further, while two-way acoustic . . ."" ", ...: Al ;. ", is described above, one-way ~, . .. : Al ir~n made be employed.
Referring to FIGURE 10, a production well (i.e., completed well) 110' enclosed by a casing 112' with a rig 114' at the surface is generally shown, such being well known in the art. Production tubing 116' is installed in well 110', also as is well known. The lower end of production tubing 1 16' is perforated to provide a path for the flow of oil from the ll.ydlu~,_bull bed up the center of the production tubing. A packer 118' is provided to isolate this lower end from the upper portion of the well. Sensors 120' are provided to monitor downhole parameters (such as pressure. ~ u~l~Lul~, flow, gas influx, etc.) and elc~,LI~ devices 122' include, e.g., a sliding sleeve or packer, a valve or pump or other fluid flow devices for control. A coil tubing 200 is extended down the opening of the production tubing as is well known in the art. An uphole acoustic tool 202 (e.g., an acoustic receiver, for example, an ~c.,CI.,lu~ ,L~l) and a downhole acoustic tool 204 (e.g., an acoustic transmitter, for example a 1~ . l, ;c device) are provided on coil tubing 200 for acoustic telemetry in accordance with this alternate l mhol1im~ nt lt will be appreciated that two-way acoustic ... ,.. " ", ... ;~ Al ;on is within the scope of the present invention, e.g., ri~ 7nrl~ctrir tl~la~ uphole and downhole. It will further be appreciated that coil tubing is also employed while drilling wo 96124751 ~Cr/US96JD1819 2~

a borehole, and acoustic telemetry as described herein may be applied such coil tubing.
Also, the acoustic telemetly of the present invention, as applied to coil tubing, may be applied to other continuous tubing strings, e.g., chemical injection tubing, a dewatering string and the like. Sensors 206 are also provided downhole on coil tubing 200 or in the production well or production tubing, as is also well known in the art. Sensors 206 are connected to acoustic tool 204 for telemetry uphole.
As described in the earlier embodiment, at the surface a computer loaded with software and a data acquisition and processing downhole modules are employed. The software performs the control functions required for the transfer of data from the data acquisition module to the processor module and performs the data processing and v~k~uvl~d routines to assure that all tasks are executed in the proper priority sequence (e.g., decoding, display, and storage). Surface equipment further includes a phone or satellite based modem for ila ~ data between the production well site and a remote facility using phone lines, and/or satellite ~ ~ .., .., .., ., :. -: ;. " .
The use of the coil tubing itself as the medium for acoustic telemetry is an important feature of the present invention.
Referring to FIGURE 11, a production well (i.e., completed well) 110" enclosed by a casing 112" with a rig 114" at the surface is generally shown, such being well known in the art. Production tubing 116" is installed in well I 10", also as is well known. The lower end of production tubing 116" is perforated to provide a path for the flow of oil from the lIrVIV~aIbVI1 bed up the center of the production tubing. A packer 118" is provided to isolate this lower end from the upper portion of the well. Sensors 120" are provided to monitor downhole parameters (such as pressure, t~ ,u~la~
flow, gas influx, etc.) and elc ~ ,; rl devices 122" include, e.g., a sliding sleeve or packer, a valve or pump or other fluid flow devices for control. Such sensors and/or clc~ .f.. 1~ devices may be mounted downhole irl the production well itself and/or ill~,vl,uula~v into the production tubing, as are well known. A downhole acoustic ..., ., .. " ... ;. ~ .. tool 220 in accordance with an altemate embodiment of the present invention is provided for acoustic telemetry. Acoustic tool 220 is integral to casing 112" and is constructed to operate over depths, pressures and l~ a~

? 1 87 423 commonlyfound inadownhole CllV;IUIIII.,II~. Acoustictool 220 similarto tool 124 (FIGURE 7) with the exception that the rotary ..,." ~;..,.c are attached to the casing whereby the tool forms a part of the casing with the opening Ill~lcLLIuu~;ll forming part ofthe completed well. An uphole acoustic ~...""""~; .-:;".. tûol 221 is provided for acoustically ~ with downhole tool 220, and may a similar tyype tool.
The use of the casing itself as the medium for acoustic telemetry is am important feature of the present invention.
Referring to FIGURE 12, a production well (i.e., completed well) 110"' enclosed by a casing 112"' with a rig 114"' at the surface is generally shown, such being well known in the art. Production tubing 116"' is installed in well 110"', also as is well known. The lower end of production tubing 116"' is perforated to provide a path for the flow of oil from the lly~Lucall)ull bed up the center of the production tubing. A packer 118"' is provided to isolate this lûwer end from the upper portion of the well. Sensors 120"' are provided to monitor downhole parameters (such as pressure, ~lllp~a~ul~, flow, gas influx, etc.) and ~IC~L~ devices 122"' include, e.g., a sliding sleeve or packer, a valve or pump or otber fluid flow devices for control. Such sensors and/or ~1~.,1.~.". l, , l devices may be mounted downhole in tbe production well itself and/or incorporated into the production tubing, as are well known. A downhole acoustic ~ "", ~ " tool 222 in accordance with an alternate rllli,ù,l;.ll. .. 1 ofthe present inventiûn is provided for acoustic telemetry. Acoustic tool 222 is coupled to casing 112" ', coupling of tools to the casing being well known in the art, and is constructed depths, pressures and ~ la~uuc~ commonly found in a downhole ~1l vilullulcllL. Acoustic tool 222 is similar to tool 24 (FIGURE 7) with the exception of the coupling to the casing whereby the opening through the tool forming 2~ part ofthe completed well. An uphole acoustic . . ."",,.. ,;. ~1;.,,, tool 223 is provided for acoustically ~ . " " " " ~ with downhole tool 222, and may a similar type tool.
The use of the casing itself as the medium for acoustic telemetry is an important feature of the present invention.

Wo 96124751 2 1 8 7 4 2 3 PCr/USs6JD18~9 - While preferred l~mhotiim~ntc have been shown and described, various ~r~iifir:lti~nc and ~llhctitllfir,nc may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the presentinvention has been described by way of illllct~firnc and not limitation.
What is claimed is:

Claims

CLAIM 1 . In a production well for producing petroleum fluids. the production well including production tubing running from the surface downhole to a production zone, the improvement comprising:
a downhole acoustic communication device for transmitting or receiving acoustic signals using a plurality of longitudinal element in a production well as the transmission medium.
CLAIM 2. The production well of claim 1 wherein said plurality of longitudinal elements comprise production tubing.
CLAIM 3 . The production well of claim 1 wherein said plurality of longitudinal elements comprise production well casing.
CLAIM 4. The production well of claim 1 wherein said acoustic transceiver comprises:
a stack of piezoelectric elements.
CLAIM 5. The production well of claim 4 wherein said acoustic device comprises:
a processing circuit for generating transmit electrical signals for driving saidpiezoelectric elements and for processing receive electrical signals generated by said piezoelectric elements to receive acoustic signals.
CLAIM 6. The production well of claim 5 wherein said processing circuitcomprises:
a data acquisition and control circuit for processing data or commands to be transmitted and generating said transmit electrical signals;
a step up voltage regulator for stepping up the voltage of said transmit electrical signals to generate stepped up transmit electrical signals and applying said stepped up electrical voltage signals to said piezoelectric elements; and a voltage amplifier for amplifying said receive electric signals and presenting said receive electric signals to said data acquisition and control circuit for processing data or commands received.
CLAIM 7. The production well of claim 6 wherein said data acquisition and control circuit comprises microprocessor.
CLAIM 8. A production well for producing petroleum fluids comprising:
production tubing running from the surface downhole to a production zone;
at least one downhole sensor associated with said production tubing or said production well;
a downhole acoustic device for transmitting or receiving acoustic signals using the production tubing as the transmission medium, said downhole acoustic device in communication with said downhole sensor; and an uphole acoustic device for transmitting or receiving acoustic signals associated with said downhole acoustic device using the production tubing as thetransmission medium.
CLAIM 9. The production well of claim 8 wherein:
said downhole acoustic device comprises a downhole processing circuit for generating downhole transmit electrical signals in response to signals received from said downhole sensor, said downhole transmit electrical signals for driving saiddownhole acoustic device, said downhole processing circuit for processing downhole receive electrical signals generated by said downhole acoustic device from received acoustic signals, said downhole receive electrical signals presented to said downhole sensor, and said uphole acoustic device comprises an uphole processing circuit for generating uphole transmit electrical signals, said uphole transmit electrical signals for driving said uphole acoustic device, said uphole processing circuit for processing uphole receive electrical signals generated by said uphole acoustic device from received acoustic signals.
CLAIM 10. The production well of claim 9 wherein:
said downhole processing circuit comprises, a data acquisition and control circuit for processing data or commands from saiddownhole sensor to generate said downhole transmit electrical signals, a step up voltage regulator for stepping up the voltage of said downhole transmit electrical signals to generate stepped up transmit electrical signals and applying said stepped up electrical voltage signals to said downhole acoustic device, and a voltage amplifier for amplifying said receive electrical signals and presenting said receive electric signals to said data acquisition and control circuit for processing data or commands received at said downhole acoustic device; and said uphole processing circuit comprises, a data acquisition and processing circuit receptive to said uphole receive electrical signals for processing data or commands received, and a computer having memory for storing programs for processing data commands from said data acquisition and processing circuit, said computer for generating data or commands to be processed by said data acquisition and processing circuit for generating said uphole transmit electrical signals.
CLAIM 11. The production well of claim 10 wherein said data acquisition and control circuit comprises a microprocessor.
CLAIM 12. An acoustic tool for use with production tubing comprising:
a mandrel having at least one cavity formed therein, said mandrel having an opening longitudinally and having opposing ends for connection to said production tubing, whereby said acoustic tool forms part of said production tubing;
a piezoelectric transducer disposed within said at least one cavity wherein acoustic signals are coupled between said transducer and said mandrel;
an electronic assembly disposed within said at least one cavity for interfacing with said piezoelectric transducer; and a sleeve disposed on said mandrel for covering said at least one cavity.
CLAIM 13. The acoustic tool of claim 12 further comprising a battery pack disposed within said at least one cavity, said battery pack connected to said electronic assembly.
CLAIM 14. The acoustic tool of claim is further comprising:
transformer coils disposed within said at least one cavity and connected to saidpiezoelectric transducer.
CLAIM 15. The acoustic tool of claim 12 further comprising:
a connector for electrically connecting said acoustic tool with another device.
CLAIM 16. The acoustic tool of claim 12 wherein said at least one cavity comprises:
first and second cavities with said piezoelectric transducer disposed in said first cavity and said electronic assembly disposed in said second cavity.
CLAIM 17. The acoustic tool of claim 12 further comprising:
a seal between said sleeve and said mandrel.
CLAIM 18. The acoustic tool of claim 17 wherein said seal comprises:
a plurality of O-rings.
CLAIM 19. The acoustic tool of claim 12 wherein said piezoelectric transducer comprises:
a stack of piezoelectric elements,
CLAIM 20. The acoustic tool of claim 19 wherein said piezoelectric elements are comprised of ferroelectric ceramic material.
CLAIM 21. A production well for producing petroleum fluids comprising:
casing running from the surface downhole to a production zone;
at least one downhole sensor associated with said casing;
a downhole acoustic device for transmitting or receiving acoustic signals using the casing as the transmission medium, said downhole acoustic device in communication with said downhole sensor; and an uphole acoustic device for transmitting or receiving acoustic signals associated with said downhole acoustic device using the casing as the transmission medium.
CLAIM 22. The production well of claim 21 wherein:
said downhole acoustic device comprises a downhole processing circuit for generating downhole transmit electrical signals in response to signals received from said downhole sensor, said downhole transmit electrical signals for driving saiddownhole acoustic device, said downhole processing circuit for processing downhole receive electrical signals generated by said downhole acoustic device from received acoustic signals, said downhole receive electrical signals presented to said downhole sensor; and said uphole acoustic device comprises an uphole processing circuit for generating uphole transmit electrical signals, said uphole transmit electrical signals for driving said uphole acoustic device, said uphole processing circuit for processing uphole receive electrical signals generated by said uphole acoustic device from received acoustic signals.
CLAIM 23. The production well of claim 22 wherein:
said downhole processing circuit comprises, a data acquisition and control circuit for processing data or commands from saiddownhole sensor to generate said downhole transmit electrical signals, a step up voltage regulator for stepping up the voltage of said downhole transmit electrical signals to generate stepped up transmit electrical signals and applying said stepped up electrical voltage signals to said downhole acoustic device, and a voltage amplifier for amplifying said receive electrical signals and presenting said receive electric signals to said data acquisition and control circuit for processing data or commands received at said downhole acoustic device; and said uphole processing circuit comprises, a data acquisition and processing circuit receptive to said uphole receive electrical signals for processing data or commands received, and a computer having memory for storing programs for processing data commands from said data acquisition and processing circuit, said computer for generating data or commands to be processed by said data acquisition and processing circuit for generating said uphole transmit electrical signals.
CLAIM 24. The production well of claim 23 wherein said data acquisition and control circuit comprises a microprocessor.
CLAIM 25. An acoustic tool for use with production well casing comprising:
a mandrel having at least one cavity formed therein, said mandrel having an opening longitudinally therethrough and associated with said casing;
a piezoelectric transducer disposed within said at least one cavity wherein acoustic signals are coupled between said transducer and said mandrel;
an electronic assembly disposed within said at least one cavity for interfacing with said piezoelectric transducer; and a sleeve disposed on said mandrel for covering said at least one cavity.
CLAIM 26. The acoustic tool of claim 25 wherein said mandrel is connected to said casing to be integral therewith.
CLAIM 27. The acoustic tool of claim 25 wherein said mandrel is coupled to said casing.
CLAIM 28. The acoustic tool of claim 25 further comprising:
a battery pack disposed within said at least one cavity, said battery pack connected to said electronic assembly.
CLAIM 29. The acoustic tool of claim 25 further comprising:
transformer coils disposed within said at least one cavity and connected to saidpiezoelectric transducer.
CLAIM 30. The acoustic tool of claim 25 further comprising:
a connector for electrically connecting said acoustic tool with another device.
CLAIM 31. The acoustic tool of claim 25 wherein said at least one cavity comprises:
first and second cavities with said piezoelectric transducer disposed in said first cavity and said electronic assembly disposed in said second cavity.
CLAIM 32. The acoustic tool of claim 25 further comprising:
a seal between said sleeve and said mandrel.
CLAIM 33. The acoustic tool of claim 32 wherein said seal comprises:
a plurality of O-rings.
CLAIM 34. The acoustic tool of claim 25 wherein said piezoelectric transducercomprises:
a stack of piezoelectric elements,
CLAIM 35. The acoustic tool of claim 34 wherein said piezoelectric elements are comprised of ferroelectric ceramic material.
CLAIM 36. In a well, the well including continuous tubing running from the surface downhole, the improvement comprising:
a downhole acoustic communication device for transmitting or receiving acoustic signals using the continuous tubing as the transmission medium.
CLAIM 37. The well of claim 36 wherein said continuous tubing comprises coil tubing.
CLAIM 38. The well of claim 36 wherein said continuous tubing comprises chemical injection tubing.
CLAIM 39. The well of claim 36 wherein said continuous tubing comprises dewatering tubing.
CLAIM 40. The production well of claim 36 wherein said acoustic device comprisesa stack of piezoelectric elements.
CLAIM 41. The production well of claim 36 wherein said acoustic device comprisesan accelerometer.