OA11891A - Method and system for performing operations and for improving production in wells. - Google Patents

Abstract

A method for performing operations and for improving production in a well includes the steps of: providing radio identification devices (72) at known locations in the well, and providing a reader device (70) configured to read the identification devices, and to control the operations responsive to signals from the identification devices. The method also includes the steps of providing a process tool (68), and transporting the process tool and the reader device through the well. The reader device is programmed to control the process tool upon reception of a response signal from a selected identification device. The method can be used to perform perforating processes, packer setting processes, bridge plug setting processes, logging processes, inspection processes, chemical treating processes, and cleaning processes. In addition, the method can be performed dynamically by controlling the tool as it moves through the well, or statically by stopping the tool at a particular location within the well. A system for performing the method includes the identification devices, the reader device, the process tool, and a computer or controller. In addition, the identification devices can be placed in casing collars of the well and can be configured as passive devices or as active devices.

Description

Cross Reference to Related Applications ι i U w |

This application is a continuation-in-part of patentapplication serial no. 09/286,650, filed April 6, 1999, entitled"Method And Apparatus For Determining Position In A Pipe".

Field of the Invention

This invention relates to generally to wells used in theproduction of fluids such as oil and gas. More, specifically, thisinvention relates to a method and System for performing variousoperations and for improving production in wells.

Background of the Invention

Different operations are performed during the drilling andcompletion of a subterranean welf, and also during the productionof fluids from subterranean formations via the completed well.For example, different downhole operations are typicallyperformed at some depth within the well, but are controlied atthe surface. A perforating process is one type of downhole operationthat is used to perforate a well casing. A conventionalperforating process is performed by placing a perforating tool(i.e., perforating gun) in a well casing, along a section of thecasing proximate to a geological formation of interest. Theperforating tool carries shaped charges that are detonated using asignal transmitted from the surface to the charges. Détonationof the charges créâtes openings in the casing and concrète aroundthe casing, which are then used to establish fluid communicationbetween the geological formation, and the inside diameter of thecasing.

Another example of a downhole operation is the setting ofpackers within the well casing to isolate a particular section ofthe well or a particular geological formation. In this case, apacker can be placed within the well casing at a desired depth,and then set by a setting tool actuated from the surface. Otherexemplary downhole operations include the placement of loggingtools at a particular geological formation or depth within thewell casing, and the placement of bridge plugs, casing patches,tubulars, and associated tools in the well casing. 118 9 1

One critical aspect of any downhole operation involvesascertaining the depth in the well where the operation is to beperformed. The depth is typically ascertained using well logs. Aconventiona) well log includes continuous readings from a logginginstrument, and an axis which représente the well depths atwhich the readings were obtained. The instrument readingsmeasure rock characteristi.es such as naturel gamma rayradiation, electrical resistivity, density and acoustic properties.Using these rock characteristics geological formations ofinterest within the well, such as oil and gas bearing formations,can be identified. The well is initially logged "open hole" whichbecomes the bench mark for ail future logs. After the well iscased, a cased hole log is then prepared and correlated, or "tiedin", to the open hole log.

Using the logs and a positioning mechanism, such as a wireline or coiled tubing, coupled to an odometer, a tool can be placedat a desired depth within the weil, and then actuated as requiredto perform the downhole operation. One problem withconventional logging and positioning techniques is that it isdifficult to accurately identify the depth of the tool, and tocorrelate the depth to the open hole logs.

Figure 1 illustrâtes a prior art perforating process beingperformed in an oil and gas well 10. The well 10 includes a wellbore 12, and a casing 14 within the well bore 12 surrounded byconcrète 16. The well 10 extends from an earthen surface 18through geological formations within the earth, which arerepresented as Zones A, B and C. The casing 14 is formed bytubular éléments, such as pipe or tubing sections, connected toone another by collars 20. In this example the tubular élémentsthat form the casing 14 are about 40 feet long so that the casingcollars 20 are forty feet apart. However, tubular éléments withshorter lengths (e.g., twenty feet) can be interspersed with theforty feet lengths to aid in depth déterminations. Thus in Figure1 two of the casing collars 20 are only twenty feet apart.

For performing the perforating operation a perforating tool22 has been lowered into.the casing 14 on a wire line 24. A mast26 and pulleys 28 support the wire line 24, and a wire line unit30 Controls the wire line 24. The wire line unit 30 includes a 3 113» p drive mechanism 32 that lowers the wire line 24 and the tool 22into the well 10, and raises the wire line 24 and the tool 22 outof the well 10 at the completion of the process. The wire lineunit 30 also includes an odometer 34 that measures the unwoundlength of the wire line 24 as it is lowered into the well 10, andequates this measurement to the depth of the tool 22 within thewell.

During formation of the well 10 an open hole log 36 wasprepared. The open hole log 36 includes various instrumentreadings, such as gamma ray readings 38 and spontaneouspotential (SP) readings 40 which are plotted as a function ofdepth in feet. For simplicity only a portion of the open hole log36, from about 7000 feet to about 7220 feet, is illustrated.However, in actual practice the entire well 10 from the surface18 to the bottom of the well 10 may be logged. The open hole log36 permits skilled artisans to ascertain the oil and gascontaining formations within the well 10 and the most productiveintervals of those formations. For example, based on the gammaray readings 38 and the SP readings 40 it is determined that ZoneA may contain oil and gas reserves. It is thus desired toperforate the casing 14 along a section thereof proximate to Zone A.

In addition to the open hole log 36, following casing of thewell 10, cased hole gamma ray readings 44 are made, and a casingcollar log 42 can be prepared. The casing collar log 42 is aisoreferred to as a PDC log (perforating depth control log). Thecasing collar log 42 can be used to identify the section of thecasing 14 proximate to Zone A where the perforations are to bemade.

Using techniques and equipment that are known in the art,the casing collar log 42 can be accurately correlated, or "tied in”,to the open hole log 36. However, using conventional positioningmechanisms, such as the wire line unit 30, it may be difficult toaccurately place the perforating tool 22 at the required depthwithin the well. For example, factors such as stretching,élongation from thermal effects, sinusoïdal and helical buckling,and deformation of the wire line 24 can affect the odometerreadings, and the accuracy of the odometer readings relative tothe open hole odometer readings. 4 .* “ — Λ ι ι » » 1

Thus, as shown in Figure 1, the odometer readings whichindicate the depth of the perforating tool 22, may not equate tothe actual depths, as reflected in the open hole log 36 and thecasing collar log 42 . In this example, the odometer readings 5 differ from the depths identified in the open hole log 36 and thecasing collar log 42 by about 40 feet. With this situation, whenthe perforating tool 22 is fired, the section of casing 20proximate to Zone A may be only partially perforated, or notperforated at ail. 10 Because of these tool positioning inaccuracies, various corrélative joint logging and wire logging techniques hâve beendeveloped in the art. For example, one prior art technique useselectronic joint sensors, and electrically conductive wire line, todétermine joint-to-joint lengths, and to correlate the odometer 15 readings of the wire line to the casing collar log. Although thesecorrélative joint logging and wire line logging techniques areaccurate, they are expensive and time consuming. In particular,additional crews and surface equipment are required, andadditional wire line footage charges are incurred. 20 In addition to tool positioning inaccuracies, computational errors also introduce inaccuracies in depth computations. Forexample, a too, operator can make computational errors bythinking one number (e.g., 7100), while the true number may bedifferent (e.g., 7010). Also, the tool operator may position the 25 tool by compensating a desired amount in the uphole direction,when in reality the downhole direction should hâve been used.These computational errors are compounded by fatigue, theweather, and communication problème at the well site.

It would be désirable to obtain accurate depth readings for 30 downhole tools without the necessity for compticated andexpensive corrélative joint logging and wire logging techniques.

In addition, it would be désirable to control down hole operationsand processes without having to rely on inaccurate depth readingscontaminated by computational errors. The présent invention is 35 directed to an improved method and System for performingoperations and processes in wells, in which the depths of downhole tools are accurately ascertained and used to control theoperations and processes.

1 5

Another limitation of conventions! downhole operations thatare dépendent on depth measurements, is that downhoie toolsmust first be positioned in the well, and then actuated from thesurface. This requires additional time and effort from wellcrews. In addition, surface actuation introduces additionalequipment and variables to the operations. It would beadvantageous to be able to control downhole operations withoutthe requirement of surface actuation of the downhole tools. Withthe présent invention actuation of downhole tools can beperformed in the well at the required depth.

Summary of the Invention

In accordance with the présent invention a method and aSystem for performing various operations in wells, and forimproving production in wells, are provided. Exemplaryoperations that can be performed using the method includeperforating processes, packer setting processes, bridge plugsetting processes, logging processes, inspection processes,Chemical treating processes, casing patch processes, jet cuttingprocesses and cleaning processes. Each of these processes, whenperformed in a well according to the method, improves the welland improves production from the well.

In an illustrative embodiment the method is used to performa perforating process in an oil or gas production well. The wellincludes a well bore, and a well casing, extending from an earthenor subsea surface into various geological zones within the earth.The well casing includes lengths of pipe or tubing joined togetherby casing collars.

The method includes the initial step of providingidentification devices at spaced intervals along the length of thewell casing. The identification devices can comprise active orpassive radio identification devices installed in each casingcollar of the well casing. Each radio identification device isuniquely identified, and its depth, or location, within the well isaccurately ascertained by corrélation to well logs. Similarly,each casing collar is uniquely identified by the radioidentification device contained therein, and a record of the well 6 1 18 i , including the depth of each casing collar and identification deviceis established.

The method also includes the step of providing a readerdevice, and a transport mechanism for moving the reader devicethrough the well casing proximate to the identification devices.In the illustrative embodiment the reader device comprises aradio frequency transmitter and receiver configured to providetransmission signais for réception by the identification devices.The identification devices are configured to receive thetransmission signais, and to transmit response signais back tothe reader device. The transport mechanism for the reader devicecan comprise a wire line, tubulars, coil tubing, a roboticmechanism, a fluid transport mechanism such as a pump or ablower, a free fall arrangement, or a controlled fall arrangementsuch as a parachute.

In addition to transmitting and receiving signais from theidentification devices, the reader device is also configured totransmit control signais for controlling a process tooi, as afonction of the response signais from the identification devices.For exampie, the reader device can control a perforating toolconfigured to perforate the well casing. Specifically, the readerdevice and the perforating tool can be transported togetherthrough the well casing past the identification devices. Inaddition, the reader device can be programmed to transmit thecontrol signal to detonate the perforating tool, upon réception ofa response signal from an identification device located at apredetermined depth or location within the well. Stateddifferently, the reader device can be programmed to control theperforating tool responsive to locating a spécifie identificationdevice.

As other exemples, the reader device can be configured tocontrol setting tools for packers, bridge plugs or casing patches,to control instrument readings from logging tools, and to controljet cutters and similar tools. With the method of the inventionthe true depth of the process tool can be ascertained in real timeby the reader device using response signais from theidentification devices. Accordingly, there is no need to ascertainthe depth of the tool using an odometer, and expensive wire

Jogging techniques. In addition, operator computational errors arereduced because true depth readings can be provided without therequirement of additional computations. Further, for someprocesses, there is no need to transmit signais to the surface, asthe reader device can be programmed to control the process insitu within the well.

However, it is to be understood that the method of theinvention can also be practiced by transmission of the controlsignais from the reader device to a controller or computer at thesurface, and control of the process tool by the controller orcomputer. In addition, control of the process tool can beperformed dynamically as the process tool moves through thewell with the reader device, or statically by stopping the processtool at a required depth. Further, the method of the invention canbe used to control a multi stage process, or to control a toolconfigured to perform multiple processes. For example, acombination packer setting and perforating tool can be configuredto perform packer setting and perforating processes, as afunction of true depth readings obtained using the method of theinvention.

In the illustrative embodiment the System includes theidentification devices installed in casing collars at spacedintervals along the well casing. The identification devicesinclude a programmable element, such as a transceiver chip forreceiving and storing identification information, such as casingcollar and depth désignations. Each identification device can beconfigured as a passive device, an active device having anantenna, or a passive device which can be placed in an activeState by transmission of signais through well fluids.

The System also includes the reader device and the processtool configured for transport through the well casing. In additionto the transmitter and receiver, the reader device includes one ormore programmable memory devices, such as semiconductor chipsconfigured to receive and store information. The reader devicealso includes a power source such as a power line to the surface,or a battery. In addition, the reader device includes a telemetrycircuit for transmitting the control signais, which can be used tocontrol the process tool, and to provide depth and other 8 Λ Ά **!- 1-' 14* information to operators and equipment at the surface. TheSystem can also include a computer configured to receive andprocess the control signais, and to provide and store informationin Visual or other form for well operators and equipment. Further,the system can include a controller configured to process thecontrol signais for controlling the process tool and variousprocess equipment. The controller can be located at the surface,or on the process tool, to provide a self contained System. Also,the system can be transported to a well site in the form of a kit,and then assembled at the well site.

Brief Description of the Drawings

Figure 1 is a schematic diagram of a prior art downholeoperation being performed using well logs and odometer readingsfrom a tool positioning mechanism;

Figure 2 is a flow diagram illustrating steps in the methodof the invention for controlling a perforating process in a well;

Figures 3A and 3B are schematic cross sectional viewsillustrating a system constructed in accordance with theinvention for performing the perforating process;

Figure 3C is an enlarged portion of Figure 3B, taken alongsection line 3C, illustrating a perforating tool of the system;

Figure 3D is an enlarged portion of Figure 3A, taken alongsection line 3D, illustrating a reader device and an identificationdevice of the system;

Figure 3E is an enlarged cross sectional view taken alongsection line 3E of Figure 3D illustrating a portion of the readerdevice;

Figure 3F is a side élévation view of an alternateembodiment active reader device and threaded mounting device;

Figure 4A is an electrical schematic for the system;

Figure 4B is a view of a computer screen for a computer ofthe system;

Figures 5A and 5B are schematic views illustratingexemplary spacer éléments for spacing the reader device of thesystem from the perforating tool of the system; 9 1135 1

Figures 6A-6D are schematic cross sectional viewsillustrating varîous alternate embodiment transport mechanismsfor the system;

Figures 7A and 7B are schematic cross sectiona! viewsillustrating an alternate embodiment system constructed inaccordance with the invention for performing a packer settingprocess in a well;

Figure 7C is an enlarged portion of Figure 7A taken alongsection line 7C illustrating a threaded connection of a tubingstring of the alternate embodiment system; and

Figure 8A-8C are schematic cross sectional viewsillustrating an alternate embodiment multi stage method andsystem of the invention for performing a packer setting and aperforating processes in combination.

Detailed Description of the Preferred Embodiment

Referring to Figure 2, broad steps in a method forcontrolling an operation or process in a subterranean well inaccordance with the invention are illustrated. The method,broadly stated, includes the steps of: A. Providing a process tool. B. Providing a reader device in signal communication withthe process tool. C. Providing a transport mechanism for the process tool andthe reader device. D. Providing spaced identification devices in a well casingreadable by the reader device. E. Uniquely identifying each identification device anddetermining its depth, or location, in the well using well logs. F. Programming the reader device to transmit a controlsignal to the process tool upon réception of a response signalfrom a selected identification device. G. Transporting the process tool and the reader. devicethrough the well casing. H. Reading the identification devices using the readerdevice. io î. Transmitting the control signal to the process tool uponréception of the signal from the selected identification device toactuate the process tool at a selected depth.

Referring to Figures 3A-3D, a System 50 constructed inaccordance with the invention is illustrated. The System 50 isinstalled in a subterranean well 52, such as an oil and gasproduction well. In this embodiment the system 50 is configuredto perform a perforating process in the well 52. The perforatingprocess performed in accordance with the invention provides animproved well 52, and improves production from the well 52.

The well 52 inciudes a weil bore 54, and a well casing 56within the well bore 54 surrounded by concrète 56. The well 52extends from an earthen surface 60 through geological formationswithin the earth, which are represented as Zones E, F and G. Theearthen surface 60 can be the ground, or alternately a structure,such as an oil platform located above water. In the illustrativeembodiment, the well 52 extends generaliy vertically from thesurface 60 through Zones E, F, and G. However, it is to beunderstood that the method can also be practiced on inclinedwells, and on horizontal wells.

The well casing 56 comprises a plurality of tubularéléments 62, such as lengths of métal pipe or tubing, connected toone another by collars 64. The casing 56 inciudes an insidediameter adapted to transmit fluids into, or out of, the well 52,and an outside diameter surrounded by the concrète 58. Thecollars 64 can comprise couplings having female threads adaptedfor mating engagement with male threads on the tubular éléments62. Alternately, the collars 64 can comprise weldable couplingsadapted for welding to the tubular éléments 62.

Also in the illustrative embodiment the casing 56 isillustrated as having the same outside diameter and insidediameter throughout its length. However, it is to be understoodthat the casing 56 can vary in size at different depths in the well52, as would occur by assembling tubulars with differentdiameters. For example, the casing 56 can comprise atelescoping structure in which the size thereof decreases withincreasing depth. 1 1 8 S ΊΊ

Based on an open hole well log (36-Figure 1), or otherinformation, it is determined that Zone F of the well 52 maycontain oil and gas. It is thus desired to perforate the casing 56proximate to Zone F to establish fluid communication betweenZone F, and the inside diameter of the well casing 56.

For performing the perforating process, the System 50includes a perforating tool 68, and a reader device 70 in signalcommunication with the perforating tool 68. The System 50 alsoincludes a plurality of identification devices 72 (Figure 3D)attached to the collars 64 on the casing 56, and readable by thereader device 70. In addition, the System 50 includes a transportmechanism 66W for transporting the perforating tool 68 and thereader device 70 through the well casing 56 to Zone F. If desired,the System 50 can be transported to the well 52 as a kit, and thenassembled at the well 52.

As shown in Figure 3C, the perforating tool 68 includes adetonator 74 (illustrated schematically) and a detonator cord 76in signal communication with the detonator 74. The detonator 74can comprise a commercially available impact or electricaldetonator configured for actuation by a signal from the readerdevice 70. Similarly, the detonator cord 76 can comprise acommercially available component. The detonator 74 and thedetonator cord 76 are configured to generate and appiy athreshold detonating energy to initiate a détonation sequence ofthe perforating tool 68. In the illustrative embodiment, thedetonator 74 is located on, or within, the perforating tool 68.

As shown in Figure 3C, the perforating tool 68 also includesone or more charge carriers 78 each of which comprises aplurality of charge assemblies 80. The charge carriers 78 andcharge assemblies 80 can be similar to, or constructed from,commercially available perforating guns. Upon détonation, eachcharge assembly 80 is adapted to blast an opening 82 through thecasing 56 and the concrète 58, and into the rock or other materialthat forme Zone F.

As shown in Figure 3D, each collar 64 includes anidentification device 72. Each identification device 72 can beattached to a résilient o-ring 86 placed in a groove 84 withineach collar 64. \\ o r î ' i : 12 1 « 8 9

In the illustrative embodiment, the identification devices72 comprise passive radio identification devices (PRIDs). PRIDsare commercially available and are widely used in applicationssuch as to identify merchandise in retail stores, and books inlibraries. The PRIDs include a circuit which is configured toresonate upon réception of radio frequency energy from a radiotransmission of appropriate frequency and strength. PassivePRIDs do not require a power source, as the energy received fromthe transmission signal provides the power for the PRIDs totransmit a reply signal during réception of the transmissionsignal.

The identification device 72 includes an integrated «circuitchip, such as a transceiver chip, having memory storagecapabilities. The integrated circuit chip can be configured toreceive RF signais and to encode and store data based on thesignais. During a data encoding operation each identificationdevice 72 can be uniquely identified such that each collar 64 isalso uniquely identified. This identification information isindicated by the C1-C8 désignations in Figures 3A and 3B. Inaddition, the depth of each collar 64 can be ascertained usingwell logs, as previously explained and shown in Figure 1. Thedepth information can then be correlated to the identificationinformation encoded into the identification device 72. A recordcan thus be established identifying each collar 64 and its truedepth in the well 52.

Alternately, as shown in Figure 3F, identification device72A can be in the form of an active device having a separatepower source such as a battery. In addition, the identificationdevice 72A can include an antenna 89 for transmitting signais.Alternately, an identification device (not shown) can beconfigured to transmit signais through a well fluid or othertransmission medium within the well 52. Such an identificationdevice is further described in previously cited parent applicationserial no. 09/286,650, which is incorporated herein by reference.

As also shown in Figure 3F, the identification device 72Acan be contained in a threaded mounting device 87. The threadedmounting device 87 can comprise a rigid, non-conductive materialsuch as a plastic. The threaded mounting device 87 is configured 13

to be screwed into the middle portions of the casing coliar 64(Figure 3D), and to be retained between adjacent tubular élémentsof the casing 56. The threaded mounting device 87 includes acircumferential groove 91 for the antenna 89, and a recess 93 forthe identification device 72A. If desired, the antenna 89 and theidentification device 72A can be retained in the groove 91 and therecess 93 using an adhesive or a suitable fastener.

Referring to Figure 3E, the reader device 70 is shown ingreater detail. The reader device 70 is configured to transmit RFtransmission signais at a selected frequency to the identificationdevices 72, and to receive RF response signais from theidentification devices 72. As such, the reader device 70 includesa base member 77 having a transmitter 73 configured to transmittransmission signais of a first frequency to the identificationdevices 72. The reader device 70 includes a receivér 71 on thebase member 77 configured to receive signais of a secondfrequency from the identification devices 72.

Preferably, the transmitter 73 is configured to providerelatively weak transmission signais such that oniy anidentification device 72 within a close proximity (e.g., one foot)of the reader device 70 receives the transmission signais.Alternately, the antenna of the reader device 70 can be configuredto provide highly directional transmission signais such that thetransmission signais radiale essentially horizontally from thereader device 70. Accordingly, the transmission signais from thereader device 70 are only received by a single identificationdevice 72 as the reader devices passes in close proximity to thesingle identification device 72.

In addition to the transmitter 73 and the receiver 71, thereader device 70 includes a cover 79 made of an electrically non-conductive material, such as plastic or fiberglass. The readerdevice 70 also includes o-rings 75 on the base member 77 forsealing the cover 79, and a cap member 81 attached to the basemember 77 which secures the cover 79 on the base member 77.In addition, the reader device 70 includes spacer éléments 83formed of an electrically non-conductive material such as ferrite,ceramic or plastic, which separate the transmitter 73 and thereceiver 71 from the base member 77. In the illustrative

'•Λ Ο ;> I 14 embodiment, the base member 77 is generally cylindrical inshape, and the spacer éléments 83 comprise donuts with a halfmoon or contoured cross section.

Referring to Figure 4A, an electrical schematic for theSystem 50 is illustrated. As illustrated schematically, eachidentification device 72 includes a memory device 110, in theform of a programmable integrated circuit chip, such as atransceiver chip, configured to receive and store identificationinformation. As previously explained, the identificationinformation can uniquely identify each casing coilar 64 with analpha numerical, numerical or other designator. In addition, usingpreviously prepared well logs, the depth of each uniquelyîdentified casing coilar 64 can be ascertained.

As also shown in Figure 4A, the reader device .70 includesthe transmitter 73 for transmitting transmission signais to theidentification devices 72, and the receiver 71 for receiving theresponse signais from the identification devices 72. The readerdevice 70 can be powered by a suitable power source, such as abattery, or a power suppiy at the surface. In addition, the readerdevice 70 includes a memory device 112, such as one or moreintegrated circuit chips, configured to receive and storeprogramming information.. The reader device 70 also includes atelemetry circuit 114 configured to transmit control signais indigital or other form, through software 116 to a controller 118,or alternately to a computer 122.

As is apparent the software 116 can be included in thecontroller 118, or in the computer 122. In addition, the computer122 can comprise a portable device such as a lap top which can bepre-programmed and transported to the well site. Also, as willbe further explained, the computer 122 can include a Visualdisplay for displaying information received from the readerdevice 70. The controller 118, or the computer 122, interfacewith tool control circuitry 120, which is configured to controlthe perforating tool 68 as required.

In the illustrative embodiment, the tool control circuitry120 is in signal communication with the detonator 74 (Figure 3C)of the perforating tool 68. The tool control circuitry 120 can belocated on the perforating tool 68, on the reader device 70, or at 15 •λ ;> οι lift jû~ « I 2 W Χ;> i the surface. The reader device 70 is programmed to transmitcontrol signais to the tool control circuitry 120, as a function ofresponse signais received from the identification devices 72. Forexample, in the perforating process illustrated in Figures 3A and3B, coupling' C4 is located proximate to the upper level, or entrypoint into Zone F. Since it is desired to actuate the perforatingtool 68 while it is in Zone F, the reader device 70 can beprogrammed to transmit actuation control signais through thetool control circuitry 120 to the detonator 74 (Figure 3C), when itpasses coupling C4 and receives response signais from theidentification device 72 contained in coupling C4. Becausecoupling C4 is uniquely identified by the identification device 72contained therein, and the depth of coupling C4 has beenpreviously identified using well logs, the perforating process canbe initiated in real lime, as the perforating tool 68 passescoupling C4 and enfers the section of the well casing 56proximate to Zone F.

However, in order to insure that the détonation sequence is l initiated at the right time additional factors must be considered.For example, the perforating tool 68 and reader device 70 can betransported through the well casing 56 with a certain velocity(V). In addition, the reader device 70 requires a certain timeperiod (T1) to transmit transmission signais to the identificationdevice 72 in coupling C4, and to receive response signais from theidentification device 72 in coupling C4. In addition, a certaintime period (T2) is required for transmitting signais to the toolcontrol circuitry 120 and to the detonator 74 (Figure 3C).Further, the charge assembües 80 require a certain time period(T3) before détonation, explosion and perforation of the casing 56occur. Ail of these factors can be considered in determiningwhich identification device 72 in which casing 64 will be used tomake the reader device 70 transmit actuation control signaisthrough the tool control circuitry 120 to the detonator 74 (Figure3C).

In order to provide proper timing for the détonationsequence, the velocity (V) of the perforating tool 68 and thereader device 70 can be selected as required. In addition, asshown in Figures 5A and 5B, a spacer element 88 can be used to ; Ιο Τ ΐ ÎÎ w 1 space the perforating tool 68 from the reader device 70 by apredetermined distance (D). As shown in Figure 5A, theperiorating tool 68 can be above the reader device 70 (i.e., doserto the surface 60), or alternately as shown in Figure 5B can be 5 below the reader device 70 (i.e., farther from the surface 60).

As an alternative to a dynamic détonation sequence, the perforating tool 68 can be stopped when the required depth isreached, and a static détonation sequence performed. Forexample, the reader device 70 can be programmed to send a signal 10 for stopping the perforating tool 68 when it reaches coupling C6.In this case, the signal from the reader device 70 can be used tocontrol the wire line unit 92 and stop the wire line 90. Thedétonation and explosive sequence can then be initiated by signaisfrom the tool control ' circuit 120, with the perforating tool 68 in 15 a static condition at the required depth.

As shown in Figure 4B, signais from the reader device 70 can be used to generate a Visual display 124, such as a computerscreen on the computer 122, which is viewable by an operator atthe surface. The Visual display 124 is titled "True Depth 20 Systems" and includes a power switch for enabling power to thereader device 70 and other System components. The Visualdisplay 124 also includes a "Depth Meter" that indicates the depthof the reader device 70 (or the perforating tool 68) within thewell 52. The Visual display 124 also includes "Alarm Indicators" 25 including a "Well Alarm Top" indicator, a "Well Alarm Bottom"indicator, and an "Explosive Device" indicator. The "AlarmIndicators" are similar to stop lights with green, yellow and redlights to indicate varying conditions.

The visual display 124 also includes "Power Indicators" 30 including a "True Depth Reader" power indicator, a "True DepthEncoder" power indicator, and a "System Monitor" power indicator.In addition, the Visual display 124 includes various "DigitalIndicators". For example, a "Line Speed" digital indicatorindicates the speed at which the reader device 70, and the 35 perforating tool 68, are being transported through the well casing56. An "Encoder Depth" digital indicator indicates the depth ofeach identification device 72 as the reader device 70 passes bythe identification devices 72. A "True Depth" indicator indicates 17 vîtvsM * the actual depth of the reader device 70 in real time as it istransported through the well casing 56.

The Visual display 124 also includes a "TDS ID" indicatorthat indicates an ID number for each identification device 72. Inaddition, the Visual display 124 includes a "TDS Description"indicator that further describes each identification device 72(e.g., location in a spécifie component or zone). The Visual display124 also includes a "Time" indicator that can be used as a timedrive (forward or backward) for démonstration or reviewpurposes. Finally, the Visual display 124 includes an "API Log"which indicates log information, such as gamma ray or SPEreadings, from the previousiy described well logs, correlated tothe "Digital Indicators" for depth.

Referring again to Figures 3A and 3B, in the embodimentillustrated therein, the transport mechanism 66W includes a wireline 90 opérable by a wire line unit 92, substantially aspreviousiy explained and shown in Figure 1. The wire line 90 cancomprise a slick line, an electric line, a braided line, or coiltubing. If the controller 118, or the computer 122, is located atthe surface 60, the wire line 90 can be used to establish signalcommunication between the reader device 70 and the controller118 or the computer 122.

Referring to Figures 6A-6D, alternate embodiment transportmechanisms for transporting the perforating tool 68 and thereader device 70 through the casing 56 are shown. In Figure 6A, atransport mechanism 66P comprises a pump for pumping aconveyance fluid through the inside diameter of the casing 56.The pumped conveyance fluid then transports the perforating tool68 and the reader device 70 through the casing 56. In Figure 6B,a transport mechanism 66R comprises one or more roboticdevices attached to the perforating tool 68 and the reader device70, and configured to transport the perforating tool 68 and thereader device 70 through the casing 56. In Figure 6C, a transportmechanism 66G comprises gravity (G) such that the perforatingtool 68 and the reader device 70 free fall through the casing 56.The free fall can be through a well fluid within the casing 56, orthrough air in the casing 56. In Figure 6D, a transport mechanism66PA includes a parachute which Controls the rate of descent of 18 '<4 fV-A- > < ï O * 1 the perforating tool 68 and the reader device 70 in the casing 56.Again, the parachute can operate in a well fluid, or in aircontained in the casing 56.

Referring to Figures 7A-7C, an alternate embodimentSystem 50A constructed in accordance with the invention isillustrated. The System 50A is installed in a subterranean well52A, such as an oil and gas production well. In this embodimentthe system 50A is configured to perform a packer setting processin the well 52A.

The well 52A includes a well bore 54A, and a well casing56A within the well bore 54A surrounded by concrète 58A. Thewell casing 56A comprises a plurality of tubular éléments 62A,such as lengths of métal pipe or tubing, connected to one anotherby collars 64A. The well 52A extends from an earthen surface60A through geological formations within the earth, which arerepresented as Zones H and I.

For performing the packer setting process, the system 50Aincludes a packer setting tool 68A, an inflation device 98A forthe packer setting tool 68A, and a reader device 70A in signalcommunication with the packer setting tool 68A. In thisembodiment, the inflation device 98A is located on the surface60A such that a wire, or other signal transmission medium mustbe provided between the packer setting tool 68A and the inflationdevice 98A. The packer setting tool 68A can include aninflatable packer eiement designed for inflation by the inflationdevice 98A and configured to sealingly engage the inside diameterof the casing 56A. In Figure 7B, the inflatable packer eiement ofthe packer setting tool 68A has been inflated to seal the insidediameter of the casing 56A proximale to Zone I.

The system 50A also includes a plurality of identificationdevices 72 (Figure 3D) attached to the collars 64A on the casing56A, and readable by the reader device 70A. In addition, thesystem 50A includes a transport mechanism 66A for transportingthe packer setting tool 68A and the reader device 70A through thewell casing 56A to Zone I. In this embodiment, the transportmechanism 66A comprises a tubing string formed· by tubularéléments 102A. As shown in Figure 7C, each tubular eiement102A includes a male tool joint 94A on one end, and a female tool 19 joint 96Α on an opposing end. This permits the tubular éléments102A to be attached to one another to form the transportmechanism 66A. In addition, the packer setting tool 68A caninclude a central mandrel in fluid communication with the inside 5 diameter of the transport mechanism 66A.

The reader device 70A is programmed to transmit a control signal to the inflation device 98A upon actuation by a selectedidentification device 72 (Figure 3D). For example, in the packersetting process illustrated in Figures 7A and 7B, coupling C4A is 10 located proximate to the upper level, or entry point into Zone I.Since it is desired to inflate the inflatable packer element of thepacker setting tool 68A whiie it is proximate to Zone I, the readerdevice 70A can be programmed to transmit the control signal tothe inflation device 68A when it reaches coupling C4A. In this 15 embodiment a spacer element 88A séparâtes the packer settingtool 68A and the reader device 70A. In addition, the packersetting tool 68A is located downhole relative to the reader device70A.

In order to insure that the packer setting sequence is

20 initiated at the right time additional factors must be consideredas previously explained. These factors can include the velocity(V) of the packer setting tool 68A and the reader device 70A, andthe time required to inflate the inflatable packer element of thepacker setting tool 68A. Alternately, the packer setting tool 68A 25 can be stopped at a particular coupling (e.g., coupling C5A) andthen inflated as required. In this case the reader device 70A canbe programmed to transmit the control signais to the Visualdisplay 124 (Figure 4B) on the surface 60A when the packer tool68A passes a coupling 64A at the required depth. The operator 30 can then control the inflation device 98A to initiate inflation ofthe packer setting tool 68A. Alternately the inflation sequencecan be initiated automaticàlly by the tool control circuit 120(Figure 4A).

In each of the described processes the method of the 35 invention provides an improved well. For example, in theperforating process of Figures 3A and 3B, the well 52 can beperforated in the selected zone, or in a selected interval of theselected zone. Production from the well 52 is thus optimized and 20 the well 52 is abie to produce more fluids, particularly oil andgas.

Referring to Figures 8A-8C, a multi stage operationperformed in accordance with the method of the invention isiilustrated. Initially, as shown in Figure 8A, a combination tool130 is provided. The combination tool 134 includes a packersetting tool 132 and a perforating tool 134, which functionsubstantially as previously described for the packer setting tool68A (Figure 7B), and the perforating tool 68 (Figure 3A)previously described. In addition, the combination tool 134includes the reader device 70 and the casing 56 includesidentification devices 72 (Figure 3D) substantially as previouslydescribed. As also shown in Figure 8A, the combination tool 130is transported through the casing 56 using the gravity transportmechanism 66G. Alternately, any of the other previouslydescribed transport mechanisms can be employed.

Next, as shown in Figure 8B, the packer setting tool 132 isactuated such that an inflatable packer element of the tool 132seals the casing 56 at a desired depth. In this embodiment thepacker setting tool 132 is a self contained unit, with an intégralinflation source. As with the previously described embodiments,the reader device 70 provides control signais for controlling thepacker setting tool .132, and the packer setting process. Forexample, the inflatable packer element of the packer setting tool132 can be inflated when the reader device 70 passes a selectedcoupling 64, and receives a response signal from theidentification device 72 contained within the selected coupling64. As also shown in Figure 8B, the perforating tool 134séparâtes from the packer setting tool 132 and continues to freefall through the casing 56.

Next, as shown in Figure 8C, the perforating tool 132 iscontrolled such that détonation and explosive sequences areinitiated substantially as previously described. Again the readerdevice 70 provides control signais, for controlling the perforatingtool 132 to initiate the détonation and explosive sequences at theproper depth. As indicated by the dashed arrows in Figure 8Cexplosion of the charge assemblies 80 (Figure 3C) of the 21 116 3, 1 perforating tool 134 forms openings in the casing 58 and theconcrète 58.

Thus the invention provides a method and a System forperformïng various operations or -processes in wells and for 5 improving production from the wells. While the invention hasbeen described with reference to certain preferred embodiments,as will be apparent to those skilled in the art, certain changesand modifications can be made without departing from the scopeof the invention as defined by the following daims.

Claims (12)

1. WHAT IS CLAIMED IS: 1189 i

   1. A method for performing an operation in a well comprising:providing a first device in the well which is uniquely identified and located at a known depth in the well; providing a second device configured to locate the first device in the well; transporting the second device through the well; and controlling the operation responsive to the second device locating the first device.
2. 2. The method of claim 1 further comprising transporting a processtool through the well with the second device and controlling the process toolresponsive to the second device locating the first device.
3. 3. The method of claim 1 wherein the first device comprises a radioidentification device.
4. 4. The method of claim 1 wherein the second device comprises aradio frequency transmitter configured to provide a transmission signal forréception by the first device and a receiver configured to receive a responsesignal from the first device.
5. 5. The method of claim 1 wherein the operation comprises a processselected from the group consisting of perforating processes, paçker settingprocesses, bridge plug setting processes, logging processes, inspectionprocesses, Chemical treating processes, casing patch processes, jet cuttingprocesses and cleaning processes.
6. 6. A System for performing an operation in a well comprising;a process tool configured for transport through the well; a plurality of radio identification devices located at spaced intervals atknown depths in the well configured to transmit response signais for uniquelyidentifying each radio identification device; and a reader device configured for transport through the well for receivingthe response signais from the radio identification devices and for controllingthe process tool responsive to the response signais. I 23 1 18.9 1
7. 7. The System of claim 6 wherein the reader device is attached to theprocess tool.
8. 8. The System of claim 6 further comprising a transport mechanism5 configured to move the process tool and the reader device through the well.
9. 9. The System of claim 6 wherein the reader device comprises areceiver for receiving the response signais and a transmitter for transmittingtransmission signais to the radio identification devices. 10
10. 10. The System of claim 6 wherein the process tool comprises aperforating tool and the control signal Controls a perforating process.
11. 11. The System of claim 6 wherein the process tool comprises a15 packer setting tool and the control signal Controls setting of a packer element.
12. 12. The system of claim 6 further comprising a computer in signalcommunication with the reader device comprising a Visual display generatedusing signais from the reader device. 20