GB2335453A - Downhole sensor for production well control - Google Patents

Abstract

A removable downhole sensor (94) for a production well is housed in a side pocket mandrel (86) having a primary bore (88) and a laterally offset side pocket (90). An opening is provided through a shoulder (97) defined by an upper surface of the side pocket (90), and a connector (99) of the sensor (94) is positioned through the opening. The connector comprises a capacitive, inductive or optical coupling.

Description

7) is 2335453 DOWNHOLE SENSOR

Background of the Invention 1. Field of-the Invention

The field of the present invention is generally the control of oil and gas production wells. more particularly, this invention relates to a downhole sensor with an inductive, capacitive or optical coupling.

This case was divided from GB 9908027.7 which is itself divided from GB 9621098.4. These are directed to a downhole sensor positioned on a side pocket mandrel with a wall between the pocket and primary bore, and to a subsurface valve position and monitoring system, respectively. GB9908019.4, GB9908018.6, GB9908017.8 and GB9908030.1 were also divided from GB 9621098.4. They are directed to a downhole inflation/deflation device, a remotely actuated tool stop, a remotely controlled fluid/gas control system and a remotely controlled valve 2 0 and variable choke assembly, respectively.

2. The Prior Art

The control of oil and gas production wells constitutes an on-going concern of the petroleum industry due, in part, to the enormous monetary expense involved as well as the risks associated with environmental and safety issues.

Production well control has become particularly important and more complex in view of the industry wide recognition that wells having multiple branches (i.e multilateral wells) will be increasingly important and commonplace. Such multilateral wells include discrete production zones which produce fluid in either common or J & is 1 3 o discrete production tubing. In either case, there is a need for controlling zone production, isolating specific zones and otherwise monitoring each zone in a particular well.

Before describing the current state-of-the-art relative to such production well control systems and methods, a brief description will be made of the production systems, per se, in need of control. One type of production system utilizes electrical submersible pumps (ESP) for pumping fluids from downhole. In addition, there are two other general types of productions systems for oil and gas wells, namely plunger lift and gas lift. Plunger lift production systems include the use of a small cylindrical plunger wich travels through tubing extending from a location adjacent the producing _p =P CP formation down in the borehole to surface equipment located at the open end of the borehole. In eeneral, fluids which collect in the borehole and inhibit the flow of fluids out of the formation and into the wellbore, are collected in the rubing. Periodically, the end of the rubing is opened at the surface and the accumulated reservoir pressure is sufficient to force the plunger up the tubing. The plunger carries with it to the surface a load of accumulated fluids which are ej.-cted out the top of the well thereby allowing gas to flow more freely from the formation into the wellbore and be delivered to a distribution system at the surface. After the flow of gas has again become restlicted due to the flirther accumulation of fluids downhole, a valve in the tubing at the surface of the well is closed so that the plunger then falls back down the tubing and is ready to lift another load of fluids to the surface upon the reopening of the valve.

A eas lift production system includes a valve system for controlling the injection of pr-essurized gas from a source external to the well, such as another gas well or a compressor. into the borehole. The increased pressure from the injected gas forces accumulated formation fluids up a central tubing ectending along the borehole to remove the fluids and restore the fr-,e flow of gas andlior oil frorn the formation into the well. Ln wells where liquid fbill back is a problem during gas lift, plung-Cr lift may be combined "ith gas lift to improve efficierCV. ere is a requirement for In both plunger lift and gas lift production s,, stems. th the ceriodle ocerntion of a motorvalve at the surfac ofthe to control either Z 9 1 ' . 1 is -)o the flow of fluids from the well or the flow of injection gas into the well to assist in the production of gas and liquids from the well. These motor valves are conventionally controlled by tirring mechanisms and are programmed in accordance with principles of reservoir engineering which determine the length of time that a well should be either ', shut in" and restricted from the flowing of gas or liquids to the surface and the time the well should be "opened" to freely produce. Generally, the criteria used for operation of the motor valve is strictly one of the elapse of a preselected time period. In most cases, measured well parameters, such as pressure, temperature, etc. are used only to overnde the timing cycle in special conditions.

It will be appreciated that relatively simple, timed intermittent operation o L' motor valves and the like is often not adequate to control either outflow from the well or gas Lnjection to the well so as to optimize well production. As a consequence, sophistj:cat-.d computerized controllers have be-en positioned at the surflace of production wells for control of downhole devices such as the motor valves..

In addition, such computerized controllers have been used to control other downhole devices such as hydro-mechanical safety valves. These typically microprocessor based controllers are also used for zone control witlfin a well and, for example. can be used to actuate sliding sleeves or packers by the tr-ansmission of a surface co=and to downhole microprocessor controllers and/or electromechanical control devices.

The surface controllers are often hardwired to downhole sensors which transmit in.formation to the surface such as pressure. temperature and flow. This data is then processed at the surface by the computeriZed control system. Electrically submersible pumps use p-,,sswe- and temperature readings received at the surface from downhole sensors to change the speed of the p=p in the borehole. As an altemarive to downhole sensors. "ire line production logging tools are, also used to provide dox, ,-nhole data on pressure. temperanwe, flo,., ga=a ray and pulse neutron using a wire line surface unit. This data is then used for control of the production well.

Therc.ve numerous prior art patents related to the control of oil an,-4 gas pr(-,du,:t:,,n In 2cn;-,r21. these pn-or r.i,,,-nts relate to (1) sur'ace control systerns li 1 using a sudace microprocessor and (2) dowrihole control systems which are initiated by surface control signals.

The surface control system patents generally disclose computerized systems for monitoring and controlling a gas/oil production well whereby the control electronics is located at the surface and communicates with sensors and electromechanical devices near the surface. An example of a system of this type is described in U.S. Patent 4,633,954 ('954) to Dixon et al. The system described in the'954 patent includes a fully programmable microprocessor controller which monitors downhole parameters such as pressure and flow and controls the operation of gas injection to the well, ouuow of fluids from the well or shurtincy in of the well to maximize output of the well. T'rjs particular system includes battery powered solid state circuitry comprising a keyboard, a programmable memory, a rricroprocessor, control circuitry and a liquid crystal display. Another example of a control system of this type is described in U.S. Patent 5,132,904 ('904) to Lamp. The'904 patent discloses a system similar to the '954 patent and in addition also describes a fearure wherein the controller includes serial and parallel communication ports through which all cornmunications to and from the controller pass. Hand held devices or portable computers capable of serial com.munication may access the controller. A telephone modem or telemetry link to a cenn-al host computer may also be used to permit several controllers to be accessed remotely.

U.S. Patent 4,757,314 () 14) to Aubin et al describes an apparatus for controlling and monitoring a well head submerged in water. This system includes a plurality of sensors, a plurality of electromechanical valves and an electronlic control system which communicates with the sensors and valves. The electronic control systern is positioned in a water tia-ht enclosure and the water tight enclosure is submerged underwater. The electronics located in the submerged enclosure control and operate the electromechanical valves based on input from the sensors. In panicular, the electronics in the enclosure uses the decision making abilities of the microprocessor to morutor the cable integrity from the surface to the well head to aLtomalicall,. open or close the x.al,.c:s should a break in the line occur- _ 1 J Z The downhole control system patents generally disclose downhole microprocessor controllers. electromechanical control devices and sensors. Examples include U.S. Patent Nos. 4,915,168 (168) to Upchurch and 5,273, 112 ('112) to Schultz. However, in each and every case, the microprocessor controllers transmit control signals only upon actuation from a surface or other external control signal. There is no teaching in any of these patents that the downhole microprocessor controllers themselves may automatically initiate the control of the electromechanical devices based on preprogrammed instructions. Similarly, none of the aforementioned patents directed to microprocessor based control systems for controlling the production from o'I and eas wells, including the aforementioned '954, '904 and '3 14. parents, disclose the use of downhole electronic controllers, electromechanical control devices and sensors where-by the electronic control units automatically control the el,e-.trorn--charical devices based on input from the sensor without the need for a surface or other exiernal control signal.

It mill be appreciated that the downhole control system of the types disclosed in the '168 and '112 patents are closely analogous to the surface based control systems such as disclosed in the '954, '904 and '3 14 patents in that a surface controller is required at each well to initiate and u=mit the control instructions to the dovnffiole microprocessor. Thus, in all cases, some type of surface controller and associated support platforni at each well is needed.

ile it is well recognized that petroleum production wells.,,,,ill have increased production efficiencies and lower operating costs if surface computer based controllers and doAnhole microprocessor controller (2cruated by external or surface signals) of the type discussed hereinabove are used, the presently implemented control systems nevertheless suffer from drawbacks and disadvantages. For exaMr)le,,2S mentioned, all of these prior an systems generally require 2 surfaceplatform at each well for supporting the control electronics and associated equipment. However, in many instances, the well operator would rather forego building and maintaining the cosily platform. Thus. a problem is encountered in that use of present surf:ic.- controllers r-qulrz. the p,-,,sz-.nce of a location for the control systern. n ly th 1 tfo 1 1 ame c 0 arm. Still 1 1 1 1 i 30 another problem associated with known surface control systems such as the type disclosed in the'I 68 and'I 12 patents wherein a downhole microprocessor is actuated by a surface signal is the reliability of surface to downhole signal integrity. It will be appreciated that should the surface signal be in any way compromised on its way downhole, then important control operations (such as preventing water from flowing into the production tubing) will not take place as needed.

in multilateral wells where multiple zones are controlled by a single surface control system, an inherent risk is that if the surface control system fails or otherwise shuts down, then all of the downhole tools and other production equipment in each separate zone will similarly shut down leading to a large loss in production and. of course, a loss in revenue.

Still another significant drawback of present production well control systems involves the ex-jemely high cost associated with implementing charges in well control and related workover operations. Presently, if a problem is detected at the well, the customer is required to send a rig to the wellsite at an extremely high cost (e.g., 5 million-dollars for 30 days of offshore work). The well must then be shut in during the workover causing a large loss in revenues (e.g., 1.5 million dollars for a 3)0 day period). Associated with these high costs are the relatively hieh risks of adverse environmental impact due to spills and other accidents as well as potential liability of personnel at the rig site. Of course, these risks can lead to even finther costs. Because of the high costs and risks involved, in general, a customer may delay important and necessan. workover of a single well until other wells in that area encounter problems. TEs delay may cause the production of the well to decrease or be shut in until the rig is brought in.

Still other problems associated with present production well control systems involve the need for wireiffie formation evaluation to sense changes in the formation and fluid composition. Unforrunately, such,,, irclt"ne formation evaluation is extremely expensive and time consuming. In addition. it requires shut-in of the well and does not provide "real time" information. The need for real time information regarding the formation and fluid is especially acute in evaluating undesirable water flow into the production flulds.

7 22Mna_ry- of the Invention The above-discussed and other problems and deficiencies of the prior art are overcome or alleviated by the production well control system described herein. A downhole production well control system is provided for automatically controlling downhole tools in response to sensed selected downhole parameters. An important feature is that the automatic control is initiated downhole without an initial control signal from the surface or from some other external source.

The present invention provides a downhole sensor comprising: a side pocket mandrel having a primary bore and a laterally offset side pocket; a removable downhole sensor residing in said side pocket; an opening through a shoulder defined by an upper surface of said side pocket for receiving a sensor connector; and said sensor connector operable to provide capacitive, inductive or optical coupling with said sensor.

7 1 1 9 1; Ihe fixst system described generally cmpri-c,--s dole sensors, do,;,- rLhole electromechanical devices and do'iole compu!....rized control electronics wbereby the control electrorics automatically control the elec-,.omechaiiical devices based on input from the downhole sensors. Thus, usin-9 the downhole sensors, the downhole computerized control sys-m will monitor acrual dow-.in.ole parameters (such as r)ressiL-e, temperarure, flow, gas irLflv-x. etc.) and automatically execute control i,-is-,jctiori when the monitored do,.,,7ole parameters are outside a selected operating raree (e.e., indicating an unsafe condition). The automatic cont-ol in=uctions %kill then cause an electromechanical control device (such as a valve) to actuate a suitable tool (for example, actuate a sliding sleeve or packer., or close a p=p or other fitid flow device).

The downhole control systern also includes transce'vers for two-way cor=urcation with the surface as well as a telemetry device for communicating from the surface of the production well to a refflOte 10C3tion.

The downhole control sysiern is prtfc.-ably located in each zone of a well such that a plurality of wells associated,.,,ith ore or rnort platforms will have a of do,,,T.olc eontrol svstcms. one for each zcnc;n cach. 71e do,.k-rhce cc- rroi s-,.s-,czis hi - Ch _ abillrl; to COW=,--.ICZ:C -n other zones in sar-e or dlffcr-,nt wcl!s. Ln ad":ZIOD. each downhole concrol system in a zone m.3y. 1150 cornmuriic2tt vlith 1 sufficc control SYS1cm. ne do%.nhole control Ot is :s well suited for use in cor.nection %4ntn multilatera! wells which 'include multiple zones.

The selected operating range for each tool controlled by the doynihole control SYSICM is programmed in a downhole memory either before or after the control systern is lowered downhole. The aforementioned transceiver may be used to ch&-ige thee operating wge or alter the programming of the concol system from the surface of the well or from a remote locadon.

A power source provides energy to the downhole control system. Power for the powe: sou::: can be generated in t-he borChole (e.g., by a turbine g.,,i.-rator), at the surface ortc supplied by energy storage devices such as banel-ies (or a combination of one or mort of these power, sources). The power source provides elecrrical voltage and CI.L-:ei! do%k-nhol-. electronics, ele-.-Uomechanical devices and sensors in the b or -1 h o', - Ln cona-ast to the aforernentioned prior art well control systems which consist eitber orcor-r)uter systems located wholly at the stuface or do"-.ihol;! compute:

syr,--,,ns w-,ch require wri external (e.g., surface) initiation signal (as well as a surface control svrem), the downhole well production control system describai herein automatically operates based on downhole conditions sensed in real timeArithout the need for a surface or other external signal. This important feature consdtutes a signfficant advance in the field of production well control. For example, use of the downhole control system. obviates the need for, a surface platform (although s,.,c.h surface platforms may still be desirable in certa,= applications such as whez amernote monitoring and control f3ciliry is desirtd as discussed below.

-rhe do%knhole control SYSI1CM is also inherend%.,-.iort reliable since no sur:-3ce to do"-, ihole acn.a..c:i s pal is r,-q 'red and ih.- assec a::!d 'sk 1-3 such ar. 3z:r- a:on Signal be 1 ul n -1 corn is Chcrefortre-dc-.-td rnoc,,. to wells, s,,ill a.,:othcr advantage is Lhat, because Che enure- producdon well and its multiple zones are not con=llcd by a single surfic: controller. then the ) 1 -)o 1 to risk that an entire well including all of its discrete production zones will be shut-in simultaneously is greatly reduced.

A system adapted for controlling and/or monitoring a plurality of production wells from a remote louatien is aim provicbi- m-dz sy,," js 'Weble Of COntro 11 ilig and/or rninit3riM:

(1) a plurality of zones in a single production well; (2) a plurality of zones/wells in a single location (e.g., a single platform); or (3) a plurality of zones/wells located at a plurality of locations (e.g., multiple platforms).

The multizone and/or multiwell control system is comoosed of multiple do,.,,-nhole electronically controlled electromechanical devices (sometimes referred to as do"mhole modules), and multiple computer based surface systems operated from multiple locations. Important functions for these systems include the abiliry to predict the future flow profile of multiple wells and to monitor and control the fluid or eas fiow from either the formation into the wellbore, or from the wellbore to the surface. The control system. is also capable of receiving and transmitting data from multiple remote locations such as inside the borehole, to or from other platforms, or from a location away from any well site.

The downhole control devices interface to the surface s-,lstem using either a Y,,,ireless commurication system or through an electrical hard wired connection. The do.,knhole control systems in the wellbore can Ua=it and receive data and/or ornmands toifrom the surface system. The data transmission Eom inside the wellbore can be done by allowing the surface system to poll each individual device in the hole, althoueh individual devices will be allowed to Like control of the commurcations dudne ar. err..-:genc,v. The devices dowTihole may be prow==ci. In the wellbort. by s..ndnp, the prope, command -,nd data to adjust Lc 2ira.-n,- tc,-s being monitored due to changes in borehole and now conditions andior to change its primary fu.nction in the wellbore.

1 1.

-Is 1 1 f 1 L T-he surface system maY control the activities of the do.Amhoe modules by requesting data on a periodic basis, and commanding the modules to open or close the electromechanical control devices, and/or change monitoring parameters due to changes in long term borehole conditions. The surface system at one location will be capable of interfacing with a system in another location via phone fines, satellite com.rnulucation or other communicating me=. Preferably, a remote central control system controls and/or monitors all of the zones, wells and/or platforms from a single remote location.

D-,e downhole control s-,.stems are associated with permanent downhole formaJon evaluation sensors which remain downhole throughout production operations. These fo,-,nadon evaluation sensors for formation measurements may include, for example, c=.a ray detection for formation evaluation, neutron porosity, resistivity, acoustic sensor-s and pulse neuTzon which can, in real time, sense and evaluate formation pa-ame-,ers Ir-cluding importan., information regarding water mi-grating. from different zones. Sj=-,:ficantly, ti-iis inform, ation can be obtained prior to the water actually ente-,ne, thl- producing tubing and therefore corrective action (i.e., closing of a valve or sliding sle-.ve) or formation treatment can be taken prior to water being produced. This real time acquisition of formation data in the production well constitutes an important advance over current wireline techniques in that the present systú2fn is fix less cosLIv and can a.nticipate- and =ct to potential problems before they occur. In addition, the formation evaluation sensors themselves can be placed much closer to the acrual forni-ation (i.e., adjacent the casing or downhole completion tool) then Yireline devices which are restricted to the interior of the production tubing.

The above-discussed and other feanL-ts and advantages okthe rivention "ill be a2cr.-clared by and unde,-s,,,.,od by ihos- sMIed ir The art detailed de-scription and dm,.,.ngs.

1 1 1 n 5 1;L arief Descd2Jon of the Dmwirig:

Referring now to the drawings, wherein like elements are numbered alike in the several FIGURES:

FIGURE 1 is a diagrar=atic view depicting the rnuitiwell/muldzone controi system for use in controlling a plurality of offshore well platforms; FIGURE 2 is an enlarged diagrammatic view of a portion of FIGURE 1 depicting a selected well and selected zones in such selected well and a downhole conrxol system for use therewith; FIG 3 is an enlarged diagramm.aric view of a ponior. of FIGUTRE 2 delpicrirg control syste= for both open hole and cased hole completion zones; FIGURE 4 is a block dia-c-.= depicting the muliiwelL'.-,iultizone control system; is a block d;ac--a,-n depictincr a surface conc:,-1 "c.- use.,,ith the corwol s.,.STerr..

F, GU-RE SA is a block diagrarn of a communications synern using sensed downhole press= conditions; FIGURE 5B is a block d.,a== ofa pordon of the corrr-.unicadons system of FIGURE SA, F,1GI-RE 5C is a block dilc_,-= oftle data aQqtdsidon us,-d;-,i thl- Surface cl-r=l systern of FIGURE S; F.C.LRE 6 is a block di3gr2.-n g a do%,,mhole we'l cont:ol gv"-tcm; FIC,LrR..C_ 7 is an clecLic-,1 s-.hem:iljc ol"thc C40'.knhO!e cr-,4-uc,. 'cr.

cor=ol C;,'FICURE 6..

c n V1 -- w 0 f a 7C t c is a cross -Jnal side -cc,2t FIGURE 8A is an enlarged view of a portion of FIGUR.7E 3.

FIGURE 9 diaewwTvnat;c v',-v of a subsurfact nosidon =d 13 FIGURE 10 is a diagrammatic view of a remotely controlled trulation/deflacton device for downhole pressure monitoring; FIGURES 11 A and 11 B are diagrammatic views of a system for remotely acruated downhole tool stops in respective extended and retracted positions; FIGURE 12 is a diagrammatic view of a remotely controlled fluid/gas control syslern; FIGURE 13 is a diagrammatic view of a remotely controlled shut off valve and variable choke assembly; FIGURE 14 is a cross-sectional side elevation view ofa downhole- formation Clialuajon sensor; a=d FIGURES 15A-D arel a sequential cross section view of the upside down side pocker mandrel in accordance with the present invention.

Desc,-:.,ior. of the Preferred Erncodi,-,ie-.t:

Ll-me:-:ol icwim desc-rites a sys,t:m for controlling produ re-.,ot.-'iocajon. In ParTicular, a concol and monitor-na sy.stem is described for controlling andfor monitoring a., zones in a single well úrom a remote location. A.1so covered is the remte control andior monitoring of multiple wells at a single platform (or other location) ar.di'or =ultple wells located at muldc[.- platfo= or locader-s. 7hus, &. t con=l sys-..-rr ' has the ibility to control individual --?ones'= multiple w-,115 ca muldpic platforms, all iom ammort locadon. Tric control and., 'cr rnoritorirls! is comprised of i plu:-.311r,v Of surfact- coneol syst.--ns or Modules locattd at each well head and one or mort- downllole cont-ol sysc. ,ns or rr.c,-.jtjds ces dorcd.viLhir. zones!oca,.-,j in::ich ytil. 11low --g an zoncrot &orr, a s' gte ecajen o azc MC C.1 1 c 1 n c ZO r. e numbe: j s in near rcall c.Lne.

s'llbed'scuss,:dnsomcd,- -LcIG 52.

r v. U RE 6 and svS(,- m, s zomPosc,' the L 4- 0 clectroru'cs and downhole electromecharuical modules that can be placed in ditTeTent locations (e.g., zones) in a well, with each downhole control systern having a unique electronics address. A number of wells can be ourfitted with these downhole control devices. 'Fne surface control and monitoring system interfaces with all of the wells where L'-e downhole control devices are located to poll each device fror data related to the status of the downhoIc sensors attached to the module being polled. In general, the surface systeni allows the operator to control the position, status, and/or fluid flow in each zone of the well by sending a command to the device being controlled in the wellbore.

ill be discussed herti,-iafte.-. Le do,kmbole control ril.odLl--s fc7 USe in the As v, 1 1 middzore or multiwell control -;stem 1 may either be. conzolled using an eae.-,al or surface cominand as is k-,io,,,,-n in the = or the dowTiho, .. co.=rol sy t m c mav be ac-,L,-,r.-d automatically in accor,.--,,-c-- with a novel com- 1 sy -0.

co.-,:.-ols.-e activities in the wellbore- by r.-ior-itorL-ia the well se. o c r t r d 0 r-srs 0,rze. the da:a electronics. Li th.- latte: cas.c. a doA-,ihole cor-:uz-.:..Z.C micropm-cessor) will co=and a downlrole tool such as a oack--:, sli--;'nc, or valve to open, close, change state or do whateve,r other action is r,-qC,- ed 1.--C-.rtain sensed parameters are outside the normal or preselecred well zone oc.-, t -Z ae.

ra L- rangThis operating range may be prograrnmed into the system either prior co bc.-g placed in t.- ber-thele or such pro _zra=-ng may be -!1e,..,--d by a corn-mand ----orr. -he surface Ibo aRC-7 the do%,,--hole control module has positiored in..,e w.... r:

R.-fer.:ng now to FIGURES 1 an,4.4. t.c mulclweiV-,,,u!Czon-:ror.-:.on-ng and ont:ol synern, may nclud-- a rernott cc,z.--d zonni conitr 1 which corun.unicates ciLhctr wirelessly cr.,dat-!t-,j'ncne ".",rts r,: a placfcr-.,s 12. It be Lha, =v o;4,.,.til by the concrol pr::s:-ic inv--n".c.n Wth n an., c 1 y. p 1 a tc rm 1. p 1 a co rm. 2. w,,-4 p 1 nn. N b c;-- 9 5 h. 0 Wn ', n FIG LTRI S 4.

Each well placform ha-s associated ther,-1.1Lh a pluraltry of wells 14 vbjzh t.X--.nd from each olat"orm, 12 through,vacc-. 16 to hc surfac: of the Oct-Ul floor and ten yinto formations under Rocr tt,1, il! be 1.,hlle f 1.

1 5 offshore platforms 12 have been shown in FIGURE 1, 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 1 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 specificareas of a well for purposes ofproducing selected fluids, preventing blowouts and preventing water intake. Such zones may be posidoned in a sinale vertical well such as well 19 associated with platform 2 sho" in FIGURE 1 or such zones can result when multiple wells are linked or othen,,ise joined together. A particularly sigrifficant contemporary fearure of well production is the driliL,la and completion of lateral or branch wells which extend from a parcular primary wellbore. These lateral or branch wells can be completed such that each lateral well cowirutes a separable zone and can be isolated for selected production. A more complete description of wellbores containing one or more laterals (known as multilaterals) can be found in U.S. Patent Nos. 4, 807,407, 5,325,924 and U.S. Application Serial 08/187,277 (now U.S. Patent No.5,411,082), all of the contents of each of those patents and applications being incorporated herein by reference.

With reference to FIGURES 1-4, each of the wells 1, 2 and 3) associated with platform 1 include a plurality of zones which need to be monitored and/or controlled for efficient production and management of the well fluids. For example, with reference to FIGURE 2, well number 2 includes three zones, namely zone number 1, zone nwnber 2 and zone number N. Each of zones 1, 2 and N have been completed ffi a known m=er; and more panicularly have be.-n completed ffi the manner disclosed in aforementioned Application Serial No. 08.187,277. Zone number 1 has been completed using a known slorted liner completion. zone number 2 has been completed using an open hole selective completion and zone number N has been completed using a cwej [joic selective completion,.lth sliding, slec, ,,-es. Associated with each of zones 1 I(# 1. 2 and N is a downhole control system 22. Similarly, associated with each well platform 1, 2 and N is a surface control system 24.

As discussed, the multiwell/multizone control system is comprised of multiple downhole electronically controlled electromechanical devices and multiple computer based surface systems operated from multiple locations. An important function of these systems is to predict the future flow profile of multiple weIls 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 transmitting data from multiple locations such as inside the borehole, and to or from other platforms 1, 2 or N or from a location away from any well site such as central control c--nter 10.

The downhole control systems 22 will interface to the surface system 24 usincy a wireless communication system or through an electrical wire (i.e. , hardwired) connection. Tle downhole systems in the wellbore can transmit and receive data and/or commands to or from the surface and/or to or fromother devices in the borehole. Referring now to FIGURE 5, the surface system 24 is composed of a computer system 30 used for processing, storing and displaying the information 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 and 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 accomplished ushig 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 and downhole is available).

A surface to borehole transceiver 34 is used for sending data dommhole and for receiving the information u-a=itted from inside the wellbore to the surface. The n=ceiver converts the pulses received from downhole into signals compatible with the surface computer system and converts signals ftom the computer 30 to an appropriate cornmunications means for co=iunicatinQ downhole to do,.%-nhole control 11 7; -)o ns system 22. Communications downhole may be effected by a vaiier/ of knovm rnethods including hardwiring and wireless communications techniques. A preferred technique transmits acoustic signals down a tubing string such as production tubing string 38 (see FIGURE 2) or coiled tubing. Acoustical communication may include variations of signal frequencies, specific frequencies, or codes or acoustical signals or combinations of these. The acoustical transmission media may include the tubing string as illustrated in U.S. Patent Nos. 4,375,239; 4,347,900 or 4,378,850, all of which are incorporated herein by reference. Alternatively, the acoustical transmission may be transmitted throueah the casing stream, electrical line, slick line, subterranean soil around the well. t-ubln2.'-'L,id or annulus fluid. A preferred acoustic transmitter is described in U.S. Patent No. 5.21-227,049, all of the contents of which is incorporated herein by reference thereto. which discloses a ceramic piezoelectric based tr=ceiver. The piezoelectric wafers that compose the transducer are stacked and compressed for proper coupling to the rn.e-,-",xn used to carry the data inforrnation to the sensors in the borChole. Tbis u-a. nsductr,.;,ill generate a mechanical force when alternating current voltage is applied to the r,.vo power inputs of the =sduc-.,. Tle signal generated by stressing the piezoelectric wafers will travel along the axis of the borehole to the receivers located in the tool assembly where the signal is detected and processed. The transmission medium where the acoustic signal will travel in the borehole can be production tubinga or coil rubing.

Communications can also be efFected by sensed downhole pressure conditions which may be nanu-al conditions or which may be a coded pressure pulse or the like introduced into the well at the surface by the operator of the.well. Suitable systems escribt"na in more detail the nature of such coded pressure pulses are described in U.S.

Patent Nos. 4.712,61 to Nieuwstad, 4,468,665 to Thawley, 3.23 1674 to Leum-vier and 4.07S.620 to X'estlak.,-; 5,22-6,494 to Rubbo et al and 5,343.963 to Bouldin et al.

the aforementioned '168 patent to Upchurch and'I 12 patent to Schultz, also disclose the use of coded pressure pulses in communicating from the surface do,,-nhole.

preferred system for sensing do,,mhole pressure conditions is depleted in FIGURES 3.-\ and 5B. Refe 'no dheld M, -, to FIGURE 5.-\, this system Includes a hap.

[ 5 terminal 300 used for programming the tool at the surface, barieries (not shown) for powering the electronics and actuation downhole, a microprocessor 302 used for interfacing with the handheld terminal and for setting the frequencies to be used by the Erasable Prograrnmable Logic Device (F-PLD) 304 for activation of the drivers, preamplifiers 306 used for conditioning the pulses from the surface, counters (EPLD) 304 used for the acquisition of the pulses transmitted from the surface for determination of the pulse frequencies, and to enable the actuators 306 in the tool; and actuators 308 used for the control and operation of electromechanical devices and/or ignitors.

Refer=g to FIGURE 5B, the EPLD system 304 is preferably comprised of six counters: A four bit counter for surface pulse count and for conjol of the actuation of the electromechanical devices. A 10 bit counter to reduce the frequency of Clock in from 32.768 KHz to 32 Hz; and a 10 bit counter to count the deadtime frequency. Two counters are used to determine the proper frequency of pulses. Only one frequency counter is enabled at any time. A shift register is set by the processor to retain the frequency senings. The 10 bit devices also enable the pulse counter to increment the count if a piJsl- is received after the deadtime elapse, and before the pulse window count of six seconds expire. The system,.,ill be reset if a pulse is not received during the six seconds valid period. An AND gate is located between the input pulses and the clock in the pulse counter. The AND gate will allow the pulse from a sn-ain gauge to reach the counter if the enable line from the 10 bit counter is low. A two input OR gate will reset the pulse counter from the 10 bit counter or the master reset from the processor. A three input OR gate will be used for resetting the 11, 10 bit counters, as Well as the frequency counters.

The communications system of of FIGURES SA and 5B may operate as follows:

Set the tool address (freq,-,-ncies) using the band.,-ld tlerminal at the surface.

2. Use the handheld terminal to also set the time delay for the tool to t= itself on and listen to the pulses =smined from the surface:

1 R 3 The processor 302 will set the shift register with a binary number which will indicate to the counters the frequencies (address) it should acknowledge for operation of the actuators; 4. The operator will use an appropriate transmirter at the surface system 24 to generate the proper frequencies to be sent to the tool downhole; 5. The downhole electronics 22 will receive the pulses from the surface, determine if they are valid, and tum on or off the actuators; 6. In one preferred embodiment described in steps 6-8, there are a total of sixteen different frequencies that can be used to activate the sysiems downhole. Each downboic svRem will require two frequencies to be sent from the surface for proper activation.

1 - to the tools' processor 302 to set the 1 The surface system 24 will interface two frecuencies for com. rnunication and activation of-the systems in the borehole. Each frequency spaced at multiples of 30 seconds intervals is composed of four pulses. A s-,,,,s,.-m do,,,,-nhole will be activated when 8 pulses at the two preset frequencies are received by the electrorLics in the tool. There has to be 4 pulses at one frequency followed by 4 pulses at a second frequency.

3. A counter will morfitor the frequencies downhole and %kill reset the hardware if a pulse is not received within a 6 second window.

Also, other suitable communications techniques include radio nwsniission from the surface location or from a subsurface location, with corresponding radio feedback from the downhole tools to the surface location or subsurface location; the use of microwave =srrLission and reception; the use of fiber optic co=unications through a fiber optic cable suspended from the surface to the downhole control package; the use of electrical signaling from awire line suspended =srru'rter to the downhole control package IVIth subsequent feedback from the control package to the lire suspended n=srn;-,,-r/r,-c,-"lver. Commurd cation may allso consist of frequencies. =plitudes, codes or variations or combinations of these pararneters or a =.sforrner coupled techi-Lique which involves,,vire line conveyance of a parial =sforme-, to a downhole tool. Either the pr-im.irv or secondary of the =sforrner is conveyed on a x,ire line 210 with the other half of the transformer residing within the downhole tool. When the two portions of the =sformer are mated, data can be interchanged.

Referring again to FIGURE 5, the control surface system 24 further includes a printerlplotter 40 which is used to create a paper record of the events occurring in the well. The hard copy generated by computer 30 can be used to compare the status of different wells, compare previous events to events occurring in existing wells and to get formation evaluation logs. Also communicating with computer control 30 is a data acquisition system 42 which is used for interfacing the well transceiver 34 to the computer 30 for processing. -Re data acquisition system 42 is comprised of analog and digi-A inDuts and outputs, computer bus interfaces, high voltage interfaces and shmal processing electronics. An embodiment of data acquisition sensor 42 is shovm in EGURE 5C and includes a pre-amplifier 320, band pass filter 322, gain controlled a=lifier 324' and analo.g to digital converter 326. The data acquisition s7VS1em, (ADC),4i11 process the analo-R signals detected by the surface receiver to conform to the required inpu: specifications to the microprocessor based data processing and control

M system. he surface receiver 34 is used to detect the pulses received at the surface from imide the wellbore and convert them into signals compatible with the data acquisition pr-eamplifier 320. The signals from the transducer will be low level analog voltages. The preamplifier 320 is used to increase the voltage levels and to decrease the noise levels encountered in the original signals from the transducers. Preamplifier 320 will also buffer the data to prevent any changes in impedanc-e or problernswith the tran.sducer from damaging the electronics. The bandpass filter 322 eliminates the hia 1 gh And low frequency noises that are generated from external sour-c-es. 'Re filter,"ill allow the signals associated Y;ith the transducer frequencies to passwithout any sixnificant distortion or attenuation. Thl- gain controlled amplifier 324 monitors the voltage level on the input signal and amplifies or attenuates it to assur-- tha: 11 staYs,within &,c acquired volLige =ges. The sigmals are conditioned to have the highest possible range to provide the largest resolution that can be achieved i,, id-dn the system. Finally, the analog to digital converter 3-26 ill transform the analog slemal received Unpl:ic:r V110 a diQita[ value to the leve! of the analog ,x signal. The conversion fl-om analog to digital will occur after the microprocessor 30 commands the tool to start a conversion. The processor system 30 will set the ADC to process the analog signal into 8 or 16 bits of information. The ADC will inform the processor when a conversion is taking place and when it is competed. The processor 30 can at any tirne request the ADC to transfer the acquired data to the processor.

Still referring to FIGURE 5, the electrical pulses from the tramceiver 34 will be conditioned to fit within a range where the data can be digitized for processing by computer control 30. Communicating with both computer control 30 and t=sceiver 34 is a pr-eviously mentioned modem 36. Modem 36 is available to surface system 24 for =mission of the data from the well site to a remote location such as remote location 10 or a different control surface system 24 located on, for example, platform 2 or platfo rm, N. At this remote location, the data can be viewed and evaluated, or again, si,-.n,r)lv be communicated to other computers controlling other platforms. rhe remote cornpu.er 10 can take control over system 24 interfacing with the dow-ahole control modules 22 and acquired data from the wellbore and/or control the status ofthe dow-nhoie devices and/or control the fluid flow from the well or from the formation. Also associated with the control surface system 24 is a depth measurement System which interfaces with computer control system 30 for providing information related to the location of the tools in the borehole as the tool string is lowered into the ground. Fly, control surface system 24 also includes one or more surface sensors 46 which are installed at the surface for monitoring well parameters such as pressure, rig pumps and heave, all of which can be connected to the surface system to provide the operraior with additional information on the status of the well.

Surfac-. sysiem 24 can control the activities of the downhole control modules 22 by requesting data on a periodic basis and co=anding the dow-nhole modules to open, or close -lecL-ornechxi-ical devices and to change monitorincy dut- to changes in Iona term borehole conditions..-Xs shov..n diagrammancally in FIGL7RE 1, surface system 24, at one location such as platform 1. can intefficl. %Aith a surface system '14 at a difTerent location such as platforms 2 or N or the clentral remote control sensor 10 via ohone Ilines or via,,"lreless transmission. For examcIc. in FIGUR-E 1, J-2- 0 each surface system 24 Is associated with an antenna 48 for direct communication with each other (i.e., from platform 2 to platform N), for direct communication with an antenna 50 located at central control system 10 (i.e., from platform 2 to control system 10) or for indirect communication via a satellite 52. Thus, each surface control center 24 includes the following functions: 1. 2.

Polls the downhole sensors for data information; Processes the acquired information from the wellbore to provide the operator with formation, tools and flow status; 3. Interfaces with other surface systems for n=fer of data and commands; and 4. Provides the interface between the operator and the downhole tools and sensors.

In a less preferred version the downhole control system 22 may be comprised of any number of known downhole control systems which require a signal from the surface for actuarion. Examples of such downhole control sysiems include those described in U.S. Patent Nos. 3,227.2228; 4,796,669; 4,896..722, 4.915,168. 5.050,675; 4,856,595; 4,971,160; 5,273,112.-.5,27-^),113; 5, 332.035; 5.293.937. 5-226,494 and 5,343,963, all ofthe contents of each patent being incorporated herein by reference thereto. All of these patents disclose various apparatus and methods wherein a microprocessor based controller downhole is actuated by a surface or other external signal such that the microprocessor executes a control sienal which is n=rnitted to an electromechanical control device which then acmates a downhole tool such as a slidine sleeve, packer or valve. In this case. the surface control svstem 24 n=mits the actuation signal to downhole controller 22.

Tbus. the aforementioned remoic centra] control center 10, surface control centers 24 and do%,- nhole control ide one or more of te follo'll'lr,.g medons:

systems 222 all cooperate to provi U ri U' ---n 2 -Lid a 1. Provide one or rwo-way comm ca on benveen the 4 dovmhole tool via dos,.-nhole control systern Acqu. process. display and,;or store at the surface data =,smirted frorn do"nhole relating to the wellbort fluids. gases and tool status parameters acqu',-,-d by sensors in the wellbort.

g 3 4.

-)o 5. 6, 7.

8.

9.

Provide an operator with the ablitry to control tools downhole by sending a specific address and command information from the central control center 10 or from an individual surface control center 24 down into the wellbore; Control multiple tools in multiple zones within any single well by a single remote surface system 24 or the remote central control center 10; Monitor and/or control multiple wells with a single surface system 10 or 24 Monitor multiple platfo= from a single or multiple surface system working together through a remote comrnunicaflons link or working individually; Acquire, process and transmit to the surface from inside the wellbore multiple pararneters related to the well status, fluid condition and flow, tool state and Reoloc'cal evaluation; "vionitor the well gas and fluid parameters and perfornri functions auzomatically such as interrupting the fluid flow to the surface, opening or closing of valves when certain acquired downhole parameters such,as pressure, flow, temperature o,- fluid content are determined to be outside the normal ranges stored in the s-,-siems' memory (astescribed below,.,,ith respect to FIGURES 6 and 7); and Provide operator to system and s,,stem to operator interface at the surface using a computer control surface control system. Provide data and control information among systems in the wellbore. In a preferred embodiment and in accordance with an important feature of the present invendoh, rather than using a do,.,.-nhole control system of the type described in the aforernenidoned patents wherein the downhole activities are only actuated by surface commands, the present invention utilizes a downhole control systern which automatically controls downhole tools in response to sensed selected downhole pa=ete-,s without the need for an initial control signal from the surfacc or lom some other exte-nal source. Referring to FIGLRES 2. 3, 6 and 7. this do,,, Tthole comput-er based co=ol system includes a microprcc,--..sor based dara processing 3nd control system 50.

EI,-cwonics control system 50 acquirts and processes data sent frorn the surface as from transceiver syste-m 52 ar.d also trarisrnits do,,,,mhole s,-nsor 1-,lform.ation 1 Lk- as received from the data acquisition system 54 to the surface. Data acquisition system 54 will preprocess the analog and digital sensor data by sampling the data periodically and formatting it for transfer to processor 50. Included among this data is data from flow sensors 56, formation evaluation sensors 58 and electromechanical position sensor 59 (these latter sensors 59 provide information on position, orientation and the like of downhole tools). The formation evaluation data is processed for the determination of reservoir parameters related to the well production zone being monitored by the downhole control module. The flow sensor data is processed and evaluated against parameters stored in the downhole module's memory to determine if a condition exists which requires the intervention of the processor electronics 50 to automatically control the electromechanical devices. It will be appreciated that the automatic control executed by processor 50 is initiated vithout the need for a initiation or control signal from the surface or from some other external source. Instead, the processor 50 simply evaluates parameters existing in real time in the borehole as sensed by flow sensors 56 andlor forrnation evaluations sensors 58 and then autornaticalIv executes 1nructions for appropriate control. Note that while such automatic initiation is an important fearwe in certain situations. an operator from the surface may also send control instructions downwardly from the surface to the n=ceiver system 52 and into the processor 50 for executing control of downhole tools and other electronic equipment.

As a result of this control, the control system 50 may initiate or stop the fluid/gas flow from the geological formation into the borehole or from the borehole to the surface.

X The downhole sensors associated with flow sensors 56 and formation evaluations sensors 58 may include, but are, not limited to, sensors for sensing pressure, flow, temperature, oil/water contenit, geological formation, ga=a ray detectors and formation evaluation sensors which utilize acoustic. nuclear, resistiviry and electromametic technology. It i,ill be appreciated that ty-pically, the pr-essure, flow, temperature and fluid/gas content sensors %,.ill be used for monitoring the production of hydrocarbons while the formation evaluation sensors will measure. among other things, the rr.o,,emc-r.c of hydrocarbons and watc- M th;.. form ation. Thl;-,:, )mpL:er L., (processor 50) may automatically execute instructions for actuating electromechalucal drivers 60 or other electronic control apparatus 62. In rum, the electromechanical dniver 60 will actuate an electromechanical device for controlling a downhole tool such as a sliding sleeve, shut off device, valve, variable choke, penetrator, perf valve or gas lift tool. As mentioned, downhole computer 50 may also control other electronic control apparatus such as apparatus that may effect flow characterisiics of the fluids in the well.

In addition, downhole computer 50 is capable of recording downhole data acquired by flow sensors 56, formation evaluation sensors 58 and electromechanical position sensors 59. This downhole data is recorded in recorder 66. Information stored in recorder 66 may either be retrieved from the surface at some later date when the control system is brought to the surface or data in the recorder may be sent to the t.-,-.isc-.ivesystem 52.and then communicated to the surface.

7he borehole tr=-riiitter/receiver 52 n=fers data from do,,,ole to the surface and receives commands and data from the surface and between other downhole modules. Transceiver assembly 52 may consist of any known and suitable transceiver mechanism and preferably includes a device that can be used to transmit as well as to receive the data in a half duplex communication mode, such as an acoustic piezoelectric device (i.e., disclosed in aforementioned patent 5,2222,049), or individual receivers such as accelerometers for full duplex communications where data can be t=mitted and received by the downhole tools simultaneously. Electrorcs drivers may be used to control the electric power delivered to the nansceiver during data t=mission.

It be appreciated that the downhole control system 22 reqLdres a power source 66 for operation of the system. Power source 66 can be generated 'in the borehole, it the surface or it can be supplied by energy stornge 4 'c Je,,.1 Is such as barteries. Power is used to provide elecm'dal voltage and cu.-r,-nt to the electronics and electromechanical devices connected to a paricular sensor in te borehole. Power for the power source may come from the surfce through haid,.^in'ng or may be provided in t.he borchoie such as by using a turbine. Other power sources include chemical L k, reactions, flow control, thermal, conventional batteries, borehole electrical potential differential, solids production or hydraulic power methods.

Referring to FIGURE 7, an electrical schematic of downhole controller 22 is shown. As discussed in detail above, the downhole electronics system will control the electromechanical systems, monitor formation and flow parameters, process data acquired in the borehole, and cansmit and receive commands and data to and from other modules and the surface systems. The electronics controller is composed of a microprocessor 70, an analog to digital converter 72, analog conditioning hardware 74, dig- ital signal processor 76, communications interface 78, serial bus interface 80, nonvolatile solid state memory 82 and electromechanical drivers 60.

The microprocessor 70 provides the control and processing capabilities of the system. Th.e processor will control the data acquisition, the data processing, and the evalua:ion ofthe data for detem-dnation if it is within the proper operating ranges. The controller %k4111 also prepare the data for ti-ansmission to the surface, and drive the tnarismirter to send the information to the surface. The processor also has the responsibility of controlling the electromechanical devices 64.

The analog to digital converter 72 tr=forms the data forn. the conditioner circuitry into a binary number. That binary number relates to an electrical current or voltage value used to designate a physical parameter acquired from the geological formation, the fluid flow, or status of the electromechanical devices. The analog conditioning hardware processes the signals from the sensors into voltage values that are at the range required by the analog to digital converter.

The digital signal processor 76 pro,,ides the capability of exchanging data with the processor to support the evaluation of the acquired downhole information, as well as to encode.'decode data for =.smitter-.5- '. The processor 70 also provides the control and timing for the diivers 78.

7necommunication drivers 70 arc. electronic switches used to control the flow of electrical power to the =smirter. The processor 70 provides the con=l and timing for the dfivers 78.

II The serial bus interface 80 allows the processor 70 to interact with the surface data acquisition and control system 42 (see FIGURES 5 and 5C). The serial bus 80 allows the surface system 74 to transfer codes and set parameters to the micro controller 70 to execute its functions downhole.

The electromechanical drivers 60 control the flow of electrical power to the electromechanical devices 64 used for operation of the sliding sleeves, packers, safety valves, plugs and any other fluid control device downhole. The drivers are operated by the microprocessor 70.

The non-volatile memory 82 stores the code commands used by the micro controller 70 to perform it-s functions downhole. The memory 82 also holds th.e variables used by the processor 70 to determine if the acquired parameters are in the proper operating range.

It will be appreciated that downhole valves are used for opening andclosing of devices used in the control of fluid flow in the wellbore. Such electromechanical downhole valve devices will be actuated by downhole computer 50 either in the event that a borehole sensor value is determined to be outside a safe to operate range set by the operator or if a command is sent from the surface. As has been discussed, it is a particularly significant feature. that the downhole control system 22 permits automatic control of downhole tools and other downhole electronic control apparatus without requiring an initiation or actuation signal from the surface or from some other e.xternal source. This is in distinct con= to prior art control systems wherein control is either actuated from the surface or is acniated by a downhole control device which requires an actuation signal from the surface as discussed above. It will be appreciated that the novel downhole control system control of electromechanical devices and/or electronic control apparatus is accomplished automatically without the requirement for a surface or other external actuation signal can be used separately from the remote well production control scheme shown in FIGURE 1.

Turning now to FIGURES 2 and 3), an example of the domhole conrxol system 22 is sho%,-n in an enlarged view of well nurr.,,er 2 from platfo,-,, 1 depicting zonets 1. 2 c - whereb,v the r 2-1b and N. Each of zones 1, 2 and N is associated with a downhole control system 22 of the type shown in FIGURES 6 and 7. In zone 1, a slotted liner completion is shown at 69 associated with a packer 7 1. In zone 2. an open hole completion is shown with a series of packers 73 and intermittent sliding sleeves 75. In zone N, a cased hole completion is shown again with the series of packers 77, sliding sleeve 79 and perforating tools 8 1. The control system 22 in zone 1 includes electromechanical drivers and electromechanical devices which control the packers 69 and valving associated with the slotted liner so as to control fluid flow. Similarly, control system 22 in zone 2 include electromechanical drivers and electromechanical devices which control the packers, sliding sleeves and valves associated with that open hole completion system. The control system 22 in zone N also includes electromechanical drivers and electromechanical control devices for controlling the packers, sliding sleeves and perforating equipment depicted therein. Any known electromechanical driver 60 or electromechanical control device 64 may be used in connection with this invention to control a downhole tool or valve. Examples of suitable control apparatus are shoAm, for example, in commonly assigned U.S. Patent Nos. 5,343.963; 5,199,497; 5,346,014; and 5,188,183, all of the contents of which are incorporated herein by reference; FIGURES 2, 10 and 11 of the '168 patent to Upchurch and FIGURES 10 and 11 of the'l 60 patent to Upchurch; FIGURES 11 -14 of the '112 patent to Schultz; and FIGURES 1-4 of patent 3,227,228 to Bannister.

Controllers 22 in each of zones 1, 2 and N have the abiliry not only to control the electromechanical devices associated with each of the downhole tools. but also have the ability to control other electronic control apparatus wE--h may be associated with. for example, valving for additional fluid control. The downhole control systems 22 in zones 1. 2 and N further have the ability to communicate with each other (for example through hardwiring) so that actions in one zone may be used to effect the actions in another zone. This zone to zone cornrilunication co=itutes still another important fearare. In addition, not only can the downhole computers 50 in each of control systems 22 communicate with each other. but the cor- 1 - thr - - ,put,--.s o also h.ave ability (,.;2 transceiver system 52) to cominw. icate ouzhth- -Ok surface control system 24 and thereby communicate with other surface control systems 24 at other well platforms (i.e., platforms 2 or N), at a remote central control position such as shown at 10 in FIGURE 1, or each of the processors 50 in each downhole control system 22 in each zone 1, 2 or N can have the ability to communicate through its transceiver system 52 to other downhole computers 50 in other wells. For example, the do,,,, nhole computer system 22 in zone 1 of well 2 in platform 1 may com. municate with a downhole control system on platform 2 located in one of the zones or one of the wells associated therewith. Thus, the downhole control system permits communication between computers in different wellbores, conununication between computers in different zones and com. munication between computers from one specific zone to a central remote location.

Liformation sent from the surface to transceiver 52 may consist of acnial cont:rol in.formation, or may consist of data which is used to reprogram the memory in processor 50 for initiating of automatic control based on sensor information. In addition to reprogramming information, the information sent from the surface may also be used to recalibrate a panicular sensor. Processor 50 in turn may not only send raw data and status information to the surface through =sceiver 52, but may also process data downhole using appropriate algorithms and other methods so that the ffiformation sent to the surface constitutes derived data in a form well suited for analysis.

Referring to FIGURE 3, an enlarged view of zones 2 and N from well 2 of platform 1 is shown. As discussed, a plurality of downhole flow sensors 56 and downhole formation evaluation sensors 58 communicate with downhole controller 22. The sensors are permanently located downhole and are positioned in the completion string and/or in the borehole casing. In accordance with still another important feature formation evaluation sensors may be incorporated in the completion string such as shown at 58AC in zone 2, or may be positioned adjacent the borehole casing 78 such as shown at 581)-F in zone N. In the larter case. the formation evaluation sensors are hardwired back to control system 22. 7he formadon evaluation sensors may be of the type described above including density, porosity and resisdviry rypes. These sensors measure formation _geology. formation saturation. formation 6p porosity, gas InfitLx, water content, petroleum content and formation chemical elements such as potassium, uranium and thorium. Examples of suitable sensors are described in commonly assigned U.S. patents 5,278, 758 ( porosity), 5,134,285 (density) and 5,001,675 (electromagnetic resistivity), all of the contents of each patent being incorporated herein by reference.

Referring to FIGURE 14, an example of a downhole formation evaluation sensor for permanent placement in a production well is shown at 280. This sensor 280 is comprised of a side pocket mandrel 282 which includes a primary longitudinal bore 284 and a laterally displaced side pocket 286. Mandrel 282 includes threading 288 at both ends for attachment to production tubing. Positioned sequentially in spaced relation longitudinally along side pocket 286 are a plurality (in this case 3) of acoustic, electromagnetic or nuclear receivers 290 which are sandwiched between a pair of respective acoustic, electromagnetic or nuclear transmitters 292. Transmitters 292 and receivers 290 all communicate with appropriate and known electronics for carrying out forr,-iaiion evaluation measurements.

7rle information regarding the formation which is obtained by transi1liners 292 and receivers 286 will be forwarded to a downhole module 22 and transmitted to the surface using any of the aforementioned hardwired or wireless communications techniques. In the embodiment shown in FIGURE 14, the formation evaluation information is transmitted to the surface on inductive coupler 294 and tubular encased conductor (TEC) 296, both of which will be described in detail hereinafter.

As mentioned above, in the prior arT- formation evaluation in production wells wa.s accomplished using expensive and time consuming wire line devices which wa-s positioned through the production tubing. The only sensors permanently positioned in a production well were those used to measure, temperarwe. pressure and fluid flow. In contz-ast. Lie sys" texein perrnane,,if-%, locat,'S formation evaluation se-sors do,,,,-nhol.in the production well. The permariently positioned formation evaluation sensors of the present system will moruitor both fluid flow and. mort, importantly. will measure- formation parameters so that changing conditions in the formation will be sensed before problems occur. For examplc. water in the formation can be measured

31 prior to such water reaching the borehole and therefore water will be prevented from being produced in the borehole. At present, water is sensed only after it enters the production tubing.

The formation evaluation sensors 3.

4.

n z are located closer to the formation as compared to wireline sensors in the production tubing and will therefore provide more accurate results. Since the formation evaluation data will constaritly be available in real or near real time, there will be no need to periodically shut in the well and perform costly wireline evaluations. The multi wel 1/multi zone production well control system may be operated as follows:

1. Place the downhole systems 22 in the tubing string 38.

Use the surface computer system 24 to test the downhole modules 22 going into the borChole to assure that they are working properly. Prozi-am the modules 22 for the proper downhole parameters to be monitored. L-,jw.LI and interface the surface sensors 46 to the computer controlled syRem 5. Place the downhole modules 22 in the borehole, and assure that they reach the proper zones to be monitored and/or controlled by gathering the formation natural gamma rays in the borehole, and comparing the data to existing NfWD orwireline logs, and monitoring the information provided by the depth meas=ment module 44.

6. Collect data at fixed intervals alter all downhole modules 22 have been installed by polling each of the downhole systems 22 in the borehole using the surface computer based system 24. if the Clectro mechanical devices 64 need to be actuated to control the formation ancLor well flow. the operator may send a command to the downhole elecuonics modulle- 50 insnticting it to acruate the electromechanical device. A message s,.ill be sent to the surface from the electronics control module 50 indicating that the co=and was executed. Alternatively, the downhole electronics module -15 Ib '7_ may automatically actuate the electromechanical device without an external command from the surface.

8. Tne operator can inquire the status of wells from a remote location 10 by es-,ablishing a phone or satellite link to the desired location. The remote surface computer 24 will ask the operator for a password for proper access to the remote system.

9. A rnessagC will be sent from the downhole module 22 in the well to the surface sysiem 24 indicating that an electromechanical device 64 was actuated by the downhole electronics 50 if a flow or borehole parameter changed outside the normal operating range. The operator will have the option to question the downhole module as to why the action was taken in the borehole and overwrite &,e action by commanding the downhole module to go back to the original sLarus. The operator may optionally send to the module a new set o.fpara.-,neters &21 %kill reflect the new operating ranges.

10. DurrinR an emergency situation or loss of power all devices w'il rev-,- to a known f,il safe mode.

The production well control system may utilize a wide variety of conventional as well as novel downhole tools, sensors, valving and the like.

Examples of certain preferred and novel downhole tools for use in the system of the present invention include: 1.

6 a retrievable sensor gaup- side pocket mandrel: subsurface safery valve posidon and pressure -noru'torin,c remotely controlled inflai,or,,defladon device pressure monitoring; remotely actuated dow-nhole tool siop sv5em-, remotelv conrrolled fluld.',zas control sysiem. =.4 remotely controlled variable- choke and s%.sz;m 7he foregong lisied tools.,1v-ill nos be described to FIGUPjES 8 1 -, Retritv2ble Pressure Gaul: V1 ze Side Pocket Mandrel 'th Induct'%z, Coupler Tnditional permanent do%.,-nhol,- enuze (c.c. sensor) require the 33 oa presswe gauge exe,-nal to the p,-oducz or, tubing thus making the gauge an integral part of the tubing string. This is done so that tubing and/or annulus pressure can be monitored without restricting the flow diazneter of the rubine. However, a drawback to this conventional gauge design is that should a gauge fall or d.rift out of calibration requiring replacement, the entire tubing string must be pulled to retrieve and replace the gauge. An improved gauge or sensor construction (relative to the prior art permanent gauge installations), is to mount the gauge or sensor in such a manner that it can be retrieved by cor-.-non vdreline practices through the production tubing without restricting the flow 7his is accomplished by mounting the gauge in a side pocket mandrel.

Slide pocket mandrels have been used for many years in the ol Lrldustry to a convenient means of retrieving or changing out service devices needed to be provi in close- iroxL-niry to the bottom of the well or located at a particular depth. Side pocketmand.rels perform a variety of functions, the most common of which is allowing Ras Lo,-n the annulus to communicate Aizh oil in the production tubing to lighten it for e.iha.nc,-,4i production. Another popular application for side pocket -ra.-iclr,-s is the chernicall injection valve, which allows chen-Licals pumped from the surface, to be introduced at strategic depths to mix with the produced fluids or gas. These chemicals inhibit corrosion, particle build up on the I.D. of the tubing and many other functions.

As mentioned above, permanently mounted pressure gauges have traditionally been mounted to the tubing wlich in effect makes them pan of the tubirig. By utilizing aide pocket mandrel however, a press= gauge or other sensor may be installed in the si pock.-t-,nakLig it possible to retrieve when necessary. This novel mounting method for a press= gauge or other downhole sensor is shown in FIGURES 8 and 8A. In FIGURE 8, a side pocket mandrel (similar to side pocket mandrel 28-2 in FIGURE 14) is shown at Soand includes a pdrr,=-,. tL-ou& 'Cort. 88 and a la,:!-211,. J115placed side pocket 90. Mandrel 86 is Llireadably corLiec',cd to the production rucing using threaded connecdon 922. Positioned in side pocket 90 is a sensor 94 which miv comprise any suitable transducer for measuring flow. pressure, temper-anwe or the like. In FIGURE S a pressure.'tempcrnrurctransducer 94 (Model or 2250A 34- --'0 1 30 1 commercially available from Panex Corporation of Houston, Texas) is depicted having been inserted into side pocket 90 through an opening 96 in the upper surface (e.g., shoulder) 97 of side pocket 90 (see FIGURE 8A).

Information derived from downhole sensor 94 may be transmitted to a downhole electronic module 22 as discussed in detail above or may be transmitted (through wireless or hardwired means) directly to a surface system 24. In the FIGURES 8 and 8A embodiments, a hardwired cable 98 is used for transmission. Preferably the cable 98 comprises tubular encased conductor or TEC available from Baker 011 Tools of Houston, Texas. TEC comprises a centralized conductor or conductors e,ncapsulated in a stainless steel or other steel jacket with or without epoxy fillLing. An oil or other pneumatic or hydraulic fluid fills the annular area between the steel jacket azd the central conductor or conductors. Thus, a hvdmulic or prieurnatic control IL-ie is obtained which contains an electrical conductor. The control line can be used to conve..,, pneumatic pressure or fluid pressure over Iona dismncl-s'With the electrical insJated wire orwires utilized to convey an electrical signal (power and/or data) to or frorn an insirument, pressure reading device, switch contact, motor or other electrical device. Alternatively, the cable may be comprised of Center-Y tubing encased conductor wire which is also available from Baker Oil Tools. This latter cable comprises one or more centralized conductor encased in a Y-shaped insulation, all of which is further encased in an epoxy filled steel jacket. It will be appreciated that the TEC cable must be connected to a pressure scaled penetrating device to make si_=al transfer with a3uge 94. Various methods including mechanical (e.g., conductive), capacitive, inductive or optical methods are available to accomplish this coupling of gauge 94 and cable 92. A preferred method which is believed most reliable and most likely to survive the harsh downhole environment is a known Ulductive coupler" 99.

Transmission of electronic signals by means of induction have been in use for mally V= most commonly by trarisformers. Transformers are. also referred to as inductors, proside a means of =s,-ritting electrical curr-, nt,,,ilhout a physical connection by the terminal devices. Sufficient electrical current flowing through a coil of e.Li Induce- ' Ilk.e. current in:x second coil ver.' clese proximity to the i -? 0 firs,. -Fre drawback of this tipe of transmission Is that efficiency is low. A loss of power is expenenced because there is no physical contact of conductors; only the influence of one magnetic field in the source coil driving an electric current in the second. To achieve com. rnunication through the inductive device 99, an alternating current (AC) must be used to create the operating voltage. The AC is then rectified or changed to direct current (DC) to power the electronic components.

Much like the inductive coupler or transformer method of signal ti=mission, a very similar principle exists for what are known as "capacitive couplers". These capacitwice devices utilize the axiom that when two conductors or poles in close proxirni- -L-. to each other are charged with vollcages or potential di5.er-Inc.-s of opposite polariry, a cur-,,-nt can be made to flow through the circuit by influencing one of the poles to 'become more positive or more negative with respect to the other pole. When the process is repeated several times a second,. a frequency is established. When the frequency is high enough, (several thousand times per second), a voltage is generated 11 across" the two poles. Sufficien. voltage can be created to pro,de enough power for microprcc--ssL-a and digital circuitry in the downhole instruments. Onc.e powered up, the downhole device can tr-dnsmit; radio- metric, digital or time shared frequency n-ains which can be modulated on the generated voltage and interpreted by the surface readout device. Thus, a com. munication is established between downhole device and the surface. As with inductive devices, capacinve devices can suffer Line loss through lonR lena-ths of cable if the cornimunicadon frequency is too hi-ah causing the signal to be artenuated by the inherent capacitance of the cable itself. Again, as with the inductive devic-es, capacitive devices must use the alternating current (AC) method of trammission with rectification to DC to power the electronics.

By n-a.,--srnitting beams of light through a glass fiber cable. clecroric devices can also c=unicate with one another usr., a light beam as a zonductor as opposed to a solid rr.-L-d conductor in conventional cable. Data =srnission is accomplished by pulsi-cg t,- lleht beam at the source (surfac.- rstr=ent,,vhich is by an end devlc-- (do,,nhole insw=ent) which the pulses and hem into 3 L.

Conductive or mechanical coupling is simply making a direct physical connection of one conductor to another. In the side pocket mandrel 86, a conductor is present in the pocket 90, pressure sealed as it penetrates the body of the side pocket and mated to an external device to transmit the signal to the surface (i.e., solid conductor cable, wireless =sceiver or other device). Tle hard wired coupler may exist in any form conducive to proper electronic signal transmission while not compromising the pressure sealing integrity of the tool. Tle coupler must also be capable of surviving exposure to arsh downhole conditions while in the unmated condition as would be the case when ar in-strument 94 was not installed in the pocket 90.

7he::1,-,-fer-red inductive couz)ler 99 is connected to TEC cable 98 using a pressure sealed connector 95. With the gauge or other sensor 90 being internal and exposed to the I.D. of the tubing 88, and the cable 98 being external to the mandrel 86, but exposed to the annulus enviro=e,---, Lilie connector 95 must penetrate the mandrel pocket 90 allowing gauge 94 and cable 98:o be mated. Due to pressure differences between the tubing I. D. and the annulus, connector 95 also provides a pressure seal so as to prevent communication between the mandrel and annulus.

An ele-ltronic monitoring device 94 which is "landed" in side pocket 90 of mandrel 86, includes a latching mechanism 101 to keep sensor 94 in place as pres=e is exerted on it either from the interior of the mandrel or the annulus side. This latching mechanism 10 1 also provides a means of being unlatched so the device may be retrieved. Several methods exist to accomplish this latching, such as using specific profiles in pocket 90 that align,,ith spring loaded dogs (not shown) on the sensor device 94. Once aligned. the springs force the locking dogs out to meet the profile of the pock-It 90 providing a lock, much like tumblers in an ordinary household key operated lock. This locking action prevents the sensor tool 94 from bleing dislodged fron tsland" c, seat. Tilis is important as any movement up or do,-,1 could cause 1 Ln_ misaligriner,c and impair the integriry of the electronic coupling device 99 to which the sensor tcol 94 is now mated.

317 The latching mechanisrn 10 1 must be of sufficient robustness as to be able to withstand several landing and retrieval operations without comprising the integrity of the latching and release properties of sensor tool 94.

As mentioned, pressure _ji; should be ma'ntaned to keep the mandrel in isolated from the annulus. When the sensor tool 94 is being landed ' Docket 90, it should activate or deactivate pressure sealing device 95 to expose the sensing portion of the sensor tool 94, to either the mandrel or annulus. Similarly, when sensor tool 94 is retrieved from pocket 90, it must also seal off any pressure port that was opened dLirnR t.',-e larding procedure.

-A7,-,e pressure porting mechanism is capable ofbeing opened to eithCr the annulus or the mandrel. T"ne selection device can be, but is not to, a specific prof-711e to the outer housing of the sensor tool 914 co-nbinel-',sit:,] diffe-Crit of locking/actuatirig dogs to: open a sliding s.,.ng in7o a dedca,,,-d pressure:)o,- displace a piston or any s,,,t-,ble co,-ifi-aui--1..lon c. 4l'1Dr-Iss.-.-, port oplening or ciosinz devices. Oncle activadrig the selected por, a pos'.L;,,e seal must-e ma.inta,-.-d on the unseleczed pori to prevent leakage or sensL'nR of an undesired condition (pressure, flow, water cut etc.) while in the unmated condi'lon as would be the case when an instrument was not installed in the pocket.

Subsurface Safety Valve Position and Pressure Monitoring Sys-, m Refe=g to FIGURE 9, a subsur.-^ac-e safety valve position ar,%-: pressure morutoring system is shown generally at 100. System 100 includes a valve housing 102 which houses a downhole valve such as a shut-in valve 104, VW'10US "ressIdr-e and positioning pa=eters of shut-in valve 104 are deterInL'rled tL-oLeh the intlerraction of five sensors which are preferablv tied to a sinRie electrical sL"núii-1 corducto: or multi conductor line (e.c., the aforementioned 7EC cabll-). Thesle s.-rj,,rs rl- -note, morutor dh.e c,-ltlcal pressures and, posizions to remotely controlled subsurface S-Ifer', valve oper2 Tric L405nho'ic- 5,-:,-sors clule four pressure sensors 106, 108, 110 and 112 and one proxirnir\ s,-nso-, 11 _', Pressure sensor or =sducl-r 106 is positioned to sense tubing prl,ssur-, upst:cxn of s'- Lt-1r, valve 104.

1 1 1 i 1 '. [C P.'.,ssurz-, from Pressure tran.,;du,:cr 1 OS is POYsit L).--ed lo "le II. dr3ul..1 hydraulic control-line 116. Pressure transducer 110 is positioned to sense the annulus pressure at a given depth while pressure transducer 112 is positioned to sense the tubing pressure downstream of valve 104. Proximity sensor 114 is positioned external to the valve or closure member 104 and functions so as to enable confirmation of the position of the valve 104. Encoded signals from each of the sensors 106 through 114 are fed back to the surface system 24 or to a downhole module 22 through a power supply/data cable 118 connected to the surface system 24 or downhole module 22. Alternatively, the encoded signals may be =rritted by a Wireless t=mission mechanism. PreferablY cable 118 comprises tubing encapsulated single or multiconducTor line (e.g., the Jorementicned TEC cable) which is = external to the tubing s"...arn downhole and serves as a data path between the sensors and the surface control systern.

A dov,-rlole module 22 may automatically or upon control signals sent Eom the surface. a downhole control device to open or shut valve 1 0.!'.mased, on input frorn the do,--hole sensors 106 through 1 l4I.

7ne for-,,,oina subsurface valve position and pressure mortorL-ic systern provides many fearures and advantages relative to prior art devices. For example, the present invention provides a means for absolute remote conf=ation of valve position downhole. This is crucial for conEdent through tubing operations wireline or other conveywrice means and is also crucial for accurate diagnosis of any valve system malfmcdons. In addition, the use of the subsurface safery valve position and prIessure.

morutonrR sysLern of this invention provides r----J time surface corLfnr. ation ofiproper pzessure condijons for fail-sdae operation in all modes. Also, ths sv,-,,- m provides a mea.-Ls for detl,-nunation of changes in conditions which could r-ender The safery sysil-rr. "..,loperatl,,.e. under adverse or dis=er conditions and. the present invention ides a rr,,-= for surface conf=atior of proper valve equ. - tion 13 ' prov 11 1. za rIC7 to reoperung. downhole valve closure.

Rernoteb.. Ccnrrolled Inflation/Deflation De.ic,, ith a Pr,-ssure '\, loritorir,7System R, now t o F 1 G LTRE 10. a r.. i z-,o p:oc esso r b ased Jc v te c r rn o ni t o 'In - o 1o015 is Intlition of 'h! I- 3 MICropricessor ba-sed device can be actuated either automatically by the doWT1hole control module 22 or the downhole control module 22 may actuate the present device via a surface signal which is u=mitted downhole from the surface system 24. In FIGURE 10, the inflatable element (such as a packer) is shown at 124 and is mounted in a sultable mandrel 126. Associated with inflatable element 124 is a valve housing 128 which includes an axial opening 130 having a f= diameter and a coaxial cavity 132 having a second diameter larger than the first diameter. Also within valve housing 128 is a motor 134 which actuates appropriate gearing 136 so as to provide linear translation to a shaft 138 having a piston-type valve 140 mounted to ore end thereof. As shown by Che arrows in FIGURE 10, motor 130 actuates L7earLna 136 so as to move piston 140 cerween a closed or shut-off position in which piston 140 resides completely in axial openirg 130 and an open position wherein piston 140 resides vrlzhL- i the central caviry v.2 132. A-dal opening 130 terminates Ln dic i.-,iterior of val hous-c- 128 at an InflatIon:o.- ', 42 through which fluid Lro=i an inflation fluid sozc-. 1 en-cers and exils;,n:-'-C o'lvalvC housing 128.

2e irif,adorj.'d-_flau'on device 124 is remotely controlled and/or morlitored LisLng a plurality of sensors in conjunction with a microprocessor based controlle7 146. Of course controlle: 146 is analogous to the downhol.- modules 22 discussed in weat detail above in connection %Yith for example, FIGURES 6 and 7.

:k icroprocc or concoller pair of pressure transducers c r-,,rnunicate iLh rr ss 146. Ont- or-essure =sducer is shovm at 143 and resides the ca,,-ir,, 1 '2 houslilca 128. The second pressure =.s,-Jucer is so,,-n a:150 and -tsid-- s in the yer. 142. In addition, a pair ok' z--oce-atng serscr-s52 and 154 a:e:: 0S1 t c ne benv1- c r v alve ho u_s i ng 12 8 M. 'Do!-I pow t: ir.-, da:-, we s u 1 led, o co r, wo 1 7 U Zh 22 C rO c 2, t a"' i J 1 a a 33, nis C2b1C;S TIEC cible a'-c Power rnay ilso be supplIed by batitl-'es or ihd Ja13 rnall. be me,.hods.

1 k10 It will be appreciated that the scaling device functions as a valve and serves to positively open and close the inflation fluid passage thereby permitting movement of inflation fluid from the fluid source 144 to the sealing element 124. In the particular embodiment described in FIGURE 10, the valve 140 operates by axially displacing the sealing element 124 between the two diametrical bores within the fluid passageway by way of the motor gearing mechanism 134/136 all of which is driven by the on-board microprocessor 146. Valve 140 has two functional positions i. e., open and closed. Of course, the valve could function in alternative manners such as a solenoid. The electronic controller 146 serves to integrate the pressure inputs from pressure transducers 148 and 150 and the proximity inputs from proximity sensors 152 and 154 along with the data/control path 156 to appropriately drive the control valve mechanism during tool inflation. Thereafter, the sensors 148, 150, 152 and 15.4 serve to ensure pressure integrity and other tool position functions.

The remotely controlled inflation/deflation device offers many features and advantages. For example, it C1Lminates the present standard industry design for pressure actuated shear mechanisms which are subject to wide variations in actuation pressures and premature inflation.

1 provides a directly controllable mechanism for initiation of do,,,,nhole tool inflation and through the unique self cleaning inflation control valve configuration shown in FIGURE 10, obsoletes present design configurations which are subj ect, to fouling by debris in the inflation fluid. In addition, it enables direct control of closure of the inflation valve whereas in the prior art. spring loaded and press= actuated designs resulted in press= loss during operation and unreliable positive sealing action. The use of a motor driven. mechanical inflation control valve also cor-dtutes an important feanire Still anoLer f,-2rw,-.

is the incorporation of electroruc proximity sensors in-,. 1 lation to inflatable tools so as to ensure correct positioning of selective inflation tools. High angle/horizontal orientation of inflatable tools requires conveyance of infladon tools via coil nibin. which is subject to substantial drag. In contrast to the presdrit systm the pn'o.,.iri b,.is been limited to positioning oflinflation tools by colic: t-,-pe Cvic.-s or 4-1 i 0 pressure operated devices, both of which were hJghly unreliable under these conditions.

The use of a microprocessor in conjunction with an inflatable downhole tool and the use of a microprocessor based system to provide both inflation and deflation to control the downhole tools also constitute important features. Tle present systú!rn thus enables multiple, resettable operations in the event that procedures may so require or in the event of initially incorrect positioning of tools witEn a wellbore.

Finally, the present system. provides a continuous electronic pressure monitoring system to provide positive, real tirne wellbore and/ zonal isolation integrity downhole.

Remotely Actuated DowTffiole Tool Stor) Svstern Referring to FIGURES 11 A and 11 B, a remotely actuated tool stop is shown generally at 160. In &e embodiment shown, the remotely actuated tool stop L-cludes a side pocket mandrel 162 having a primazybore 164 and a side bore 166. A tool stop 168 is pivot211.v mounted onto a threaded shalt 170 with shal-, 170 beine sealed by seal 172 to prIevent the flow offluid or o&.e,- debris into sidebore- 166. Threaded shaft 170 is connec, .ed to a holddown 174 which in ram, is connected to appropriat.c c-laring 176 and a motor 178. Waile motor 178 may be powered by a variety of known means, preferably an Linductive coupler 180 of the type described above is used to power the motor through a tubular encased conductor or TEC 192 as described above. Not- that a pressure relief port 184 is provided between sidebore 166 and primary bore 164.

7he foregoing system described in FIGURE 11 A functions to provide a remotely actuated device which positively limits the downward rnovement of any tools used wthin the wellbore. A primary utilization of the tool stopincludes use as a positioning device at close prox="ry (i.e. below) to a tool, for example or the side pocket m=drel 162. The System ma.v also be used other difficult to local- Clevices in high angle or hor.zor..,.-, Ln whe- activated as shomm in FIGURE 11 A, the surface ope.-2ior rnay proceed dowriveird a work sting undl conLict is made "ith tool siop 163. The tools and. or work szdng beng delivered do,-nhole may then be pulled back up a known dis,.ince thus ensuring proper posLiloninz to perform die intended 1.9 the irc!etcd rec.-.c)t:iclc.-k.n jitemative M, &jr 1 fiinction would be as a general purpose safety device, positioned close to the bottom Of the tubing string in the wellbore. The tool stop system would then be activated whenever wireline or coiled tubing operations are being performed above and within the wellbore. In the event that the work string or individual tools are accidentally dropped, the tool stop, ensures that they are not lost downhole and provides for easy retdeval at the tool stop depth. After through tubing operations are concluded, the tool stop system 'is deactivated/retracted as shown in FIGURE 11 B to provide a clear tubing bore 164 for normal well production or injection. It will be appreciated that during use, motor 178 will actuate gewing 176 which in turn will rotate threaded shaft 170 so as to raise tool stop 168 to the position shown in FIGURE 11 A or lower (deactivate or vithdraw) tool stop 168 to the retracted position shown in FIGURE 1 IB. The motor vill'ce dictall-,, controlled by a-,i ei.--,trorucs control module 22 provided in inductive coupler section 180. Control module 22 can either be actuated by a sudace. or e.,c.,emal con"-ol si=al o.- may be i. 1.'. --- ' 1 - auto a actuated do"mhole'.:)ased en as above "i7I regard to FIGURE 7.

7he remotely actuated tool stop offers many feaures and advartages including a means for sel,-cdve surfac-- actuation of a downhole device to prevent tool loss; a means for wiectiv.- surface actuation of a do,,,.-a.ole device to provide for positive tool location downhole and as a me= to r)-,.ven. acc".,d,-nta.' impact d-i-rnaz^. to sensitive tools downhole such as submr.-:ice vaIves and 1 - irlflatable,ubra plugs.

1Zernot,-1! Con olled Fluids/Gas Control Svstcn, R.-;-r:rg now to FIGURE 12, a rtnottly controlled is ide pock--, -,rand=. 1 a a W.d a ar.-' Lncludes a si in =.

bort 194. L,-clf--d sld-, 'Cort 194 is a r:-r.o%.ablz- flov; Tbjs tio.v zo,-.=.01 devict 196 %.--,'ch is artached to a ttiescopic secdon 1 9S followei by a gas r--gtJator sectien 2(,o. 3 tu;,4. regulator section 202. a gew section 20-4 rlocor 200 Is JLn i-t- 3 se,,,,lorj 210, 2 12 and 2 14 retain the flow control assembly wchin he side bore or side pocket 194. Upon actuation by electronics module 208, control signals are sent to motor 206 which in turn actuate gears 204 and move gas regulator section 200 and fluid regulato - r section 202 in a linear m=er upwardly or downwardly WIthin the side pocket 194. This linear movement will position either the gas regulator section 200 or the fluid regulator section 202 on either side of an inlet port 216.

Preferably, electronics control module 208 is powered and/or data signals are sent thereto via an inductive coupler 218 which is connected via a suitable electrical pressure fitting 220 to the TEC cable 192 of the type discussed above. A pressure t-a.-.sduce,- 224 sewes pressure Lri the side pocket 194 and communicares '"'-e serjed pressure:o the electronics control module 208 (which is arialoeous to downhole module 22). A pressure relief port is provided to side pocket 1914 in zhe area surrourdLie electronics module 208.

12 provides for:.-zulajo.71 of i.-,-,,7,,ow control assembly sho,,,,-n in FIGU 1 wdlo?- gas flow from the wellbore zo:he rlbliccasina a.7-ijlus or ve-sa.

Fiow cc,-,z:oi is exercised by separate fit,;d and gas 'flow regula,,,--, r wiGnin the de,,,1c.-. Encoded data/control signals are supplied either exi- ernally from the surface or subsurrface via a data control path 222 and/or internally via the int.- .-acdon of the presswe sensors 224 (which are located either upst-cam or do"=ea-n in tne tubinga conduit and in the =ulus) and/or other, appropriate sensors togethe. '-', e on-board =.ic,-opr,--cewor 208 in a manne,-idseussl-d alcove with regard to FIGUIRES 6 and 7.

-7hr flow control assembly provides for, rwo and diszi.:,cr, sub:r,-5.-rns, a respective iuid a7,LI g2.s tlow szrearn re 'idor.. Th-se 911-1 art- pr--ssure-ituid isolated and art- contained With tht ass,- b 1v. Eac h o f r-h c syst. - r-ns 1 S z o n=-, c d fo r th'. S p- c -, If 1 c rt S-, e re me n z s o C I'I o w z,3 n an d r 5; 5 =.,::t ', o 3 12 C. c!.' the co,-,zol mediturns. kx--d rcc".crocal".0r, motor:,j6 and Sew assembly 204 aS weil 3S G'IC telescoolc 2=;L5 posti.o--;-g o."the ippropnat-- tu".dA or gas subsvstz!rn. n the :is PASS.2,'C5 In[o ind out 5,-4c S;:-,-CS as r_ 4. Lt- the mounting/control platform for the valve system downhole. Both the fluid and gas flow subsystems allow for fixed or adjustable flow rate mechanisms.

The external sensing and control signal inputs are supplied in a prefeTred embodiment via the encapsulated, insulated single or multiconductor wire 222 which electrically connected to the inductive coupler system 218 (or alternatively to a mechanical, capacitive or optical connector), the two halves of which are mounted in the lower portion of the side pocket 194 of mandrel 190, and the lower portion of a regulating valve assembly respectively. Internal inputs are supplied from the side pocket 194 and/or the flow control assembly. All signal inputs (both external and internal) are supplied to the on-board computerized controller 208 for all processing and distributive control. In addition to processing of off boards inputs, an ability for on-board storage and manipulation of encoded electronic operational "rnod..Is" constitutes one application of the present system i providing for autonomous optimization of many pa=eters, including supply gas utilization, fluid production, annulus to tubing flow and the like.

-ne remotely controlled fluid/gas control system describ e-cl eliminates known prior art designs for gas lift valves which forces fluid flow through gas regulator systems. This results in prolonged life and eliminates premature failure due to fluid flow ofFthe gas.regulation system. Still another feature is the abiliry to provide separately adjustable flow rate control of both gas and liquid in the sing-le, valve. Also, remote actuation, control andlor adjustment of downhole flow regulator is provided. Still another feanim, is the selected implementation of two devices within one side pocket mandrel by axial manipulation/displacement as described above. Still another feature the use of a motor driven. inductively coupled de,,ice in a side pocket. The device reduces total quantin, of circulating devices in a gas lifl: svell b..

prolonging circulating mechanism life. As rrientioned, an importarit fearwe of this system is the use of a microprocessor 208 in conjunction with a do;ole gas liftregulation device as well as the use of ani,:roprocI-ssor in conjunction with a do,,nho[l- liquid control device is 4-,< Remotely Controlled Variable Choke and Shut-Off Valve Svsiem Referring to FIGURE 13, a remotely controlled downhole device is shown which provides for actuation of a variable downhole choke and positively seals off the wellbore above from downhole well pressure. This variable choke and shut-off valve system is subject to actuation from the surface, autonomously or interactively with other intelligent downhole tools in response to changing downhole conditions without the need for physical reentry of the wellbore to position a choke. This system may also be automatically controlled downhole as discussed with regard to FIGURES 6 and 7. As will be discussed hereinafter, this system contains pressure sensors upstream and downstream of the choke/valve members and real time monitoring ofthe response of the well allows for a continuous adjustment of choke combination to achieve the desired wellbore pressure parameters. The choke body members are actuated selectively and sequentially, thus providing for wireline replacernen- of choke orifices if necessary.

Turni g to FIGURE 13, the variable choke and shut offvalv1- system includes a housingg-230 having an axial opening 232 therethrou&.. Wifflin 0 0 - axial opening 232 are a series (in this case two) of ball valve chokes 234 and 236 which are capable of being actuated to provide sequentially smaller apertwes; for example, the aperture in ball valve choke 23)4 is smaller than the relatively larger apernire in ball valve choke 236. A shut-offvalve 238, may be completely shut offto provide a full bore flow position through axial opening2232. Each ball valve choke 234 and 236 and shut-off valve 238 are releasably engageable to an engaging gear 240, 242 and 244. respectively. These engaging gears are attached to a threaded drive shafl 246 -and drive shaft 246 is attached to appropriate motor gearing 248 which in rurn is attached to stepper motor 230. A computerized electronic conn-oller 252 provides acruation control signals to stepper motor 250. Downhole con-collcr 252 communicates with a p=' of pressure transducers, one =ducl-r 254 being located upstream of the ball valve chokes and a second pressure =ducer 256 being located downstream of the ball valve chokes. Nlicroprocessor controller 252 can commun"cat,- the surface either by.'lreless means of the npc deschibed In deia'tl abo.,.,- or. as shown in r i i 1 Lt-(, IFIGURE 13 by hard wired means such as die Power/dala supply cable 253 wuch is preferably of the TEC type described above.

A-s shown in FIGURE 13, the ball valve chokes are positioned in a stacked config=don within the system and are sequentiallY actuated by the control rotation me-,harusTn of the stepper motor, motor gearing and threaded drive shaft. Eachball valve choke is configured to have two functional positions: an "open" position with a fully open bore and an "acruated" position where the choke bore or closure valve is introduced into the wellbore axis. Each member rotates 90 pivoting about its respectIve central axis into each of the two fi,.,-ict;onal positions. Rotation of each of the rr.e,-nbe.-, is accomplished by ac-mation ofthe. stepper rriotor wich acruares the motor gew.r.ú: in = d-rives the threaded d:v-shaft 246 such that &.e engaging gears 2410, 24.2) or 2-4 Y,ill engaze a re=ective ball valve choke 23-4 or 236 or valve 23) 8. by the el, e-l-jonic c o ntro Ille: 2 52 rr av be based. irl r)a:-, . ucc. Z RS 254 and 256 or, cv a control sizna,:5o-n -L- choke and of th-1 u:cvldes fe-t:=--s and advantapes L'ncl.,dn7- a novell, r.neans for ZI.C ac-,-,-, 1101-, ofa do,iol.- adjustable choke as well as anovel means for installation remotely or z.teractively controlled do"-,irol. chokes and shut-off valves!o provide.

tur,.edic)cdm,---7td wellbore performance.

Ln an alternate consLuction.

ide pcc.<t-c 290 is or;cntl.d jcs.."de zz.

re,c77z,z to F:0LTRES 1 SA-D, a si cony -non-,,: side pockets. In oihe, woris. -ate- Lai r_he 5;de -ecke:

ope:'-'rlg 296 the side pocket 296 is onen:,-d tht- side pocket sT%crur-x, :robl,!m 0 f silt,nt c 5,K;I, a c cr t z 2: i normaliv 0 s j, z the croduc 'on to th th, Oce- -0nD;scn crob s---sos since _sors and s rIiz:j o z.

n 5, 1 0 h:: 0 c n 1-11 0 onc-- o sensor's rtc.mo.,td. Che sil' v. -nlc nt 9 9 Chu 7-, c,,.. j n.

c o 7 1 1 _)o n 1 -10 k-1 -?0 ho,,ve.,.c.-, pocket 296 does not become occluded with silt since falling or sertling panicles fall down the production tube and are not collected In the pocket 290. Moreover, any silt flushed into pocket 290 will settle back into the production tube via do,..,-n angled section 297 thus maintaining the pocket opening 290 in a clear condition. Becaus-- of the clearer condition of the pocket, changing of sensors is simplified. In other respects, the pocket 290 is the same as the other embodiments discussed herein. It is capable of supporting all of the sarrie sensors in equivalent positions (albeit upside down) and merely provides the added benefit discussed herein.

in addition, the side pocket 290 is particularly adapted to receive aa,u,,zei-.- duez; coupler 3) 10 (FIGURE 15C). Gauge counler 3 10 is, in co=-,,-cial form, available from Panex Corporation,- Sugarland Texas and is protected unde.- U.S. Patent No. 5,457,988 and 5,4155,573 the entire disclosures of both of which are incomor-ated herein by reference. The inductive couple is composed of female coupler 348 and male inductiVe coupler 349.

As wIll be clearly understood b.,. on, of skill in the ar-.:7om a uerisal of FIGURIE:S 1 5A-I), the side pocket 290 depends from main bore 28 8 siMilarly to those em'ood-,nents hereinbefore described, however being oriented upside down. The side pocket 290 ofthe invention includes a relatively broad shoulder area 312 having a th.rou&, bore 3 13 adapted to sealingly receive a connector assembly 336 which inductively, or alternatively conductively, co=unicates wri-1 a sensor or gauge 3 18 discos,-,-- within side pocket 290. Side pocket 290 is defined by said shoulder =a 3 12 and an outer wall 330 and inner wall- 331 Inner wall 332 extends a shorter distance than &,.- endre extent of side pocket 290 so as to expose latch 320 of gauge ^) 18. Latch 3 1 - lower end of Le side pocket 290, and 320 provides the triple flinction of sealing th, p'd' 1 rovi. --ie a s--ucrure to maintain the sensor in the side r)ocker and also is adapted to engage 2 tool for when the ser.-zor;s changed. Seal 334 is o'i r-,CL-J-to- metal an_. Dreverits primu-,,. bore tluld &on,---washing-the sidlc pocke, w.d s; nsor. This is ad., =n-eous because it reduces L c - 1 he components.z h 3'0 includes doRs 322 an-1 324..hich are in a recessed posit'Lon during installl:;o,-i gaup- S but cx,;-n,A 3-16 and 32S upor, of the senso-r 1-, a maw.cr. One-- f Lt- 1 the dogs 322, 324 are engaged with recesses 326 and 328, the sensor is secured in the side pocket. in order to remove the sensor from the side pocket, a removal tool (not shown) is run below the side pocket; next a kickover tool (not shown) is employed to push the removal tool over into the side pocket so that engagement with the latch is possible; ajerk upward to release the dogs and ajerk downward to withdraw the sensor is all that is nece. The sensor can then be moved along in the primary bore 288 as desired. Inner wall 332 also includes a port 333 to allow pressure from the primary bore to reach the sensor or gauge 318. 71e port does not create any risk of "washing" but does as is known to one of skill in the art allow pressure to be read by the sensor or gauge. Also importantly, side pocket 290 is maintained in a parallel relationship to main bore 288 as opposed to some prior art side pocket mandrels where side pockets are positioned at an angle to the main bore. The arrangement provides the advantage of a smaller overall diameter than the prior art. This allows entry into smaller identified boreholes and thus is clearly beneficial to the indwrry.

Also beneficial are the metal-to-metal high pressure firtingas 338 and 340 which are disposed, one on the surface connection assembly 336 (338) and one in the throughbore 3 13 (3)40). The metal-to-metal fittings provide an excellent higgh pressi= seal wWch has proven extremely reliable. The seal is aided by o-rings 350 and 35 1.

The arrangement is advantageous not only for the reasons discussed above but because it enables easy exchange of surface connection assemblies.

while preferred embodiments have been shown and described. modifications and substitutions may be made thereto,,,ithout departing from the scope of the in,,ention. Accordingly. to be understood that the presCrit invention has been describe"' by way of illustrations and not I'Lmitation.

Claims (4)

\-hat is claimed is: Le- CLAIMS:

1. A downhole sensor comprising:

a side pocket mandrel having a primary bore and a laterally offset side pocket.

a removable downhole sensor residing in said side pocket; an opening through a shoulder defined by an upper surface of said side pocket for receiving a sensor connector; and said sensor connector operable to provide capacitive, inductive or optical coupling with said sensor.

2. A downhole sensor as claimed in claim 1, wherein said sensor connector includes a male inductive coupler adapted to be received by a female inductive coupler within said sensor in said side pocket to provide an inductive couple between sa--'d sensc-l- connector and said sensor.

3. A downhole sensor as claimed in claim 1, wherein said opening in said shoulder includes a first side of a metal-to-metal seal and said connector includes a second side of the metal-to-metal seal and wherein the first and second sides are adapted to mate to form a high pressure seal.

4. A downhole sensor as claimed in claim 1, wherein said side pocket is disposed in parallel with said primary bore.