GB2182180A - Electronic control system with fiber optic link - Google Patents

Abstract

In a system for monitoring and control of servicing units for pressurized petroleum production wells, a plurality of operating parameters are monitored by transducers and controlled by remote operators. The transducers and operators are connected by an equipment comlink and full duplex fiber optic link to one or more control comlinks located at a remote location. A control panel indicates information from the control link stored in output registers with respect to the conditions in the servicing unit and changes data stored in input registers with respect to the desired operating conditions both of which are communicated through the control comlink and the fiber optic link. <IMAGE>

Description

SPECIFICATION Electronic control system for well servicing equipment The invention relates to servicing equipment for petroleum production wells and, more particularly, to an electronic monitoring and control system incorporating a fiber optic linkforequipment employed in the servicing of pressurized petroleum wells.

The petroleum services industry may be divided into three general areas: exploration, drilling and production. The problems encountered in each area and the technologies developed to address the problems of each area are often quite distinct. For example,thetime required to perform a given job while drilling a well is more significant than in exploration due to the enormous costs of meon and equipment required fordrilling. Similarly,the risks associated with explosive and combustible fluids and gases are greaterwhile servicing a well in production than while drilling. The monitoring and control of equipment in each field ofthe petroleum services industry is designed with the particular needs and risks associated with thatfield in mind.

The servicing of a petroleum production well may be performed either while the well is under production pressures or after production flowfrom the well has been terminated by the injection of kill fluidsintothewelltostoptheflowoffluidsfrom production formations into the well. There are numerous advantages to the servicing of petroleum production wells while they remain under production pressures.These advantages include the avoidance of: (a) a loss of production and timewhile circulating fluids to kill the well; (b) the costofthe kill fluids injected intothewell in ordertoterminate production; (c) the damage to theformation bythe kill fluids; and (d) thecostof putting the well back into production, especially if stimulation ofthewell is required in order to restore production flow following termination.

The performance of servicing operations on wells which are under production pressures include certain inherent disadvantages in that they involve riskto both equipment and personnel from high pressure well bore fluids and gases as well as from the explosion and combustion hazards associated therewith. Servicing ofwells under pressure requires highly accurate monitoring of pressures and precise proportional control of well servicing equipment.

This equipment may include the engines and pumps comprising a hydraulic power pack, hydraulic actuators and valves, moving and stationarytubing slips and clamps, blowout preventer rams and numerous other service equipment parameters.

When well servicing work is performed on a petroleum well under production pressures, great dangers exist from the explosiveness of well bore liquids and gases. Thus, priorartservice equipment has been controlled almost exclusively by means of hydraulic linkages between a control console andthe various valves and actuators to be controlled and the transducers to be monitored during servicing operations. This requires a large number of hydraulic flowliness or hoses to be installed and maintained for each servicing operation set up and, thus, substantial minimumchargesjustforpreparations to renderthe required well services. In addition, such hydraulicflowlines or hoses require a high degree of maintenance since hydraulic couplings and pressurized hoses are subject to frequent leaks.

Pressurized well servicing equipment includes hydraulic workover units, reeled tubing units, pumpdown service systems and wireline units, examples of which are shown in U.S.Patent Nos.

4,251,176; 4,381,904; 4,085,786; and 3,215,203. Each type of hydraulic well servicing equipment includes complex hydraulic control mechanisms which requirehighlyskilledtechnicianstooperatethe equipment and such personnel must be maintained a safe distance from hazardous conditions. In recent years safety considerations and insurance costs have become major factors in the oil well services business.

The use of hydraulic control and monitoring links in the servicing of petroleum production wells in order to achieve safety goals also includes inherent disadvantages. The lengthy monitoring and control hoses incorporate pressure drops which lead to errors in measured transducer data from the equipment and incorporate inaccuracies and imprecision in the control of the proportionally variable operating parameters and functions within the hydraulically actuated equipment. Moreover, lengthening of the hoses in order to place the operators at a greater and more secure distance from the pressurized welihead further increases these disadvantages.

One series additional disadvantage of hydraulic monitoring and control links is that because of the nature of their operation they cannot be readily adapted to multiple, alternative control stations for the same hydraulically actuated equipment. In many situations it is highly desirable to be ableto monitor and control hydraulic well servicing equipment from two or more alternative consoles. The system ofthe present invention is readily adapted to such flexible operating conditions.

Blowout preventer control and recorder systems, such as shown in U.S.Patent No. 4,337,653, are known. While such systems have suggested fiber optic linksforequipment utilized during the drilling operation they do not consider the problems inherent in equipment utilized in servicing petroleum production wells under production pressures. In particular, such drilling systems are not faced with the same degree of hazardous flammability as is encountered in the servicing of production wells under pressure nor are they concerned with proportional control of hydraulically actuated equipment. Rather they principally provide a one-shotstepfunctioncontrol ofblowoutpreventer rams used to secure a well being drilled upon the occu rrence of gas kick or simi la r emergency conditions.

The system ofthe present invention incorporates a data communications linkage such as fiber optic link to electronic control means for pressurized well servicing systems which enables the operator to be placed at any desired location considerably remote from the danger ofthe welihead area while at the same time increasing the speed, accuracy and precision of the control of servicing equipment. The fiberopticlinkcouplestheelectroniccontrol equipment of the subject system to the control consoles andthe operating equipment so as to minimize the dangers associated with the explosiveness and combustibility of highly pressurized gases and fluids inherent in the environment associated with a pressurized petroleum production well.In addition, the fiber optic link is not subject to radio or other types of electromagnetic interference which may be associated with equipment in certain petroleum production environments such as offshore platforms.

The system ofthe present invention pertains to an electronic control and monitoring system for well servicing equipment. More particularly, one aspect ofthe invention includes a control console incorporating visual indicating means for monitoring the status of various elements in the system, switches for the operation of discrete control valves, proportional control systemsforvarious operating functions, and a plurality of input registers associated with the control parameters to be effected in the welihead equipment. Also included are a plurality of output registers to be associated with parameters to be monitored atthe wellhead equipment and a control comlinkforestablishing communication between the control equipment and the wel I head.An equipmentcomlinkisassociated with the equipment located at the welihead and output registers are associated with the status of various components to be controlled at the wellhead.

Input registers convert information monitored at the welihead equipment to digital format four communication between the console and equipment comlinks.

In one aspect the invention includes, in combination with a system for servicing a pressurized petroleum production well, means for controlling the operation of various components within the servicing system and measuring the status of various parameters within the servicing system and a parameter measuring meansformonitoring various varying components within the servicing system. Operating data collection means are connected to the separate components within the well servicing system and a remote operator actuation means is connected to the components susceptible of modification within the system. An equipment comlink is connected to both the remote operators and the remote sensors associated with the well servicing system and a control console panel is located remote from the well servicing system.

In put registers for storage of indicia related to desired operating conditions within the servicing equipment are included along with a plurality of storage registers for storing data associated with actual measured parameters within the well servicing system. A control comlink is connected to both the input registers and the output registers for communication of information from the input registers and to the output registers. A communication linkisconnected between the control comlink and the equipmentcomlinkfor transferring data therebetween in order to supply information as to operating parameters to the console panel and information with respect to desired changes in the operating parameters from the console panel to the remote operators and thereby affect changes in and control the servicing equipment.

In a further aspect the system of the invention includesafullduplexfiberopticlinkconnected between the control comlink and the equipment comlinkfortransferring data therebetween.

In a still further aspect the invention is an improved system for servicing petroleum production wells of the type wherein various components within the system are monitored by sensors and controlled by actuators and which includes a control console located remotely from the sensors and actuators for providing signals to and from an operatorfor controlling the servicing system. A control terminal unit is connected to the control console for data communication therewith and an equipment terminal unit is connected to the sensors and actuatorsto reflectthe output of the sensors and effect changes in the state of the actuators.Data communication means are connected between the control terminal unit and the equipment terminal unitto displaythe outputsignalsfrom thesensors on the display console and to effect changes in the state ofthe actuators in responsetoinputsignalsfromthe console. In certain embodiments the invention may include a plurality of equipmentterminal units each being connected to a group of sensors and actuators at physically separated locations on the servicing system from one another and each being in data communications with the control terminal unit.

In another aspect the system ofthe invention includes a plurality of control consoles each one of which can receive and display information but only one of which at a time can effect direct control over the condition of the input registers of a control terminal unit.

The system ofthe invention also includes a processor for storing preprogrammed parameters with respect to the desired operational characteristics of the servicing system and controlling the input registers of a control terminal unit based upon the data stored in the output registers of a control terminal unit and preprogrammed parameters.

The additional objects and advantages ofthe subject invention can be readily apparent from the reading of the following description of a system constructed in accordance with the invention and referenced to the accompanying drawings thereof, wherein: Figure lisa side elevational view of a prior art pressurized well servicing unit illustrating problems associated therewith; Figure2 is a side elevational view of an illustrative reeled tubing pressurized well servicing unit modified in accordance with the teachings of the present invention; Figure 3 is an illustrative schematic view of a pump-down tool pressurized well servicing unit constructed in accordance with the teachings of the present invention;; Figure4 is a block diagram of a system constructed in accordance with the teachings ofthe present invention; Figure 5 is a block diagram of a comlink portion of the system of the present invention; Figure 6 is an illustrative schematic view of a snubbing unit pressurized well servicing system constructed in accordance with the teachings of the present invention; and Figure 7is a block diagram of the control system forthesnubbing unit shown in Figure 6.

Referring first to Figure 1, there is shown a side elevational view of a multicylinderhydraulic workover unit ofthe prior art. Such a system is also known as a "snubbing" unit and is used to insert and remove well tubing from a petroleum production well under pressure. In the prior art system of Figure 1,the unit is shown mounted atop the wellhead 11 of a petroleum production well having the various valves and controls associated with such a well and which are conventionally known as a Christmas Tree 12. The system includes a plurality of blowout preventers l3whicharearrangedinastackin accordance with the well conditions and the working pressure requirements of the well.Not shown in Figure 1 are the blowout preventer manifolds and the hydraulic power package including the engine, hydraulic pumps and manifold, hydraulicfluid reservoirs, heat exchangers and accumulators necessary to operate the blowout preventers and otherwell servicing equipment of the snubbing unit.

The prior art snubbing unit shown in Figure 1 additionally includes sets oftraveling slips 15 used to grip the tubing to be inserted into and/or removed from the well and which may be vertically reciprocated and rotated by hydraulic means.

Stationary slips 16 are used to grip the tubing during the snubbing and lifting operations during thetimes whenthetraveling slips are opened and being adjusted in position. An access window 17 is utilized to obtain access to the tubing being inserted and removed from the well while sealing means 18 seals the well and maintains pressure during the insertion and removal oftubingfromthewell. In addition,well tubing handling apparatus such as a hydraulic boom mechanism including a telescoping mast 21 is also arranged on the apparatus. Awork basket 22 is positioned atop the structure for use as a platform for personnel operating the unit and handling the pipe being inserted and removed from the wel I .A control console 23 includes measuring gauges and a plurality of lever actuated hydraulic control valves and is positioned within the basket 22 for use by personnel in controlling the servicing operation.

The "snubbing unit" of Figure 1 is used to both withdrawand insert lengths of well tubing from the tubing string of a well generallywhilethe well is underfull production pressure. In the inserting or "snubbing" operation, the stationary slips are closed to clamp the tubing and prevent ejection by the well pressure while the traveling slips are opened and the traveling pistons or jacks extended. The traveling slips are then closed to gripthetubing whilethe stationary slips are opened and the traveling pistons retracted to insert the tubing into the well against production pressure.When the pipe weight inserted into the well exceeds the area of the plugged tubing times the well pressure, the pipe is said to become "heavy" ratherthan "light" and the direction of forces on the hydraulic pistons orjacks must be changed accordingly. As can be seen, the constant monitoring of well pressure conditions, hydraulic power pack operating parameters, and hydraulic valve position along with the precise control of numerous proportionally variable control elements is absolutely essential for the safety of both men and equipment as well as the successful completion of the servicing task.

Prior art pressurized well servicing systems, such as the snubbing unit of Figure 1, include a mass of lengthy hydraulic control hoses 25 which lead from the work basket 22 and the control panel 23, which contains numerous hydraulic pressure gauges and the like which must be monitored by service technicians during the snubbing operation, to the numerous hydraulic control valves to perform the servicing work functions of the apparatus. The control console 23 also has a large number of hoses which must lead to and from the hydraulic power pack (not shown) from which all ofthe hydraulic operating power is drawn for the snubbing operation. Pressurized hydraulic hoses from transducers on the power pack are used to monitor conditions within the hydraulic power pack and assure that adequate uniform pressures and safe engine operating conditions are maintained during the servicing operation.

As can be seen from the priorartequipmentof Figure 1,the use of hydraulic monitoring and control lines in systems for servicing wells under pressure presents numerous disadvantages. In particular, it takes a substantial amount oftime for all ofthese hydraulic hoses to be assembled, tested and interconnected with the various components in orderto set up the initial operation. This time, as well as maintenance of leaky hoses, increases the cost of well servicing to the customer. In addition, the hydraulic hoses are subject to failure due to fatigue cycling and/or pressure surges and may be damaged by the raising or lowering of equipment in the vicinity ofthe wellhead.

There is shown in Figure 2 a unitforservicing of an operating petroleum production well under pressure comprising a reeled tubing unit which has been modified to incorporate the system of the present invention. It will be noted thatthe reel tubing unit 30 comprises truck mounted equipment which includes a truck cab 31 and bed 32 on which the equipment is mounted. The system comprises a self contained hydraulic crane 33 which suspends a chain driven injector-head 34 above the wellhead 35 and which guidesfiexibletubing 36 stored on a reel 37 and injects that tubing down into the well under pressure.

The reel motor, injector-head motor crane, power pack, BOP's and controls are all hydraulically operated. Reeled tubing 36 is fed from the reel 37 to the injector-head 34 and pushed down through the stripper42 and blowout preventers43. The chain driven injector-head 34 rapidly moves the tubing 36 into and out of the well while it remains under production pressure. Well services such as nitrogen service, natural gas or nitrogen/foam mixtures are provided down the injected tubing.

The portion ofthe mechanism shown in Figure 2 includes an elevatable operators control house or cab 38 through which the injection operation is observed and controlled by an operator.

Conventionally, a large numberof hydraulic monitoring and control hoses run between the operators console located in the cab 38 through connections in the bulkhead 39 to the various components ofthe injector-head 41 located above the well. These hydraulic control hoses are, in conventional prior art systems, directly analogous to the multiplicity of control lines shown in the prior art snubbing unit of Figure 1.As can be seen in the modified system of Figure 2 a duplex fiber optical cable is run between the control cab 38 and the injector-head 34 forming part of the servicing equipment 41 located over the well head. Moreover, the actual control panel itself can be arranged in a portable unit so that the operator need not stay in the control cab 38 but rather could walk around on the ground in the area ofthe injector head itself and achieve much more accurate observation ofthe operation and thus provide more accurate control overtheservicing operation.

It should be noted that the present invention even permits complete elimination of the operator's cab orcontrol house38. The priorart reeled tubing units require cab 38 to receive the various hoses and connect them with appropriate hydraulic valves and gauges. The present invention allows all ofthese functions to be placed in a relatively small hand-held box 40, and the operator can position himself atthe optimum location with respect to the particular operation being performed on the well. The present invention frees the operator from cab 38.

The system of Figure 2 is exemplary of the manner in which conventional units for the servicing of petroleum production wells under pressure are simplified both in time and operation by the utilization of the control equipment ofthe present invention. It should be understoodthata snubbing unit ofthe prior art Figure 1 can be similarly modified and simplified by means ofthe system of the present invention, as described below.

By way offurther example, there is shown in Figure 3 a system for servicing petroleum production wells under pressure comprising a pump down tool unit incorporating the control system ofthe present invention. The system includes a hydraulic power package 51 consisting of a diesel engine 52 mounted on a skid 53 along with a hydraulic pump 54. The engine 52 and pump 54 are connected by means of a transmission geartrain 55. The hydraulic pump drives a hydraulic flow manifold system 56 which consists of a plurality of valves which serve to deliver the required flow rate of hydraulic fluid at the desired pressure to operate the pump down system. The output of the flow control manifold is connected by means of an output hydraulic line 57to a lubricator 58.The lubricator 58 consists of a pair of adjacent elongate chambers with removable pressure tight endcaps 62 to permit well tools to be inserted into and removed from the well tubing. One lubricator chamber is located in the flow line 63 connected into a flow line leading through the Christmas Tree 64 on thewellhead 65. Awell tool is pumped from the lubricatorthrough the flow line intothetubing in the well and thereafter returned from the well tubing through the flow line intothe lubricator. Similarly, the other discharge line 66 is connected into a cylindrical chamber closed by an endcap on the other side ofthe line. The system also includes a fluid storage tank.

Thetubing strings 63 and 66are interconnected by a U-shaped crossover network to close the fluid flow path 67 down in the well. This flow passage pattern in the well tubing allows fluid circulation from the surface down the well tubing and return. Thus, by controlling pressures within the tubing well tools are pumped into and out of the well via the tubing strings. For example, well completion tools such as gas liftvalves can be installed or removed by such pumping procedures. Pumpdown techniques can be also used to render well maintenance services as paraffin cutting and the jet washing of said within the well.Pumpdown well completion and servicing procedures are especially useful in underwater or other highly deviated wells where installation and removal of tools are accomplished from remote control stations such as the system shown in Figure 3.

The system of Figure 3 includes a control console and terminal unit 71 which can be located remotely from eitherthe hydraulic power package unit 51 or thewellhead 65. The console 71 includes a display panel 72 which incorporates numerous indicator lights indicative of various conditions within the system, digital readoutdisplaysformonitoring conditions within the system, proportional control mechanisms 73 for varying and changing proportional control parameters within the system, and step function controls 74 for controlling on/off switches and valves within the system.A duplexfiber optic cable 81 interconnects the control terminal unit and console 71 with the equipmentterminal unit mounted onthe equipmentskid 51,the equipment terminal unit located at the lubricator 58 and the equipmentterminal unit located atthewellhead 65.Control signals are transmitted from the control console 71 and monitoring signals are received by the control console 71 both by means ofthe fiber optic cable 81. It should be understood that in certain embodiments of the present invention other means of data communication, such as radio frequency transmission could be used.

Referring now to Figure 4, there is shown a block diagram of a pressurized well service control system constructed in accordance with the teachings of the present invention. A console control panel 101 includes a plurality of different monitoring and control elements including indicator lights 102, control switches and proportional control inputs 103, read out displays 104 and memory means such as strip chart recorders 105. The output ofthe control panel 101 is connected to control terminal unit 100 which includes input registers 1 which store information with respect to the state ofthe servicing equipment being controlled. Input registers 110 may comprise various types of memory means including, mechanical storage, magnetic storage and otherwise.For example, control valve state information is stored in registers 111,the status of the transmission coupling between engine and pump is stored in register 112, engine start information stored at 113 and engine kill information at114. Proportional engine throttle status may be stored in register 115. The input registers 110 establish the desired status ofthe servicing equipment based upon information input by the control panel. The control terminal unit 100 also includes an array of output registers 120, comprising memory means, which store the actual measured or monitored status of information within the service equipment based upon information measured by transducers.That is, data representing actual valve positions are stored in registers 121, most recently sampled enginetach information is stored in register 122, fluid pressures at various positions within the system are stored in register 123, and fluid flow rates and quantities at various points within the system are stored in registers 124. Each ofthe units of control panel 101, input registers 110 and output registers 120 are connected to a control microprocessor 125 which stores programmed information based upon the allowable ranges and operating procedures of the system and which may be utilized to control various parameters within the system to assure that it is functioning properly.For example, it is very important to regulate the range of operating pressures within a well servicing system so that pressures are maintained above a preselected minimum value in orderto avoid dangerous situations.

A power supply 126 which may be a.c., d.c., or rechargeable batteries, provides power to the microprocessor 125, the input and output registers 110 and 120 and the control console 101 as well as a control comlink unit 130. The unit 130 includes a clock 131 which synchronizes the various components within the control side and a data encoding unit 132 which transform parallel information into serial information fortransmission to the equipmentside ofthe system. A data decoder 133 decodes data coming backfrom the service equipment sothat it can be inputtothe control elements of the system.An optical transmitter 134 and an associated fiber optical cable 136 along with an optical receiver 136 and an associated fiber optical cable 137 form afull duplexfiberoptic link between the control comlink 130 and an equipmentcomlink 140 located on a unit of the servicing equipment to be controlled. The control comlink 130 also includes a parallel to serial converter 138 for both encoding and decoding optical data on the transmission line incoming and outgoing from the control comlink 130. Finally, an array of buffer registers 139 is included for the processing of data into and out ofthe control comlink 130.

Attheotherendofthefull duplex fiber optic link 136and 137 is located an equipmentcomlink140 which similarly includes a clock 141 along with a data encoder 142 and data decoder 143. Afiber optical data receiver 144 is connected to the receive side of the fiber optic cable link 136 while a fiber optic data transmitter 145 is connected to the transmit side 137.

An array of parallel to serial converters 146 is connected to translate data into and out ofthe system while a array of buffers 147 is included for the temporary storage of data to facilitate its movement intoandoutoftheequipmentcomlink140.Apower supply 148 connects power to the equipment comlink 140. The outputofthe equipmentcomlink is connected to an output control system 150 which comprises a clock 151 and an array of latches 152 for affecting the gating of control information from the equipmentcomlink 140 to an equipmentterminal unit 200 which includes an array of remote operators 160 mounted on the service equipment and used to make adjustments in the operation of the system.

The remote operators 160 of the equipment terminal unit 200 may include a plurality of valves 161 which control hydraulic fluid flow within the system as well as a quantitive throttle adjustment operator 162, a transmission shift operator 163, an engine/start actuator 164 and an engine/kill actuator 165. For added flexibility a local control module 170 allows direct control over the engine/pump system which includesvalvecontrol 171, engine/throttle control 172,engine/startcontrol 173 and engine/kill control 174.

The equipment terminal 200 also includes a plurality of remote sensors 180 by means of which numerous parameters within the operating well servicing system are monitored. These sensors may include an enginetachometerl8l,well pressure sensors 182, valve position sensors 183, and fluid flow monitor sensors 184. In addition, engine parameter transducers such as engine oil pressure sensor 185 and an engine water temperature sensor 186 are monitored. Transmission oil pressure is monitored by sensor 187 and transmission oil temperature are monitored by sensor 188. Pump oil pressure and temperature are monitored at 189 while hydraulicand pneumaticpressureswithinthe system are monitored by sensors 191 and transmission position indicators monitoring the transmission coupling between the pump and engine at 192. The output of each of the remote sensors 180 ofthe equipmentterminal unit 200 are connectedto an analog to digital converter array 190 the output of which are connected into the equipmentcomlink140andservetosupplydigital information relative to each of the remotely sensed conditions in the system to the equipment comlink 140 for the supplying of data back to the control terminal unit 100through the control comlink 130. In practice, the equipment comlink 140 may physically include the output control system 150 and the A/D converters 190 as a composite unit or they may be incl uded as part of the equipment terminal unit200.

The system includes data handling and transmission elements which vastly improve the quality and speed of control overwell servicing in contrast to the prior art hydraulic monitoring and control systems. In addition, the full duplexfiberoptic link 136/137 allows one or more control consolesto be located at any position with respect to the wet ahead and thus maximize the safety of personnel required to control the operation while at the same time minimizingthe danger of explosion dueto electrical discharge upon severance ofthe cable.

Moreover, the system is adapted so that in the event there is a severing ofthefiber optic link 136/137 between the control comlink 130 andthe equipment comlink 140 the system supply enters into a safety shut down mode until the linkage has been repaired.

Referring now to Figure 5, there is shown a block diagram of an embodimentofcomlinkcircuitry usable in the system of the present invention. An opticaltransmitter201 maycomprisea semiconductor laser which is modulatable at high frequency sufficient to pulse code modulate data onto a fiber optical cable. Similarly, an optical receiver 202 consists of photodiode circuitryfor receiving pulse code modulated optical information from a fiber optic link. Both the transmitter 201 and receiver 202 are connected to a manchester encoder/decoder 203 which serves to provide synchronization pulses into a serial stream of data in orderto efficiently encode/decode data to and from thefiberoptical link.Thecomlinkshown in Figure5 maybe either a control comlinkcircuit 130 oran equipmentcomlinkcircuit 140 depending upon which direction data is flowing through the system.

Forexample,parallel data inputintothe parallel/serial convertors 204 and 205 may be either monitored data from the equipment or input data from the control panel on the control console.

Parallel data entering through convertor 204 and 205 are routed through a counter 206 under control of a system clock 207 the signal from which is divided by a one second/one minute counter 208 actuating through a monostable multivibrator 209. Another monostable multivibrator 211 gates signals into the encoder/decoder 203. The counter 206 serves to divide the data into discrete data words for identification by the encoder 203. Similarly, the manchester encoder/decoder 203 gates clocksignals through a monostable multivibrator 212, a counter 213and a monostable multivibrator214to control the data outputflowon leads 01-Q8 through a pairof serial/parallel convertors 215 and 216.A pair of AND gates 217 and 218 serveto timethe gating of information into the convertors 215 and 216. An AND gate 210 actuated under control ofthe encoder/decoder 203 regulates the flow of information into the system by means of the parallel to serial convertors 204 and 205.

Referring now to Figure 5, there is shown a illustrative schematicview of a multicylinder hydraulic snubbing unitforpressurizedwell servicing constructed in accordance with the present invention. The system comprises a multicylinder hydraulic workover unit mounted atop a welihead 311 of a petroleum production well having various conventional valves and controls 312 associated therewith. The system includes a plurality of blowout preventers 313 arranged in a stack in accordance with the working pressure requirements of the well.

The snubbing unit also includes sets of traveling slips 315 used to grip the tubing to be inserted and/or removed from the well and which are vertically reciprocated and rotated by hydraulic actuation means. Stationary slips 316 are used to grip the tubing during the snubbing and lifting operation. A window 317 is utilized to provide access to the tubing being inserted and removed from the well while a sealing means 318 maintains the pressure of the well during the insertion and removal oftubing from the well. Well tubing handling apparatus such as a hydraulic boom mechanism having a telescoping mast321 are also included as partofthe hydraulic workover apparatus.

Aworkbasket322 as positioned atopthesnubbing unit structure for use as a platform to housethe technicians operating the unit and handling the pipe inserted and removed from the well. A primary control console 323 has associated therewith a control terminal unit324whichcontainsvarious input and output registers as well as other control equipment and an equipment terminal unit 327 which includes remote operators and sensorsforthe equipment in the work-basket area. The primary control console 323 mounts a plurality of different monitoring and control elements including indicator lights, control switches, proportional control inputs, readout displays and various memory means.Within the control terminal unit324are contained various input and output registers which are in communication with the primary control console and a control comlink326which serves to provide a data communications link between the primary control console 323 and the other elements ofthe system. The work-basket equipment terminal unit 327 and the control terminal unit324 are each associated, respectively, with a equipment comlink 328 and a control comlink326.

An auxillary control console 330 includes an auxiliary control console comlink331 and is positioned at a location remotefrom (or movable with respect to) the workbasket primary control console 323. A power pack 340 is also located remote from both the snubbing unit structure and the auxiliary control console 330. The power pack 340 is connected to the outer units by means of an equipmentterminal unit 338, an equipmentcomlink 339 and a coupling cable 340. Cable 340 includes a duplexfiberoptic link342 and a composite cable343 which also contains a fiber optic link, a high pressure hydraulic line, a hydraulic return line and a power cable for applications where electrical power is required for trickle charge of equipment actuator batteries. The composite cable 343 connects each of the power pack equipment terminal unit 338 and comlink 339; the blowout preventer stack equipment terminal unit344andequipmentcomlink345;the jack equipment terminal unit 341 and comlink342; andtheworkbasketterminal unitandcomlink324to each otherandtothe primary and auxillarycontrol console comlinks 328 and 331. The auxillary control console 330 and the primary control console 323 comlinks 331 and 328 are coupled by a fiber optic link 346.

Thus, in accordance with the teachings of the system in the present invention, the various hydraulic actuators can be controlled by either ofthe two control consoles, the primary control console 323 orthe auxiliary control console 330, and they can communicate with each other.

Similarly, each of the various operation parameters, including conditions of valves, status of pressures, engine rpm, etc. can be monitored by means of either the primary control console 323 or the auxilIary control console 330. The two consoles 323 and 330 are linked to one anotherthrough console priority selector units which determine which one of a plurality of separate interconnected consoles would be capable of controlling the state of the various control equipment parameters. The control console priority selectors are located in each of the control console terminal units. Thus, an operator is certain as to which one of the consoles is in charge of and hastheresponsibilityforactuation and operation ofthe various parameters and controls within the system. All consoles may monitor all of the various parameters all ofthetime.

Referring to Figure 7, there is shown a block diagram ofthesnubbing unit of Figure 6. In particular, there it is shown that the primary control console 323 is located in the workbasket area and associated with a control terminal unit 324 and a control comlink326. Also located in theworkbasket area are certain remote sensors and operators which are associated with a workbasket equipment terminal unit 327 and an equipmentcomlink328.

Similarly, the jack equipment terminal unit 341 and equipment comlink 342 are associated with the remote sensors and operators controlling the jack equipment. The blowout preventer stack equipment terminal unit344 and equipment comlinks 345 are associated with remote operators and remote sensors responsible for monitoring and control of the blowout preventer stack 312.The power pack equipment terminal unit 338 and equipment comlink 339 are connected with the remote sensors and operators associated with monitoring and control of the hydraulic powerpack unit340. The auxillary control console 330 is associated with a control terminal unit 351 and a control comlink331 which is coupled to the control comlinks 326 ofthe primary control console323 by means of the fiber optic link 346. The primary control console 323 is associated with a microprocessor 352 while the auxillary control console 330 is associated with a microprocessor 358.

The microprocessors 352 and 358 enable storage of programmed information based upon the allowable ranges and operating procedures of the well servicing system and may be used to control various parameters within the system to ensure that it is functioning properly. Each of the control consoles 323 and 330 are associated with a control priority selector354which ensures that both consoles monitortheremotesensorsallthetimebutonly allow one console at a time to control the remote actuators. An operator initiated command is required to change the control function from one console to the other.

In Figures 6 and 7 it is shown thatthe primary control console 323 is located in the workbasket of the snubbing unit. The control terminal unit324is associated with the console 323 along with a primary control comlink 326. Because the workbasket location also includes equipment functions as well as control functions it also has an equipment terminal unit327 and an equipmentcomlink328.

The primarycontrol console323 is used bythe operating technician to both monitor and control various system parameters. As a monitor the control console 323 may include numerous indicator lamps and visual displays to indicate to the operator the statusorvalueofthefollowingsystem parameters: stationary slips status; stationary slip selection (upper/lower); travelling slips status, traveling slips position (jack position); pipe position; weight and light/heavy status; pipe travel direction; cylinder pressure; running/pulling speed; hydraulic pressure, temperature, flow rate and oil level; stripping preventers status; safety preventers status; pipe ram status;BOP accumulator pressure; kill valve status; wellhead and annulus pressure; engine rpm, oil pressure and oil temperature; and pump piston status (loaded/unloaded).

The console 323 may be used as a control panel to effect both on/offaswell as proportional control over the following system parameters: stationary slips selection; stationary slips open/close; traveling slips open/close; jack position and cylinder pressure; BOP control (open/closed); pump on/off; engine on/off and speed; and kill valve open/closed.

As explained in connection with the pumpdown unit embodiment of the present invention shown in Figure 4, primary control console 323 is connected to the control terminal unit 324which includes input registers for storing information with respect to the desired state ofthe parameters being controlled and output registers which store the actual measured or monitored status of parameters within the servicing equipment as measured by sensors. The primary control terminal unit324 is coupled to the control comlink 326 which is in data communication with the other control and equipment comlinks ofthe system.

The workbasket equipment terminal unit 327 includes remote sensors for monitoring equipment parameters and remote operators for effecting control over equipment of that area. Forexample,theequip- ment terminal unit 327 enabies both monitoring and control ofthe traveling slips status and position as well as pipe position. The workbasket equipmentter- minal unit 327 is connected to the workbasket equip ment com I ink 328 to com municate with both the primary control console comlink 326 and the auxil Iary control console comlink331.

Both the primary control console 323 and the auxillary control console 330 include a control priority selector 354 which are prioritized so that only one console can command the servicing equipment at a time. Both consoles may monitor all parameters all the time but an operator initiated act is required to change the command function from oneconsoleto the other. Each console may also include a microprocessor 352 and 358 for preprogrammed control and response.

Thejackequipmentterminal unit341 also includes remote sensors for monitoring equipment parameters and remote operations for effecting control over equipment ofthe jack area. For example, the jack equipmentterminal unit 341 enables monitoring ofthe upper and lower cylinder parameters (and, thus, pipe weight) as well as running/pulling speed of the pipe and control overthe stationary slips forthe pipe handling. The equipment terminal unit 341 is connectedtothe primary and auxillarycontrol consoie comlinks326 and 331 by means ofthejackequi- pment comlink 342.

The blowout preventer stack equipment terminal unit 343 includes remote sensors for monitoring equipment parameters and remote operators for effecting control over equipment in the BOP stack. The accumulator pressure, welihead pressure and annulus pressure are monitored while the conditions of the BOP's open/closed selections and kill valve are both monitored and controlled by the equilpment terminal unit344. Communication between both the primary control consolecomlink326andtheauxil- larycontrol console comlinks 331 andthe BOP stack equipment terminal unit 344 is maintained bythe BOP equipmentcomlink345.

The engine, pumps, hydraulic reservoir and other auxiliary equipment comprising the power pack 340 are coupled to a power pack equipmentterminal unit 338. This unit includes remote sensors for monitoring engine rpm, engine oil pressure,andtem- perature, as well as hydraulicfluid pressure, tem- perature and level. Engine rpm, and hydraulicfluid pump parameters are controlled by remote actuators in the equipment terminal unit 338. Communication between the power pack equipment terminal unit 338 and the control comlinks 326 and 331 is maintained bythe power pack equipment comlink339.

Eachoftheequipmentterminal units and the associatedequipmentcomlinkswill include an output control system for the remote operators and analog/digital converters forthe remote sensors to facilitatedata handling through the equipmentcomlinks.

As can be seen, the snubbing unit embodiment of the system ofthe present invention is effectuated in thesamemannerasthepumpdowntool embodiment of the system and allows the safe accurate effectuation ofcontrol over a pressurized well servicing unit in accordance with teachings ofthe present invention.

Thus, in operation it can be seen that the system of the present invention includes means for monitoring various parameters within the pressurized well servicing unitwhich includes the respective positions of various cylinders, valves, slips throttle adjustments and transmission linkages within the system as well as the value of data such as engine tachometer readings, well and cylinder pressures and numerous other parameters intergral to the proper operation of the pressurized well servicing system. These data are encodedandsentfromequipmentterminal unitsvia equipmentcomlinks over data communication lines to control comlinks and a control terminal unit wherein the information is stored in registers and provided to both a control panel and a control microprocessor.Similarly, changes may be made in the operation of the servicing system equipment by means of either manual input via the control panel or by microprocessor control so that desired parameter values may be stored in registers in the control terminal unit and fed via a control comlink, a data transmission path, and an equipment comlinkto a selected equipment terminal unit. These signals then cause the remote operators to change the position or condition of valves and cylinders and make proportional adjustments in the various parameter and function controls as well as the various proportional hydraulic system controls associated with the well servicing system.

Itshould be understood thatwhile Figures3-7 are based upon the specific examples of well servicing units the system of the present invention is equally applicable to other forms of pressurized well servicing systems. The reeled tubing, pumpdown tool and snubbing unit systems are merely given as an ex emplaryembodimentsofthe monitoring and control system of the present invention for well servicing systems.

Is should be understood thatthe present invention is well adapted to carry outthe objects and attain the ends and advantages specifically mentioned as well as other inherent in the disclosure. While the presently preferred embodiment ofthe invention is given for the purposes of illustration and disclosure, numerous changes in the details of construction, application and arrangement of parts and components may be madeandwhich will readilysuggestthemto those skilled in the art and which are encompassed within the spirit and scope of the invention and within the scope of the appended claims.

Claims (24)

1. An improved system for servicing petroleum production wells ofthe type wherein various components within the servicing system are monitored by sensors and controlled by actuators, said improvement comprising: input registers for storing indicia related to desired operating conditions within said system; output registers for storing data from said sensors; a control comlinkwithin said system connected to said input registers and said output registers and providing communication therebetween; an equipment comlinkwithin said system connected to said sensors and said actuators; and a fiber optic cable link coupling said control and equipment comlinks for transferring data therebetween to facilitate the remote operation of said actuators in accordance with indicia stored in said input register.

2. Thesystem assetforth in claim 1 andfurther including a control console panel located remotely from said component actuators and connected to said input registers and to said output registers.

3. The system as set forth in claim 2 wherein said control panel comprises indicator means for displaying datafrom said output registers and meansforentering data into said input registers.

4. The system as set forth in claim 3 wherein said control comlink is disposed within said control con sole and furthercomprises meansforencoding and decoding data transferred through said fiber optic cable connected to said equipmentcomlink.

5. The system as set forth in claim 4wherein said equipment comlink includes meansforencoding and decoding data transferred through said fiber optic cable link.

6. The system as setforth in claim 1 wherein said fiber optic cable comprises a full duplex fiber optic cable link.

7. The system as set forth in claim 1 wherein said system for servicing petroleum production wells is a type selected from the group consisting of a pumdown tool unit, a reeled tubing unit, a hydraulic workover unit and a wireline unit.

8. The system as set forth in claim 1 a control microprocessor connected to both said input registers and said output registers for varying the indicia stored in said input registers response to information contained within said output registers.

9. The combination with a system for servicing a pressurized petroleum production well including means for controlling the operation of various components within the servicing system and measuring the status of various parameters within the well servicing systems, comprising; measuring sensor means for monitoring varying parameters within components of the well servicing system; remote operator actuation means connected to various components susceptible of modification within the well servicing system; an equipment comlink connected to both the remote operator actuator means and the remote sensor means associated with the well servicing system; a plurality of input registersforstoring data associated with measured parameters within the well servicing system components;; a control console panel located remote from the well servicing system and connected to display data stored in said output registers and inputindicia into said input registers; a control comlink connected both the input regis-ters and the output registers for communication of information to said output registers and from said input registers; and a communication link between said control comlink and said equipmentcomlinkfortransferring data therebetween to supply information with respect to measured operating parameters to the control console panel and information with respectto desired changes in the operating parameterfromthecontrol console panel to the remote operators and affectthe changes therein remotelyfrom the equipment.

10. Thesystem assetforth inclaim9wherein said communication linkcomprises; a full duplexfiber optic cable link connected be- tween the control comlinkandtheequipmentcom- linkfortransferring data therebetween.

11. Asystem of claim 9which also includes a pro cessorfor storing preprogrammed parameters relative to the well servicing system and controlling the input registers in response to said preprogrammed parameters and information stored in said output registers.

12. Asystem as set forth in claim 9 wherein the system for servicing petroleum production wells is a type selected from the group consisting of a pumpdown tool unit, a reeled tubing unit, a hydraulic workover unit and a wireline unit.

13. An improved method for servicing petroleum production wells of the type wherein various components within the servicing system are monitored by sensors and remotely controlled by actuators, said improvement comprising steps of: providing input registers for storing indicia related to desired operating conditions within said systems; providing output registers for storing data from said sensor; connecting said input registers and said output re gistersfor providing communication therebetween relative to desired operating conditions and monitored data from said sensors; providing an equipment comlinkwithin said system; connecting said sensors and said actuatorstosaid equipment comlinkfor providing communication therebetween;; providingafiberopticcablelinkconnectingsaid equipment comlink with said input and output registers; transferring data along said fiber optic cable link between said equipment comlink and said input and output registers; and remotely operating said actuators in accordance with indicia stored in said input register along said fiber optic cable link.

14. An improved method for servicing petroleum production wells as set forth in claim 13,wherein step of connecting said input registers and said output registers includes providing a control comlink.

15. An improved method for servicing petroleum production wells as set forth in claim 13, wherein said step of connecting said input register and said output registers includes providing a control console for displaying the contents of the output register and changing the contents of the output registers.

16. An improved system for servicing petroleum production wells ofthe type wherein various components within the system are monitored by sensors and controlled by actuators, said improvementcomprising; a control console located remotely from said sensors and actuators for providing signals to and from an operator for controlling said servicing system; a control terminal unitconnectedto said control console for data communication therewith; an equipmentterminal unitconnectedto said sensors and actuators to reflect the output of said sensors and effect changes in the state of said actuators; ; meansfordatacommunication between said con trolterminal unitandsaidequipmentterminal unitto display the output signals from said sensors on said display console and to effect changes in the state of said actuators in response to inputsignalsfrom said console.

17. An improved system for servicing petroleum production wells of the type wherein various components within the system are monitored by sensors and controlled by actuators as set forth in claim 16, wherein said data communication means comprises: a control comlinkin data communications with said control terminal unit; an equipment comlink in data communications with said equipmentterminal unit; and means for data communications between said control and equipment comlink.

18. An improved system for servicing petroleum production wells of the type wherein various components within the system are monitored by sensors and controlled by actuators assetforth in claim 17 wherein: said data communications means includes a fiber optic link.

19. An improved system for servicing petroleum production wells ofthe type wherein various components within the system are monitored by sensors and controlled by actuators as set forth in claim 16 which also includes: an auxiliary control console located remotelyfrom said control console; and means for data communications between said auxillary control console and said equipmentterminal unit to reflect the output of said sensors and effect changes in the state of said actuators

20. An improved system for servicing petroleum production wells ofthe type wherein various components within the system are monitored by sensors and controlled by actuators as setforth in claim 19 wherein said data communications means includes a control terminal connected to said auxillary control console for data communications therebetween.

21. An improved system for servicing petroleum production wells of the type wherein various components within the system are monitored by sensors and controlled by actuators as set forth in claim 19 wherein said control console and said auxillary con- trol console are in data communications with each otherandwherein each includes: control priority selector means for allowing each console to monitor said sensors but only one console to effect changes in the state of said actuators and requiring an operator initiated signal to change the command function from one console to the other.

22. An improved system for servicing petroleum production wells ofthe type wherein various componentswithin the system are monitored by sensors and controlled by actuators as set forth in claim 16 which includes: a plurality of equipment terminal units each being connected to a group of sensors and actuators at physically separated locations on the servicing system from one another and each being in data communications with said control terminal unit.

23. An improved system for servicing petroleum production wells of the type wherein various components within the system are monitored by sensors and controlled by actuators as set forth in claim 22 which also includes: an equipment comlinks connected to each of said plurality of equipmentterminal units; a control comlinks connected to said control terminal unit and means for data communication between said control comlink and each of said plurality of equipment comlinks.

24. An improved system for servicing petroleum production wells of the type wherein various components within the system are monitored by sensors and controlled by actuators as set forth in claim 23 wherein: said data communications means comprises a fiber optic link.