WO2019068166A1

WO2019068166A1 - Advanced inflow control system

Info

Publication number: WO2019068166A1
Application number: PCT/CA2018/000184
Authority: WO
Inventors: Ronald Van Petegem
Original assignee: Packers Plus Energy Services Inc
Current assignee: Packers Plus Energy Services Inc
Priority date: 2017-10-04
Filing date: 2018-10-04
Publication date: 2019-04-11
Anticipated expiration: 2020-04-04

Abstract

A magnetic inflow control system (MAG-ICD) for controlling fluid inflow is provided which is based on a variation of conductivity and dielectric constant of fluids as an indicator of a well condition. The MAG-ICD is adapted to vary the flow rate of the fluid flowing in the production string when a water breakthrough is detected in the flow path. This way, if the reservoir recovers and the water content is reduced, the MAG-ICD can recover and allow for flow through the MAG-ICD to increase. If water break through should re-occur, the MAG-ICD will again respond to the increase in water production and choke flow through the MAG-ICD. The MAG-ICD is also adapted to incrementally reduce the flow in a production zone of a well upon detection of water or gas, as opposed to oil.

Description

Advanced Inflow Control System

Related Patent Applications

[001] This application takes priority from a US provisional application

62/567,781 filed on October 4, 2017.

Technical field

[002] This specification relates to a flow control system for a wellbore, and in particular to an advanced flow system including both autonomous and surface controlled such systems for control of the flow of fluids into a wellbore.

Background

[003] Wellbore production involves installing a production string, made of a plurality of production devices, inside a wellbore to allow the oil/ gas to flow from the reservoir/ formation to the surface through the production devices of the production string. Generally, when a producing wellbore formation is flowing, oil, gas or water either as a single phase or any combination of phases, the flow can occur in unpredictable or suboptimal manners. For example, a pressure or a rate of fluid flowing into the production string or a permeability at one part of the well could be significantly higher than the rate at another part of the well.

[004] Also, the oil-water ratios may change as a result of the changes in the bottom hole conditions such as differences between the average reservoir pressure and the flowing bottom hole pressure during production, in a phenomenon known as "coning". Coning is a production problem in which gas or bottom water infiltrates the perforation zone in the near-wellbore area and reduces oil production. Coning only develops once the pressure forces drawing fluids toward the wellbore overcome the natural buoyancy forces that segregate gas and water from oil.

Coning can occur in horizontal wells near the heel, and in vertical or slightly

l deviated wells, and is affected by the characteristics of the fluids involved and the ratio of horizontal to vertical permeability. Coning can cause many issues such as reduction of hydrocarbon flow, excessive water flow, excessive gas flow or excessive annular flow. Additionally, over time, the relative quantity of each phase (water, gas, crude oil) may change and one or more phases may dominate the flow.

[005] Besides the above described inflow rate variations between the heel and the toe of a well, other inflow variations amongst other well bore sections may exist and may also require inflow regulation. Furthermore, many wellbores may intersect several reservoirs, and each reservoir may have different hydrocarbons, porosity, permeability and pressure regimes. As a result, one reservoir may deplete faster than the other, causing early onset of water or gas breakthrough. Thus, one zone or reservoir within the same wellbore may impede the production of other zones or reservoirs.

[006] Moreover, production of multiple phases, such as water/gas production can cause many problems, such as productivity loss, equipment damage, and/or increased treating, handling and disposal costs at the surface. These problems are further compounded for wells that have a number of different completion intervals and where the formation pressure may vary from interval to interval. As such, water or gas breakthrough in any one of the intervals may threaten the remaining reserves within the well.

[007] Therefore, in order to regulate the flow between the formation and the production tubulars, Inflow Control Devices (ICDs) are generally employed that may also be used to reduce coning and other inflow and/or outflow effects such as, but not limited to gas or water breakthrough. ICDs devices beneficially balance the inflow profile of crude along one or more producing formations and help prevent gas/water breakthrough.

[008] Prior art ICDs can be of a choke-type, which use chokes, and/or a nozzle, and are based on Bernoulli's principle. Generally, conventional choke-type ICDs employ a nozzle to create a drop-in pressure, which can be used to regulate the flow. Other prior art ICD types, called tortuous and helical flow path ICDs, employ a flow path formed by constraining walls in which the flow path has numerous corners along the flow axis, which cause numerous directional changes in the fluid passing therethrough, and which can therefore also regulate the flow. Both helical and tortuous flow paths are typically governed by the Darcy-Weisbach equation and can thus be sensitive to changes in fluid viscosity.

[001] Still further, fluidic or fluid amplification devices are known. These devices typically take one fluid stream and jet it into another, normally at an angle, causing a change in amplification or velocity or even flow direction.

[009] The flow paths in conventional ICDs are typically fixed and contain no moving parts. However, conventional ICD's available do not typically autonomously reduce water flow within low (e.g. <10 cP) viscosity crude.

[0010] Although the multi-zone completion systems provide reservoir

management functions through controlled opening/closing of each zone, it would be highly beneficial to address common reservoir management challenges such as inter-zonal flow commonly known as cross-flow, water/gas breakthrough, production allocation, opening/closing zones, etc., without intervention.

[0011] Recently a new type of ICD called an autonomous ICD (A-ICD), or an autonomous flow control system (A-FCS), was developed to address the above- mentioned problems of conventional ICDs. A-ICDs are designed to autonomously detect the type of fluid based on a fluid property, and in response to such detections, significantly restrict or clear the path of the flow. This way, if the reservoir recovers and the water portion of the flow is reduced for example, the A- ICD/A-FCS can automatically recover and allow for flow to decrease or increase autonomously as needed.

[0012] An autonomous ICD (A-ICD) that changes state based on the density of a fluid is described in the Applicant's patent application US20170044868 (van Petegem et al.) entitled "Inflow Control Device For Wellbore Operations", having a priority date of August 13, 2015, which is incorporated herein by reference.

[0013] It is known that indicators of well conditions other than the density of the fluids could work well in a variety of well scenarios. The conductivity and dielectric properties of formation water versus those of crude are significantly different. In fact, for many years, the oil industry has been using these unique properties to determine various reservoir fluid characteristics for logs.

[0014] Electromagnetic flow meters (commonly referred to as magmeters), which are widely used across different industries, operate based on Faraday's principle that an electrical conductor moving through a magnetic field produces an electric signal within the conductor. In the case of magmeters, fluid such as oil or water act as the conductor, and electromagnetic coils surrounding a flow tube in the magmeter generate the magnetic field. To accurately measure flow, these devices require conductive fluids. In principle, a magmeter has two electrodes embedded on opposite sides of the flow tube to sense the signal. The voltage detected at the electrodes is directly proportional to the flow velocity, the intensity of the magnetic field, and the distance between electrodes. As shown in Figure 1 , a magmeter 100 uses permanent magnets 12' and 12". The fluid flow is shown with the arrow 10, and the electrodes (only one is visible) are denoted by reference numeral 14.

[0015] A disadvantage with magmeters is that they require a conductive fluid. Depending on temperature and the various properties of the crude and formation water however, the conductivity of crude is very low (in the range of 30 to 60 times smaller than the conductivity of water). This makes magmeters unsuitable for flow measurement of crude. In addition, traditionally, it has been difficult to deliver power to such EM devices when they are located downhole in active sections of a wellbore. Summary

[0016] It is an object of this specification to provide an advanced inflow control system for controlling production fluid parameters in a flow path established between a production string and a formation.

[0017] It is an object of this specification to provide a magnetic autonomous inflow control system (MAG-ICD) based on a variation of conductivity and dielectric constant of fluids as an indicator of a well condition. The MAG-ICD is adapted to autonomously vary the flow rate of the fluid flowing in the production string when a water breakthrough is detected in the flow path. This way, if the reservoir recovers and the water content is reduced, the MAG-ICD can recover and allow for flow through the MAG-ICD to increase. If water break-through should occur, the MAG- ICD will again respond to the increase in water production and choke flow through the MAG-ICD. The MAG-ICD is also adapted to incrementally reduce the flow in a production zone of a well upon detection of water or gas, as opposed to just oil.

[0018] Still another object of the invention embodiments described herein is to provide an advanced modular inflow control system that enables increased completion flexibility and zone count, by addressing reservoir management challenges such as cross-flow, water/gas breakthrough, production allocation, opening/closing zones, etc., without intervention. It is another object of the invention to provide reliable power for such flow control operations without necessarily having to do so by using power sources at the surface or by using well intervention operations.

[0019] To meet these objectives, a MAG-ICD for controlling liquid flow in a flow path established between a base pipe and a subterranean formation, is described herein comprising: a signal generator, having a tubular body adapted to be placed on the base pipe around the flow path, adapted to produce an electrical signal upon detecting presence of a water component in the flow path based on conductivity of water; and a flow controller adapted to restrict the flow path in response to the electrical signal. The system described herein also provides a method of advanced flow control for controlling liquid flow in a flow path established between a base pipe and a subterranean formation, comprising: generating an electrical signal upon detecting presence of a water component in the flow path based on conductivity of water; and restricting the flow path in response to the electrical signal.

[0020] Advantageously, the MAG-ICD described here may provide a minimal debris sensitivity, is dormant unless water is detected in the fluid flow and presents high sensitivity to increased water content. As the water detection system disclosed herein does not require any pressure drops to operate (i.e., for power), it may be used for many other types of water control applications, including but not limited to thru-tubing water control systems. No outside power source is needed for one of the basic embodiments, as the systems power requirements are low enough to be satisfied using a piezoelectric based or oscillating electric downhole power harvesting module.

[0021] Another advantage of the embodiments of the MAG-ICD described herein is that it can be designed with analog electronics, allowing for much higher temperature ratings (>325°F) and reduced cost. Still further, the actuators used by the system can be made with highly erosion resistant materials such as ceramics thus being erosion/corrosion resistant, while allowing for very small (i.e., nanometer scale) incremental movements (linear, rotational, multi-axes). This results in a large range of control of the fluid flow composition.

Brief Description of Drawings

[0022] The drawings accompanying and forming part of this specification are included to depict certain aspects of the invention. A clearer impression of the invention, and of the components and operation of systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings, wherein identical reference numerals designate the same components. Note that the features illustrated in the drawings are not necessarily drawn to scale.

[0023] Figure 1 illustrates the prior art electromagnetic flow meter.

[0024] Figure 2a illustrates the MAG-ICD when the flow is not obstructed.

[0025] Figure 2b illustrates the MAG-ICD when the flow is obstructed.

[0026] Figure 2c is a three-dimensional view of the MAG-ICD embodiment of Figures 2a and 2b.

[0027] Figure 3a illustrates the MAG-ICD when the flow is not obstructed.

[0028] Figure 3b illustrates the MAG-ICD when the flow is obstructed.

[0029] Figure 3c shows an embodiment of a fluid oscillator that uses two fluid jets.

[0030] Figure 4a illustrates a valve of the MAG-ICD obstructing the fluid flow.

[0031] Figure 4b illustrates the valve of the MAG-ICD leaving the flow unobstructed.

[0032] Figure 4c is a three-dimensional view of the MAG-ICD embodiment of Figures 4a and 4b.

[0033] Figure 5a illustrates a valve of the MAG-ICD in the closed position obstructing the flow to the fluid port

[0034] Figure 5b illustrates the valve of the MAG-ICD in the open position allowing the flow to the fluid port.

[0035] Figure 5c is a three-dimensional view of the MAG-ICD disc valve illustrated as part of the MAG-ICD embodiment of Figures 5a and 5b.

[0036] Figure 6 is an exterior view of a modular embodiment of the MAG-ICD

Detailed Description

[0037] Various features and advantageous details of the proposed devices, systems and methods are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known starting materials, processing techniques, components and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating some embodiments of the invention, are given by way of illustration only and not by way of limitation. Various substitutions, modifications, additions and/or rearrangements within the spirit and/or scope of the underlying inventive concept will become apparent to those skilled in the art from this disclosure.

[0038] As discussed above, embodiments described herein provide autonomous inflow control systems, including modular inflow control devices, for controlling flow of fluid between the formation and wellbore, e.g. the flow rate, pressure drop, or both of a fluid or a composition of fluids.

[0039] Figures 2a and 2b illustrate examples of an electro-magnetic autonomous flow control system 200, also referenced herein as a MAG-ICD. Figure 2c shows an isometric view of the embodiment of the autonomous flow control system 200 of Figures 2a and 2b. The autonomous flow control system 200 includes a device casing 202 that houses various components of the autonomous flow control system 200. The device casing 202 includes an inlet 204 to allow ingress of the fluid into the autonomous flow control system 200, a flow path 206 to allow the fluid to pass through the system 200, and a port 208 to allow the fluid to egress the autonomous flow control system 200 and flow into an interior of a sub on which the autonomous flow control system 200 is mounted. Further, the autonomous flow control system 200 includes a signal generator 210, comprising magnets 212 and electrodes 214 placed at opposite sides of the flow path 206 inside the device casing 202, to provide an electrical signal to control the flow based on the electrical conductivity of the fluid flowing through the flow path 206. As mentioned above, the electric signal is generated based on the electrical conductivity of the fluid. For example, when crude flows through the autonomous flow control system 200, no signal will be generated due to oil's relatively lower electrical conductivity. However, an electrical signal is generated when water flows through the autonomous flow control system 200, due to water's relatively higher electrical conductivity.

[0040] The autonomous flow control system 200 also includes a flow controller 216 placed downstream with respect to the signal generator 210. The flow controller 216 is adapted to restrict the flow path 206 at various levels of blockage based on an amount of the water component detected in the flow path 206 The flow controller 216 comprises a flow regulator 218 that controls the opening and closing of the port 208, and an actuator 220 that actuates the flow controller 216 based on the electric signals received from the signal generator 210. In one example, the flow regulator 218 can swing across a breadth of the flow path 206 to obstruct the flow of the fluid flowing towards the port 208. During operation, the electrical signals generated by the electrodes 214 in response to a change in electrical conductivity are sent to the flow controller 216. Further, the autonomous flow control system 200 remains in an 'dormant' state in which the flow is not obstructed, until water flows through it and attains an 'active state' in which the flow is obstructed.

[0041] In one embodiment, the actuator 220 can be piezo-electric and made of a magnetic shape memory alloy (MSMA). Other actuator options such as bimetal may also be used. It is to be noted that the actuator 220 does not have to have the shape shown in Figures 2a and 2b, and that other variations are possible.

Regulator 218 can include but are not limited to: a flapper style (shown), or a gate valve or even rotational mechanisms, illustrated later herein. Examples of regulators are provided in Applicant's co-pending patent application publication number US20170044868 (van Petegem et al.), which is incorporated herein by reference.

[0042] In a preferred embodiment, high-power permanent magnets are used to create a magnetic field that can interact with fluid flows to generate piezo-electric powered electric fields. In this embodiment, the permanent magnets can be rare Earth Magnets and are typically made from Neodymium, AInico (ALNiCo) or SmCo. Neodymium is one of the strongest permanent magnet on the market today and available for operating temperatures of up to ~392°F, and it has high resistance to both erosion and corrosion. The Alnico magnets are not as strong but can be used in temperatures over 1000°F, SmCo magnets are also well suited for high temperature applications but at about 60% the strength of Neodymium.

[0043] The actuator 220 could be a Piezo-based ceramic actuator, able to operate in corrosive environments. Further, at low voltage generated by the signal generator 210, the actuator 220 acts as a capacitor that can slowly charge up at low voltages to activate a choke mechanism, such as the flow regulator 218. It allows, with small voltage increments, for parts to move over large distances with a reasonable force. Ceramic actuator 220 also operates at very high temperature ranges, i.e. temperatures higher than 400°F, and even higher. The actuator 220 can be controlled to perform very small (nanometer) incremental movements (linear, rotational, multi-axes).

[0044] The entire autonomous flow control system 200 may be powered using power from surface via a cable or using a piezoelectric-based self-powering module that is distinct from the actuator 220 described above in which the system 200 generates a relatively low amount of electricity needed just for displacement of the actuator 220.

[0045] In general, the power for the system 200 can be supplied from the surface preferably using a single control line. Further, this power may then be used to amplify the signal from the signal generator 210 and thus provide more options for the type of actuator that can be used, or for other electronic components such as pressure and temperature gauges or piezo electric motors or DC motors. However, the MAG-ICD system 200 can be configured to generate power downhole and can thus operate without having to send power from surface through a control line, thus alleviating a need for long control lines running from surface that are prone to snap in extreme downhole conditions. [0046] An embodiment of an autonomous flow control system 300 with self- powering capabilities is shown in Figures 3a, 3b and 3c. Figure 3a illustrates the autonomous flow control system 300 when the flow is non-obstructed, and Figure 3b illustrates the autonomous flow control system 300 with the flow obstructed.

[0047] The autonomous flow control system 300 in this embodiment includes a device casing 302, that further includes an inlet 304 and a port 306 that perform the same operation as the inlet 204 and the port 208 in the autonomous flow control system 200. The system 300 further includes a downhole energy harvester 308 that generates power using the flow of the fluid and a signal generator 210 that receives power from the downhole energy harvester 308. The downhole energy harvester 308 generates enough power so that no power needs to be supplied from surface to the autonomous flow control system 300. Further, the downhole energy harvester 308 includes a fluid oscillator 310 and a piezo-electric power harvester (PEH) 312. The fluid oscillator 310 is based on a known technology and uses the bi-stable states of a jet, or a pair of jets, of fluid inside a specially designed flow chamber. Such an oscillator is able to generate sweeping or periodically oscillating jets of fluid at very high velocities without having any moving parts. The design of the fluid oscillator 310 is explained in detail with respect to Fig. 3c.

[0048] During the operation, the fluid enters in the system 300 through the inlet 304 and passes through the fluid oscillator 310 and then through the PEH 312 which generates considerable amounts of electric power. This electric power is then used to provide continuous energy to the flow regulator 218 to operate the flow controller 216 or to keep a capacitor 314 and/or battery pack charged. For example, the stored and live power can be used in combination to move the flow regulator 218 in the choke position when the signal generator 2 0 detects a water breakthrough.

[0049] Fluid oscillators such as the fluid oscillator 310, shown in some detail in Figure 3c, are based on existing technologies, and are highly suitable for integration into autonomous flow control system 300. Accordingly, Figure 3c illustrates a pair of individual fluid oscillators 310 that can be used to provide a pair of fluid streams to a pair of PEHs for generating the power. Further, each fluid oscillator 310 includes a main chamber 310-1 and a pair of side channels 310-2. The main chamber 310-1 and the side channels 310-2 are fluidically connected to each other so as to impart oscillations in the fluid flowing through the fluid oscillator 310. Further, the oscillating fluid exiting from the fluid oscillator 310 has enough fluid pressure to cause the PEH 312 to generate electric power. As may be understood, this type of power generator has no material moving parts and can be integrated in many other downhole tools and devices. The continuous electric power generated during the flow can even provide power to other wireless telemetry devices installed downhole, such as pressure and temperature gauges.

[0050] The autonomous flow control systems described with respect to Figures 2a-2c and Figures 3a-3c enable the controlling of inflow without moving sleeves, as control can be achieved using an advanced actuator technology, providing

ON/OFF variable flow control. In another embodiment, the autonomous flow control systems can be controlled from the surface. One such example of the autonomous flow control systems controllable from the surface is explained with respect to Figure. 4a-4c and 5a-5c.

[0051] Figures 4a-4c illustrate an embodiment of an autonomous flow control system 400 with an intelligent gate valve with ON/OFF capability and multiple choked positions. The valve 410 is a stand-alone device and can be controlled from the surface using a control line.

[0052] The autonomous flow control system 400 illustrated in Figures 4a-4c includes a device casing 402 that houses different components of the autonomous flow control system 400. The autonomous flow control system 400 also includes an inlet 404 that allows the fluid to ingress in the autonomous flow control system 400 and a port 406 that allows the fluid to egress from the autonomous flow control system 400 into the tubing string. The autonomous flow control system 400 also includes a choke 408 positioned between the inlet 404 and the port 406 to reduce the pressure of the fluid flowing in the tubing string. In one example, the size of a gap of the choke 408 can vary from 1 inch to 1/32 of an inch. The autonomous flow control system 400 also includes a valve 410 housed inside a valve housing 412, which valve 410 can move linearly along a length of the device casing 402 to either cover or uncover the port 406. In addition, the autonomous flow control system 400 includes rails 414 and valve supports 416 that facilitate the linear movement of the valve 410. In one example, the autonomous flow control system 400 includes an actuator (not shown) that powers the valve 410 to move along the length of the device casing 402. In one example, the actuator can be a linear Piezo walker motor to move the valve 410. Further, the autonomous flow control system 400 also includes a signal generator 418 that can receive an electric signal from the control line (not shown) to energize the actuator. In one example, the signal generator 418 can be a piezo-electric generator that energizes the actuator upon receipt of the signal from the surface. The autonomous flow control system 400 also includes additional electronic components, such as signal filters, amplifiers, batteries etc. to support the operation of the autonomous flow control system 400. 4a. In the port closed position, the valve 410 is over the fluid port 406. By providing a high frequency vibration close to the seal of the valve 410, the force required to open and close the valve 410 can be significantly reduced. These vibrations significantly reduce the friction to open and close the valve 410, resulting in a reduced power requirement.

[0053] Initially, the port 406 is covered by the valve 410 as shown in Figure 4a. In order to open the port 406, a signal is sent downhole to the autonomous flow control system 400 which is received by the signal generator 418, which further energizes the actuator. Once the actuator is energized, the actuator causes the valve 4 0 to exhibit a linear motion by moving away from the choke 408 thereby uncovering the port 406 as shown in Figure 4b. Further, the port 406 can be moved to the closed position again by sending another signal to energize the actuator to move the valve 410 towards the choke 408 to cover the port 406.

[0054] Another embodiment of an autonomous flow control system 500 with an intelligent valve is shown in Figure 5a-5c. The autonomous flow control system 500 has similar structural features as the autonomous flow control system 400 described with respect to Figure. 4a-4c. the autonomous flow control system 500 includes an inlet 502 that allows the fluid to ingress in the autonomous flow control system 500 and a port 504 that allows the fluid to egress from the autonomous flow control system 500 into the tubing string. As before a chock or a nozzle 506 is also provide in the flow path. In this embodiment, a gap of the nozzle 506 varies from 0.88" down to 1/32". Notably, unlike the linear moving valve as described in Figure. 4a-4c, the autonomous flow control system 500 includes a rotating disk valve 508 positioned between the inlet 502 and the port 504, which valve 508 can be rotated about an axis to variably impede the fluid flow to the port 504. The valve 508 includes a gate 508-1 that can move in and out of a path of the fluid flow to either prevent or allow the fluid flow to the port 504. The autonomous flow control system 500 also includes a controller 510 that can receive a signal from surface through a control line (not shown). The autonomous flow control system 500 also includes an actuator 512 coupled to the valve 508 using linkages 514 to rotate the valve 508. In one example, the linkages 514 can collectively be a crank mechanism that converts transverse motion of the actuator 512 to impart rotary motion to the valve 508. Further, in another example, the actuator 512 can be a piezo actuator to close or open the flow path to the port 504. Alternatively, the actuator 512 can be a "squiggle" motor known to the art, which has one moving part. Several other options for motors exist including other DC motors. It is the combination of the vibration generator and the motor technology that would enable the operation of the intelligent ICD valve 508.

[0055] The modular system described herein may also be used for implementing an inflow control system by using combinations of modules as described above, provided in each of a plurality of zones in a wellbore. Such a system could have controlled ON/OFF capability, providing an advanced intelligent completion system capable of autonomous response in case of a water breakthrough and can also provide flow regulation for a very large number of zones.

[0056] Compared to digital systems, analog electronics have traditionally been used in environments with temperatures of 325°F and possibly higher. Therefore, a system designed using analog electronics is adequate for the MAG-ICDs described herein. To achieve the 325°F rating, it may be possible to use advanced digital electronics and cooling systems. However, compared to digital systems, analog electronics can not only operate in higher temperature, but may also be much more reliable and are typically less costly. The downside of using only analog electronics is that the system may be less flexible. Digital electronics may be a more effective long-term solution and is typically preferred for the lower operating temperatures.

[0057] The ON/OFF and choking capability provided by the embodiments of the described autonomous flow control system can work in conjunction with the water detection technology provided by the MAG-ICD, and with downhole pressure and temperature gauges at some or all of the zones. This combination can provide an advanced intelligent completion system capable of surface controlled autonomous or interactive response to a water breakthrough and can also provide flow regulation for a very large number of devices.

[0058] As described in detail in US Patent Application US20170044868 referred to above, the parts of the autonomous flow control system described can be preferably arranged in a functional module and placed in a cassette 50,60 as shown in Figure 6. Figure 6 shows an example of a modular design for an ICD platform 600. The cassette 50,60 may be inserted in a pocket 61 formed in the wall of a tubular housing 62 that is placed at a desired location in the wellbore. The housing has a longitudinal inner bore, the pocket 61 having a fluid inlet port to allow fluid to pass from the area surrounding the respective autonomous flow control system into the inner bore of the housing through the pocket wall. Reference numeral 306 in Figures 3a, 3b, and reference numeral 406 in Figures 4a, and 4b illustrates an opening in the cassettes 50,60, which corresponds with the fluid port when the cassette 50,60 is inserted into the pocket.

[0059] The ends of the tubular housing 62 may be threaded or otherwise be adapted for connection to other tubulars in a string. In some embodiments, the container may be formed as a tubular that can then be mounted over another tubular. Figure 6 shows the basic pipe at 63 and a screen provided over the pipe at 64.

[0060] Two or more cassettes may be inserted in the pocket 61 to control the inflow; multiple cassettes may be connected in series or in parallel providing unprecedented flexibility of the control functions provided for the respective inflow.

[0061] The pocket 61 that receives the cassette 50,60 with the functional module/s includes a retaining area having a compatible form factor build to retain the module in the pocket 61. In addition to the cassette 50, 60 with intelligent functional modules as shown at 50, 60, the system may also be equipped with additional cassettes. They vary from housing basic nozzle modules all the way to ICD modules that can autonomously reduce water and/or gas production or even reduce cross-flow without any moving parts. These and other functional modules may be integrated into single or multiple cassettes.

[0062] For example, cassettes may include, and are not limited to functional modules with pressure/temperature gauges, multi-phase flow meters, tracer modules, downhole power generators, etc. Besides the other functions that each functional module may be able to perform, the core of the modular ICD technology is to provide many different ICD styles and pressure drop regimes. As an example of a combination cassette, a chocking device and an ON/OFF module may be integrated in a single cassette.

[0063] Each of these functional cassettes is designed to fit inside the pocket 61. All cassettes with one or more functional modules include highly erosion/corrosion resistant materials such as ceramic and take the entire pressure drop inside the cassette.

[0064] By utilizing the modular ICD platform 600, controlling inflow no longer requires sleeves, but can utilize actuator technology, providing ON/OFF and variable flow control, and optionally, the following additional advantages.

• Combined with the downhole water detection provided by the MAG-ICD module, one or more of the following functionalities are achieved by this modular ICD design:

Surface controlled adjustable downhole choke, with ON/OFF and 14 choked positions.

Adjustable chokes may also be infinitely adjustable and include a position indicator.

• External power supply can be provided through a TEC (Tubing Encased Conductor) line. Two or more TEC lines may be advantageous or desired.

• Several sleeves per zone are possible.

• Pressure/temperature gauges can be inserted in the cassettes.

• Water break through detection can be signaled to surface.

[0065] Although the invention has been described with respect to specific embodiments thereof, these embodiments are merely illustrative, and not restrictive of the invention. Rather, the description is intended to describe illustrative embodiments, features and functions in order to provide a person of ordinary skill in the art context to understand the invention without limiting the invention to any particularly described embodiment, feature, or function. While specific

embodiments of, and examples for, the invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the invention, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications may be made to the invention in light of the foregoing description of illustrated embodiments of the invention and are to be included within the spirit and scope of the invention. Thus, while the invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of embodiments of the invention will be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the invention.

[0066] Reference throughout this specification to "one embodiment", "an embodiment", or "a specific embodiment" or similar terminology means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment and may not necessarily be present in all embodiments. Thus, respective appearances of the phrases "in one embodiment", "in an embodiment", or "in a specific embodiment" or similar terminology in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any particular embodiment may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the invention.

[0067] In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that an embodiment may be able to be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, components, systems, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the invention. While the invention may be illustrated by using a particular embodiment, this is not and does not limit the invention to any particular embodiment and a person of ordinary skill in the art will recognize that additional embodiments are readily understandable and are a part of this invention.

[0068] As used herein, the terms "comprises," "comprising," "includes,"

"including," "has," "having," or any other variation thereof, are intended to cover a non- exclusive inclusion. For example, a process, product, article, or apparatus that comprises a list of elements is not necessarily limited only those elements but may include other elements not expressly listed or inherent to such process, product, article, or apparatus. Furthermore, the term "or" as used herein is generally intended to mean "and/or" unless otherwise indicated. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). As used herein, a term preceded by "a" or "an" (and "the" when antecedent basis is "a" or "an") includes both singular and plural of such term, unless clearly indicated otherwise (i.e., that the reference "a" or "an" clearly indicates only the singular or only the plural). Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.

Claims

What is claimed is:

1. An autonomous flow control system for controlling a liquid's flow through a flow path established between a base pipe and a subterranean formation, comprising:

a signal generator adapted to a produce an electrical signal across a portion of the flow path based on the conductivity of the liquid, upon detecting presence of a component of the liquid in the flow path

a flow controller adapted to restrict the flow path in response to the electrical signal.

2. The system of claim 1 , wherein the flow controller comprises a flow regulator adapted to trigger an actuator to restrict the flow path.

3. The system of claim 1 , wherein the flow controller further comprises a valve for allowing or restricting the liquid flow, and a vibration generator for generating vibrations that reduce a force required to operate the valve.

4. The system of claim 1 , wherein the flow controller is adapted to restrict the flow path at various levels of blockage, based on an amount of the liquid component detected in the flow path.

5. The system of claim 1 , wherein the flow controller is adapted to trigger closing of the flow path when the electrical signal indicates the liquid component in the flow path is water.

6. The system of claim 5, wherein the flow controller is adapted to partially close the flow path when the electrical signal indicates a water breakthrough.

7. The system of claim 1 , wherein the signal generator comprises:

a tubular body adapted to be placed on the base pipe around the flow path; one or more magnets on the tubular body to create a magnetic field along the flow path; and one or more electrodes interspaced on the tubular body with the one or more magnets for producing the electric signal upon presence of the liquid component in the flow path.

8. The system of claim 7, wherein the magnets is one of permanent magnets and electromagnets.

9. The system of claim 7, wherein the magnets are rare Earth Magnets.

10. The system of claim 7, wherein the magnets have high resistance to at least erosion and corrosion.

11. The system of claim 2, wherein the actuator is a piezo-electric actuator, adapted to operate in corrosive environments.

12. The system of claim 1 , further comprising a power supply.

13. The system of claim 1 , further comprising a downhole energy harvester for generating and storing electricity.

14. The system of claim 13, wherein the downhole energy harvester comprises a fluid oscillator adapted to increase a velocity of the fluid flow to a piezo-electric power harvester (PEH), and a capacitor for storing electrical power received from the piezoelectric power harvester.

15. The system of claim 13, wherein the downhole energy harvester comprises a nozzle adapted to increase the velocity of the fluid flow to a piezo-electric power harvester, and a capacitor for storing the electric power received from the piezoelectric power harvester.

16. The system of claim 1 further comprising at least one of: pressure gauges, temperature gauges, tracer modules, signal generators, multi-phase flow meters, or nozzles.

7. A method of advanced flow control for controlling liquid flow in a flow path established between a base pipe and a subterranean formation, comprising:

generating an electrical signal across a portion of the flow path upon detecting presence of a water component in the flow path based on conductivity of water; and restricting the flow path in response to the electrical signal.