Apparatus and method for selective inflow control using nuclear magnetic resonance measurements for hydrocarbon production without water

An apparatus for extracting a fluid from a formation includes an inflow control device (ICD) coupled to a production tubular disposed in a borehole penetrating the formation and configured to control flow into the production tubular and a nuclear magnetic resonance (NMR) front-end component assembly disposed in the borehole, the NMR front-end component assembly having a sensitive volume in a flow path leading to and/or coming through the ICD. The apparatus also includes a controller receiving input from an NMR electronics module coupled to the NMR front-end component assembly and providing output to the ICD based on the input from the NMR electronics module.

BACKGROUND

Hydrocarbons are typically extracted using a production tubular that penetrates a reservoir in a subsurface formation. The production tubular has openings providing a fluid communication with the reservoir and through at least some of which hydrocarbons may enter the tubular. Some reservoirs however have regions or pockets of water and if the production tubular is located in a water region, then water can also enter the production tubular and be pumped to the surface. Unfortunately, extracting both hydrocarbon and water through the production tubular can increase the cost of hydrocarbon production as the hydrocarbon must be separated from the water at the surface. Hence, it would be well received in the hydrocarbon recovery industry if techniques were developed to improve hydrocarbon production.

BRIEF SUMMARY

Disclosed is an apparatus for extracting a fluid from a formation, the apparatus includes: an inflow control device (ICD) coupled to a production tubular disposed in a borehole penetrating the formation and configured to control flow into the production tubular; a nuclear magnetic resonance (NMR) front-end component assembly disposed in the borehole, the NMR front-end component assembly having a sensitive volume in a flow path leading to and/or coming through the ICD; and a controller receiving input from an NMR electronics module coupled to the NMR front-end component assembly and providing output to the ICD based on the input from the NMR electronics module.

Also disclosed is a method for extracting a fluid from a formation, the method includes: performing a nuclear magnetic resonance (NMR) measurement with a sensitive volume in a flow path leading to and/or coming through an inflow control device (ICD) coupled to a production tubular disposed in a borehole penetrating the formation using an NMR front-end component assembly disposed in the borehole to provide NMR data; and controlling the ICD based on the NMR data.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method presented herein by way of exemplification and not limitation with reference to the figures.

Disclosed are embodiments of apparatuses and methods for producing hydrocarbons such as oil from a reservoir in a formation using a production tubular in which water intrusion is prevented or limited. The embodiments involve having inflow control devices (ICDs) at multiple locations along a production tubular and a nuclear magnetic resonance (NMR) front-end component assembly located in proximity to each ICD. The NMR front-end component assembly includes at least a magnet and an antenna. Alternatively, the earth's magnetic field may be used in lieu of or in addition to the magnetic field of the magnet. Each NMR front-end component assembly has a sensitive volume leading to and/or through the corresponding ICD. For example, the sensitive volume may be in the production tubular downstream of the corresponding ICD or in the formation near to an inlet of the corresponding ICD. By interrogating the sensitive volume, the presence of hydrocarbons or water that is being introduced or can be introduced into the corresponding ICD can be identified. ICDs that have or can have water introduced into them can be remotely closed and ICDs that have or can have hydrocarbons introduced into them can be remotely opened. As a result, the production tubular will extract only or mostly hydrocarbons without water contamination.

FIG. 1illustrates a cross-sectional view of a borehole2penetrating the earth3having a formation4, which contains a reservoir of hydrocarbons. The borehole2is lined with a casing5. A production tubular6is disposed within the casing5. Surface production equipment7is disposed at the surface of the earth and is configured to extract and process extracted hydrocarbons such as oil. The production equipment7may include pumps, valves, piping, filtering, and storage facilities. The production tubular6includes multiple inflow control devices (ICDs)8, such as valves, through which formation fluids can enter the production tubular6. Each ICD8includes an actuator9to remotely open or close the ICD8. In one or more embodiments, the actuator9is an electro-mechanical actuator that converts electric power to mechanical movement of the ICD8. Other types of actuators may also be used such as pneumatic actuators and hydraulic actuators. Each ICD8can be controlled by a downhole controller15and/or by a surface controller16such as a computer processing system.

A nuclear magnetic resonance (NMR) front-end component assembly10is located in proximity of each ICD8such that each NMR front-end component assembly10has a sensitive volume that is located downstream of the corresponding ICD8and/or in a region of the formation4that can supply formation fluid to the corresponding ICD8. It can be appreciated that the closer the sensitive volume is to the corresponding ICD8, the lesser the likelihood (or amount) of unwanted formation fluid such as water entering the production tubular7.

Each NMR front-end component assembly10includes an antenna (see antenna11inFIGS. 2 and 3) and a magnet (see magnet12inFIGS. 2 and 3). The magnet is configured to impose a magnetic field in a location referred to as a sensitive volume20in which an NMR experiment or measurement is performed. To be clear, the term “sensitive volume” relates to a spatial volume in which an NMR experiment or measurement is performed to determine a property of a material inside of the volume. The magnetic field polarizes nuclear spins of nuclei such as protons in the sensitive volume. The antenna is configured to transmit a series of precisely timed bursts or pulses of radio-frequency (RF) electromagnetic energy to the nuclear spins in the sensitive volume20to cause them to precess in the magnetic field. The antenna is also configured to receive NMR signals due to the precession of the nuclei in order to perform the NMR experiment or measurement. A downhole NMR electronics module13is coupled to the antenna and configured to transmit the RF pulses and receive the NMR signals via the antenna.

As a result of the interaction of the RF pulses with the nuclear spins, the nuclear spins precess at what is known as the Larmor frequency and generate alternating magnetic fields. The alternating magnetic fields known as echoes induce the NMR signals in the antenna. The NMR signals are received by the downhole NMR electronics module13coupled to the antenna. The downhole NMR electronics module13includes a processing circuit that is configured to output calibrated NMR signal measurements of the material in the sensitive volume using the NMR signals.

Long trains of echoes or echo trains can be recorded. The decays of the echo trains are caused by the so-called T2 relaxation, also known as transverse or spin-spin relaxation. The NMR measurements yield transverse relaxation times T2, which are exponential decay time constants that correspond to a characteristic or property of the material in the sensitive volume. Transverse relaxation relates to the loss of phase coherence of the nuclei or protons in the sensitive volume while precessing about the static magnetic field during an NMR measurement or experiment. There is not one single value of T2 for formation fluids but a wide distribution of values lying anywhere between fractions of a millisecond and several seconds for example. The quantitative distribution of T2 values is the principal output of the downhole NMR electronics module13. In alternative embodiments, low field NMR may be used and/or T1 relaxation values may be output from the downhole NMR electronics module13. In that NMR tools for obtaining a quantitative distribution of T2 values and/or T1 values are known in the art, they are not discussed herein in further detail.

From the quantitative distribution of T2 values, the material within the sensitive volume can be identified as being water or hydrocarbons by the downhole NMR electronics module13, the controller15, and/or16by comparing the quantitative distribution of T2 values to reference standards for hydrocarbons (e.g., oil) and water for example. The reference standards can be obtained by testing and/or by analysis using NMR data known in the art.

A signal identifying the material in the sensitive volume can be transmitted by telemetry, such as a fiber optic cable in a non-limiting embodiment, to the downhole controller15and/or the surface controller16. The downhole controller15and/or the surface controller16are configured to open ICDs8whose sensitive volume contains hydrocarbons and to close ICDs8whose sensitive volume contains water based on the quantitative distribution of T2 values that identify the reservoir fluid. Communication between the downhole controller15and/or the surface controller16and the corresponding ICDs8can be by optical signal and/or electrical signal using an appropriate medium in non-limiting embodiments.

It can be appreciated that there may be a single downhole NMR electronics module13for each NMR front-end component assembly10or there may be a single downhole NMR electronics module13for a certain number of NMR front-end component assemblies10. In embodiments having multiple NMR front-end component assemblies10associated with a single downhole NMR electronics module13, the module13can be switched to each assembly10in a sequence so that NMR data is obtained from all associated assemblies10.

FIG. 2depicts aspects of an embodiment of a plurality of NMR front-end component assemblies10having the sensitive volume20inside the production tubular6. In the embodiment ofFIG. 2, an antenna11is a coil of a conductor wrapped around the production tubular7. Similarly, a magnet12includes two magnets with each of the magnets12wrapped around the production tubular7and imposing a magnetic field inside the production tubular7in the sensitive volume. In this embodiment, the downhole NMR electronics module13is embodied as an electronic sub and is coupled to the multiple NMR front-end component assemblies10illustrated. In an alternative embodiment, the NMR front-end component assemblies10may be configured to have their sensitive volumes external to the production tubular7in the vicinity of an inlet of each corresponding ICD8. As such, each antenna11may have its centerline axis rotated 90° from the axes illustrated inFIG. 2. Similarly, the magnets12may have their magnetization rotated 90° to magnetize the external sensitive volume.

FIG. 3depicts aspects of another embodiment having a plurality of NMR front-end component assemblies10.FIG. 3illustrates the casing5being cemented in place with perforations through the casing5and cement where the ICDs8have inlets. In the embodiment ofFIG. 3, the ICDs8are electro-mechanical valves. In the embodiment ofFIG. 3, electrical power is supplied locally by a small turbine generator32that is powered by a flow of production fluid through a flow diverter31. Alternatively or in addition to the generator32, a battery33may supply the electrical power. The sensitive volumes20may be within or external to the production tubular7depending on the orientation of the NMR front-end component assemblies10.

FIG. 4is a flow chart for a method40for extracting a fluid from a formation. Block41calls for performing a nuclear magnetic resonance (NMR) measurement with a sensitive volume in a flow path leading to and/or coming through an inflow control device (ICD) coupled to a production tubular disposed in a borehole penetrating the formation using an NMR front-end component assembly disposed in the borehole to provide NMR data. The sensitive volume may be at least one of (i) within the production tubular and downstream of the ICD (i.e., flow path coming through the ICD) and (ii) in a region having an inlet to the ICD (i.e., flow path leading to the ICD). The NMR front-end component assembly may be disposed in the vicinity of the ICD (such as within 10 feet) and may include at least a magnet to provide a static magnetic field in the sensitive volume and an antenna to transmit RF energy into the sensitive volume and receive NMR signals from the sensitive volume. Alternatively, the earth's magnetic field may be used to provide the static magnetic field and the front-end component assembly may include the antenna and not the magnet. The ICD may include a plurality of ICDs with each ICD having an associated NMR front-end component assembly. For example, if there are ten ICDs, then there will be at least ten NMR front-end component assemblies.

Block42calls for controlling the ICD based on the NMR data. Controlling the ICD may include closing the ICD when the NMR measurement indicates water is in the sensitive volume and opening the ICD when the NMR measurement indicates hydrocarbons such as oil are in the sensitive volume. In one or more embodiments, the ICD is controlled automatically by a controller that receives the NMR data from an NMR electronic module that is coupled to the NMR front-end component assembly.

The method40may also include pumping the fluid that enters the production tubular to the surface.

The method40may also include imposing a magnetic field in the sensitive volume using a magnet that surrounds the production tubular and/or the earth's magnetic field.

The method40may also include transmitting a series of radio-frequency electromagnetic pulses into the sensitive volume using an antenna having a coil of conductive material that surrounds the production tubular and receiving NMR signals from the sensitive volume using the antenna.

In the method40, the ICD may be embodied as a remotely-controlled valve having an actuator and the method40may also include sending a signal to the actuator to open the remotely-controlled valve in response the NMR data indicating hydrocarbons are in the sensitive volume.

In the method40, the ICD may be embodied as a remotely-controlled valve having an actuator and the method40may also include sending a signal to the actuator to close the remotely-controlled valve in response the NMR data indicating water is in the sensitive volume.

The method40may also include generating electric power using a turbine-generator disposed in a path of a flow diverter coupled to the production tubular, the turbine-generator being coupled to an NMR electronics module that operates the NMR front-end component assembly.

The disclosure herein provides several advantages. One advantage is that only the type of fluid desired (e.g., oil) will be extracted from the formation, thus eliminating or reducing the need and associated cost to separate other types of fluid (e.g., water) from the desired fluid at the surface. Another advantage is that only NMR front-end component assemblies are required at each of the ICDs, thus obviating the need and associated cost of having separate dedicated NMR electronics modules associated with each ICD. Another advantage is when using water injection to increase the oil recovery. In this case, the advantage to using this method is early detection of when the injected water is flooding the reservoir, thereby saving time and costs.

Embodiment 1: An apparatus for extracting a fluid from a formation, the apparatus comprising: an inflow control device (ICD) coupled to a production tubular disposed in a borehole penetrating the formation and configured to control flow into the production tubular, a nuclear magnetic resonance (NMR) front-end component assembly disposed in the borehole, the NMR front-end component assembly having a sensitive volume in a flow path leading to and/or coming through the ICD, and a controller receiving input from an NMR electronics module coupled to the NMR front-end component assembly and providing output to the ICD based on the input from the NMR electronics module.

Embodiment 2: The apparatus according to any previous embodiment, wherein the sensitive volume is at least one of (i) within the production tubular and downstream of the ICD and (ii) a region having an inlet to the ICD.

Embodiment 3: The apparatus according to any previous embodiment, wherein the NMR front-end component assembly comprises a magnet.

Embodiment 4: The apparatus according to any previous embodiment, wherein the magnet surrounds the production tubular.

Embodiment 5: The apparatus according to any previous embodiment, wherein the NMR front-end component assembly comprises an antenna.

Embodiment 6: The apparatus according to any previous embodiment, wherein the antenna comprises a coil of a conductive material surrounding the production tubular.

Embodiment 7: The apparatus according to any previous embodiment, wherein the inflow control device comprises a remotely-controlled valve.

Embodiment 8: The apparatus according to any previous embodiment, wherein the remotely-controlled valve comprises an electro-mechanical actuator.

Embodiment 9: The apparatus according to any previous embodiment, further comprising a flow diverter coupled to the production tubular to divert flow from the production tubular and a turbine-generator disposed in a path of the flow diverter to generate electric power.

Embodiment 10: A method for extracting a fluid from a formation, the method comprising: performing a nuclear magnetic resonance (NMR) measurement with a sensitive volume in a flow path leading to and/or coming through an inflow control device (ICD) coupled to a production tubular disposed in a borehole penetrating the formation using an NMR front-end component assembly disposed in the borehole to provide NMR data, and controlling the ICD based on the NMR data.

Embodiment 11: The method according to any previous embodiment, wherein the sensitive volume is at least one of (i) within the production tubular and downstream of ICD and (ii) a region having an inlet to the ICD.

Embodiment 12: The method according to any previous embodiment, further comprising imposing a magnetic field in the sensitive volume using a magnet that surrounds the production tubular and/or using the earth's magnetic field in the sensitive volume.

Embodiment 13: The method according to any previous embodiment, further comprising transmitting a series of radio-frequency electromagnetic pulses into the sensitive volume using an antenna having a coil of conductive material that surrounds the production tubular and receiving NMR signals from the sensitive volume using the antenna.

Embodiment 14: The method according to any previous embodiment, wherein the ICD comprises a remotely-controlled valve having an actuator and the method further comprises sending a signal to the actuator to open the remotely-controlled valve in response the NMR data indicating hydrocarbons are in the sensitive volume.

Embodiment 15: The method according to any previous embodiment, wherein the hydrocarbons comprise oil.

Embodiment 16: The method according to any previous embodiment, wherein the ICD comprises a remotely-controlled valve having an actuator and the method further comprises sending a signal to the actuator to close the remotely-controlled valve in response the NMR data indicating water is in the sensitive volume.

Embodiment 17: The method according to any previous embodiment, further comprising generating electric power using a turbine-generator disposed in a path of a flow diverter coupled to the production tubular and/or a battery, the turbine-generator and/or battery being coupled to an NMR electronics module that operates the NMR front-end component assembly.

Further, various other components may be included and called upon for providing for aspects of the teachings herein. For example, a power supply, magnet, electromagnet, sensor, electrode, transmitter, receiver, transceiver, antenna, controller, optical unit or components, electrical unit, electrochemical unit, battery, energy storage unit, or electromechanical unit may be included in support of the various aspects discussed herein or in support of other functions beyond this disclosure.

Elements of the embodiments have been introduced with either the articles “a” or “an.” The articles are intended to mean that there are one or more of the elements. The terms “including” and “having” and the like are intended to be inclusive such that there may be additional elements other than the elements listed. The conjunction “or” when used with a list of at least two terms is intended to mean any term or combination of terms. The term “configured” relates one or more structural limitations of a device that are required for the device to perform the function or operation for which the device is configured.

The flow diagram depicted herein is just an example. There may be many variations to this diagram or the steps (or operations) described therein without departing from the scope of the invention. For example, operations may be performed in another order or other operations may be performed at certain points without changing the specific disclosed sequence of operations with respect to each other. All of these variations are considered a part of the claimed invention.

The disclosure illustratively disclosed herein may be practiced in the absence of any element which is not specifically disclosed herein.

While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.