Patent Application
20250034991
The present invention relates to apparatus and method for monitoring well fluid conditions. Aspects of the invention include a monitoring system to control and monitor the release of tracer and measure and monitor characteristics and parameters of well fluids in a production well and/or an injection well.
The efficient recovery of hydrocarbons from a reservoir is a difficult and complex process which requires an understanding of the flow conditions of the hydrocarbons in the reservoir and the well.
Downhole tracers installed in production wells have been proven for estimating which fluids flow in which parts of the well, and at which flow rates so that hydrocarbons may be recovered as efficiently as possible. Different tracers have been placed in different influx zones to a production completion installed in a well to understand which zones contribute to flow.
A problem of known downhole tracer techniques is that the downhole conditions can affect the flow of tracers downhole. As an example, pressure variations can exist in the well which can result in situations where tracers travel upstream or flow into other zones in the formation which is known as cross-flow. Cross flow presents uncertainties and can affect the accuracy of flow rate analysis.
Further problems of accurate flow rate analysis can occur due to the different volumetric and phase behavior of produced hydrocarbons as they travel from the reservoir up through the well to surface.
It is an object of an aspect of the present invention to provide a monitoring system which is capable on measuring and monitoring conditions of a well and controlling the release of tracers in the well.
It is another object of the present invention to measure the conditions of a well before, during and/or after selectively releasing tracer into the production flow to allow flow measurement and wellbore inflow profiles to be calculated and monitored.
It is an object of the present invention to accurately calculate and/or adjust wellbore profiles based on tracer flow information and measured flow conditions of a well before.
According to a first aspect of the invention, there is provided a system for monitoring a well, the system comprising;
The at least one monitoring system may be configured to measure and/or monitor at least one property, condition and/or characteristic of a well. The at least one monitoring system may be configured to measure and/or monitor at least one property, condition and/or characteristic at least one well fluid. The at least one monitoring system may be configured to measure and/or monitor at least one property, condition and/or characteristic of at least a component of a well fluid. The at least one at least one property, condition and/or characteristic of a well or well fluid may be selected from the group of pressure, temperature, volume, density, viscosity, salinity, flow rate, influx rate of a well fluid, tracer type and/or tracer concentration. The well fluid may be oil, gas and/or water. The system may be a downhole system. The components of the well monitoring system may be located downhole. The system may be modular with one or more of the modules located downhole.
The at least one sensor may be selected from the group comprising pressure sensor, temperature sensor, volume sensor, flow rate sensor, density sensor, optical sensor and/or or spectrophotometric sensor. The at least one sensor may be arranged or installed in the well, in or on the formation, in the annulus and/or in or on the production tubing. The at least one sensor may be arranged or installed in or on completion equipment. The at least one sensor may be arranged or installed in or on the at least one tracer release system and/or at least one communication system.
The system may comprise a sampler device configured for downhole sampling of at least one well fluid. The system may comprise a downhole probe. The downhole probe may be part of the at least one sensor system. The downhole probe may be configured to detect, monitor and/or measure at least one property, condition and/or characteristic of a well or at least one well fluid. The probe may comprise optical sensor, optical fibers or spectrophotometric sensor.
The at least one communication system may comprise at least one transmitter and at least one receiver. The at least one transmitter may be a wired or wireless transmitter. The at least one receiver may be a wired or wireless receiver.
The at least one communication system may be configured to transmit information from the sensor system and/or tracer release system to the surface, to another well monitoring system and/or to a downhole communication system. The information may include data relating to pressure, temperature, volume, density, viscosity, salinity, flow rate and/or influx rate of a well fluid. The information may include the status of the sensor system and/or tracer release system.
The system may comprise a control unit. The communication system may be part of a control unit. The communication system may be configured to receive signals from surface, a control unit, another well monitoring system and/or a downhole communication system to control the operation of the at least one sensor system and/or tracer release system.
The well may be an injection well. The well may be a production well. The at least one tracer release system, the at least one sensor system and/or the communication system may be modular. The communication system may be configured to transmit and/or receive information from more than one sensor system and/or more than one tracer release system in the monitoring system.
The at least one tracer release apparatus or a component of the at least one tracer release apparatus may be installed or replaced. The at least one tracer release apparatus or a component of the at least one tracer release apparatus may be conveyed down the well, wellbore, tubing or through the production tubing by wireline, slickline, coiled tubing, drill pipe or similar conveyance.
The at least one tracer release apparatus may be controlled to selectively release tracer into an injection well, reservoir, production well, and/or production flow to allow flow measurement and wellbore inflow profiles to be calculated and monitored. The at least one tracer release apparatus may be configured to release at least one tracer. The at least one tracer may be a liquid, solid or gas. The at least one tracer release apparatus may be configured to build up a high or increased concentration of tracer and selectively releasing the tracer without requiring the well to be shut in. The at least one tracer release apparatus may be configured to release a high concentration of tracer as a tracer cloud which can be detected in the well fluid at surface and/or downstream of release. This may also allow controlled exposure of the tracer source to well fluid to extend the lifespan of the tracer downhole.
The at least one tracer release apparatus may comprise:
The at least one tracer release apparatus may comprise at least one inlet. The at least one inlet may be in fluid communication with the at least one tracer chamber. The at least one valve may be configured to selectively control the flow of fluid through the at least one inlet.
The control unit may be configured to control the actuation of the at least one valve to selectively open and close the at least one inlet and/or outlet to control the flow of fluid through the at least one inlet and/or outlet.
The at least one valve may be configured to selectively open and close the at least one inlet between a fully open position, a fully closed position, or to an intermediate position between the fully open and fully closed position. The at least one valve may be configured to selectively open and close the at least one outlet between a fully open position, a fully closed position, or to an intermediate position between the fully open and fully closed position.
The at least one valve may be operated to control flow and vary the area of openings for flow through the at least one inlet and/or through the at least one outlet. The tracer material may be configured to selectively release tracer molecules from the tracer material into a fluid into the tracer chamber on contact with a particular well fluid. Preferably the tracer material is designed to release tracer molecules into the tracer chamber when the tracer material is exposed to a target fluid i.e. oil, gas or water. The tracer material may be a solid, liquid or gas.
Preferably the least one tracer chamber has a flow passage with a fluid volume. The fluid volume may be a fixed fluid volume. The dimensions of the fluid volume may be designed to produce a known volume of fluid with increased concentration of tracer molecules when the fluid volume is shut in. The release of increase concentration of tracer molecules as a tracer cloud may create a tracer transient which may be detectable as a tracer response spike at the downstream detection point.
The shut-in fluid volume may be enriched or saturated with tracer molecules. The fluid volume dimensions may be designed for different tracer types or different target fluid types. Different fluid volume dimensions may be used depending on the detection limit of the tracer. For example, a tracer with a low detection limit may require a higher volume of enriched tracer fluid to be released to allow detection.
The dimensions of the fluid volume may be adjusted or configured depending on the desired operation or lifespan of the tracer release apparatus. For example, a tracer release apparatus designed for a long downhole lifespan may require a smaller fluid volume to restrict the amount of tracer released with each release operation.
The tracer material may be selected from the group comprising chemical, fluorescent, phosphorescent, magnetic, DNA and radioactive compounds. The tracer material may comprise chemical tracers selected from the group comprising perfluorinated hydrocarbons or perfluoroethers. The perfluorinated hydrocarbons may be selected from the group of perfluoro butane (PB), perfluoro methyl cyclopentane (PMCP), perfluoro methyl cyclohexane (PMCH). The tracer material may be chemically immobilized within and/or to the tracer chamber. The tracer material may comprise a tracer and a carrier. The carrier may be a matrix material. The matrix material may be a polymeric material.
The tracer may be chemically immobilized within and/or to the carrier. The tracer material may be chemically immobilized by a chemical interaction between the tracer and the carrier. The tracer material may be chemically immobilized in a way that it releases tracer molecules or particles in the presence of a chemical trigger. By varying the chemical interaction between the tracer and the polymer the release mechanism and the rate of release of tracer molecules from the tracer material may be controlled. Preferably the tracer is released from the tracer carrier with an even release rate.
The carrier may be a selected from poly methyl methacrylates (PMMA), poly methylcrylates, poly ethylenglycols (PEG), poly lactic acid (PLA) or poly glycolic acid (PGA) commercially available polymers or copolymers thereof. The carrier may be selected from polymers with higher rates of tracer molecules release such as polyethylene and polypropylene.
The tracer may be physically dispersed and/or physically encapsulated in the carrier. The tracer material may release tracer molecules into fluid by dissolution or degradation of the carrier and/or the tracer into the fluid. The carrier may be selected to controllable degrade on contact with a fluid. The carrier may be selected to degrade by hydrolysis of the carrier. The tracer and/or the carrier may be fluid specific such that the tracer molecules will be released from the tracer material as a response to a contact with a target liquid. The tracers and/or the carrier may be chemically intelligent such that tracer molecules will be released from the tracer material as a response of specific events, e.g. they respond to an oil flow (oil-active) but show no response to a water flow (water-resistant). Another group of chemical compounds can be placed in the same region, which release tracers in water flow (water-active) but show no response to an oil flow (oil-resistant). The tracers and/or the carrier may be chemically intelligent such that tracer molecules will be released from the tracer material as a response the exposure of the tracer material to a well fluid and/or a target well fluid.
The tracer molecules may be detected and its concentration measured by different techniques such as optical detection, optical fibers, spectrophotometric methods, PCR techniques combined with sequential analysis, chromatographic methods or radioactivity analysis. The invention is not restricted to the above-mentioned techniques.
The tracer molecules may be detected and its concentration measured by sampling production fluid. The sampling may be conducted at the one or more sampling times. The sampling may be conducted downhole downstream of the tracer release apparatus or at surface. The sampling may be conducted downhole. Samples may be collected for later analysis. The tracer molecules may be detected by a detection device such a probe. The detection device may be located downstream of the tracer release apparatus. The detection device may be located downhole or at surface. The detection device may facilitate real time monitoring and/or analysis of the tracer in the production fluid. The tracer material may be disposed in the tracer chamber to allow fluid to contact the tracer material as it passes around the tracer material in the tracer chamber.
The at least one valve may be a mechanical valve or thermodynamic valve. The at least one valve may be a controllable valve. The at least one valve may be configured to selectively open and/or close in response to a well event. The at least one valve may be set to be normally open or normally closed. The at least one valve may be a flapper valve, throttle valve or a sleeve valve. The at least one valve may be adjustably set to be normally open or normally closed. The at least one valve may comprise a biasing mechanism. The at least one valve may be balanced or biased by a biasing mechanism. The biasing mechanism may be a spring. The biasing mechanism may be a coil spring, a wave spring or a gas spring such as a nitrogen gas spring. The biasing mechanism may be adjusted to set the actuation threshold of the valve. Preferably the valve is a biased by a spring which may be adjustable by changing the type, length or tension of the spring. The actuation threshold of the valve may be set.
The valve settings of the at least one valve may be adjusted via direct connection from surface to the valve. The valve settings may be adjusted via an intervention operation by lowering an intervention device by wireline, slickline, coiled tubing, drill pipe or similar conveyance to manipulate and adjust the setting on the at least one valve.
Tracer released from the tracer release apparatus may create a characteristic signal called a flush-out signal. The flush-out signal has a peak concentration followed by the decay of the concentration. The decay of the concentration after the peak may be expressed by a slowly decaying function such as exponential function or power law function. The coefficient in the functions describing the steepness of the decay is proportional to the fluid velocity inside the tracer release apparatus and thus the fluid velocity inside the tracer release apparatus can be calculated based on the measured tracer concentration decay curve. Steeper curve, i.e., shorter flush-out time, corresponds to the higher fluid velocity inside the tracer release apparatus.
The duration of the tracer signal may be captured by sampling or real time measurement. The signal should be long enough that it is not destroyed by the dispersion during the travel to the detection point which may be located after the upper completion and a long tie-back. Tracer release and dispersion may be modelled by flow models. The dispersion of the signal during the travel to the detection point may be compensated by modelling based on the well geometry and/or a model of the well.
The monitoring system may comprise two or more tracer release apparatus. The two or more tracer release apparatus may be configured to be installed or arranged at different positions along the well. In a production well the two or more tracer release apparatus may be positioned downstream of an influx zone. In an injection well the two or more tracer release apparatus may be positioned upstream of a reservoir injection zone. Each of the two or more tracer release apparatus may comprise a distinct tracer material.
The monitoring system may comprise two or more sensor systems. The two or more sensor systems may be configured to be installed or arranged at different positions along the well. The monitoring system may comprise two or more communication systems. The two or more communication systems may be configured to be installed or arranged at different positions along the well.
The system may comprise two or more monitoring systems. The two or more monitoring systems may be configured for connection to a downhole or production tubing at different positions along the downhole or production tubing. The two or more monitoring systems or components thereof may be positioned downstream of an influx zone. The two or more monitoring systems or components thereof may be positioned upstream of an influx zone. The at least one tracer release apparatus of the respective monitoring systems may comprise a distinct tracer material. The system may be retrofitted into an existing tubing. The system may be arranged, retrievable, installed, replaced and/or adjusted by wireline, slickline, coiled tubing, drill pipe or similar conveyance. The system and/or components of the system may be installed or replaced and may be conveyed through the production tubing by wireline, slickline, coiled tubing, drill pipe or similar conveyance. The system and/or components of the system may be conveyed onto at least one landing nipple. The at least one landing nipple may have ports in communication with the production tubing and/or the annulus.
According to a second aspect of the invention, there is provided a system for monitoring a well, the system comprising;
Embodiments of the second aspect of the invention may include one or more features of the first aspect of the invention or its embodiments, or vice versa.
According to a third aspect of the invention there is provided a method of monitoring a well, comprising;
The method may comprise measuring at least one property, condition and/or characteristic of a well. The method may comprise measuring at least one property, condition and/or characteristic of at least one well fluid in the well. The method may comprise measuring at least one property, condition and/or characteristic of a component of at least one well fluid. The method may comprise monitoring the at least one property, condition and/or characteristic of a well or at least one well fluid in the well. The method may comprise monitoring the at least one property, condition and/or characteristic of a well or at least one well fluid in the well over time. The at least one monitoring system may be configured to measure and/or monitor at least one property, condition and/or characteristic of a well. The at least one monitoring system may be configured to measure and/or monitor at least one property, condition and/or characteristic at least one well fluid.
The at least one property, condition and/or characteristic of a well or well fluid may be selected from the group of pressure, temperature, volume, density, viscosity, salinity, flow rate and/or influx rate of a well fluid, tracer content, tracer type and/or tracer concentration. The well fluid may be oil, gas and/or water. The method may comprise inferring the condition of the well and/or reservoir from at least one measured property, condition and/or characteristic of at least one well fluid. The condition of a well and/or reservoir may be defined by temperature, pressure, flow rate, well fluid composition, density, viscosity and/or salinity.
The method may comprise collecting information on the condition of the well and transmitting the information to the surface. The method may comprise collecting information on the condition of the status of the tracer release system and transmitting the information to the surface. The method may comprise transmitting a signal to the surface confirming the release of tracer from the tracer release system. The method may comprise releasing tracer from the at least one tracer release system in response to a command from surface, a command from a control unit or in response to a well condition.
The method may comprise collecting information on the condition of the well before, during and/or after actuating the at least one tracer release system. The method may comprise receiving the control signal from surface. The method may comprise receiving the control signal from a control unit. The method may comprise receiving the control signal from another at least one well monitoring system.
The method may comprise detecting the presence of tracer downstream of the tracer release apparatus or at surface. The method may comprise measuring a concentration of a released tracer in at least one well fluid by sampling at one or more sampling times.
The method may comprise analyzing characteristics of the tracer release, sampling time, and/or cumulative produced volume of the influx volumes from different influx zones.
Embodiments of the third aspect of the invention may include one or more features of the first or second aspects of the invention or their embodiments, or vice versa.
According to a fourth aspect of the invention there is provided a method of monitoring a reservoir, comprising;
at least one tracer release system;
at least one sensor system comprising at least one sensor; and
at least one communication system comprising at least one transmitter and at least one receiver;
The method may comprise measuring and/or monitoring at least one property, condition and/or characteristic of a well or at least one well fluid in the well before, during and/or after releasing tracer into the well.
The monitoring system may comprise two or more tracer release apparatus. The monitoring system may comprise two or more sensor systems. The monitoring system may comprise two or more communication systems. The two or more tracer release apparatus, sensor systems and/or communication systems may be configured to be installed or arranged at different positions along the well.
The well may be a production well. The method may comprise providing components of the at least one monitoring system in known levels of a production well.
The well may be an injection well. The method may comprise injecting released tracer into the reservoir. The method may comprise providing components of the at least one modular monitoring system in an injector well and/or a producer well.
The method may comprise collecting information on the condition of the well and transmitting the information to the surface. The method may comprise collecting information on the condition of the status of the tracer release system and transmitting the information to the surface. The method may comprise transmitting a signal to the surface confirming the release of tracer from the tracer release system.
Embodiments of the fourth aspect of the invention may include one or more features of the first to third aspects of the invention or their embodiments, or vice versa.
According to a fifth aspect of the invention, there is provided a modular system for monitoring a well, the system comprising;
The at least one tracer release module, at least one sensor module and/or at least one communication module may be installed or arrange in the same of different positions in the well.
The well may be a production well. The well may be an injector well. The well may be a producer injector well. Components of the modular system may be arranged in the injector and/or in the producer well. Some components of the modular system may be arranged in an injector well and other components of the modular system may be arranged in an associated producer well.
Embodiments of the fifth aspect of the invention may include one or more features of the first to fourth aspects of the invention or their embodiments, or vice versa.
According to a sixth aspect of the invention there is provided a method of monitoring a well, comprising;
The method may comprise measuring at least one property, condition and/or characteristic of a well or measuring at least one property, condition and/or characteristic of at least one well fluid.
The well may be a production well. The method may comprise measuring and/or monitoring at least one property, condition and/or characteristic of a well or well fluid in the production well. The well may be an injection well. The method may comprise measuring and/or monitoring at least one property, condition and/or characteristic of a well or well fluid in the injector well and/or producer well.
Embodiments of the sixth aspect of the invention may include one or more features of the first to fifth aspects of the invention or their embodiments, or vice versa.
According to a seventh aspect of the invention there is provided a well comprising;
Embodiments of the seventh aspect of the invention may include one or more features of the first to sixth aspects of the invention or their embodiments, or vice versa.
According to an eighth aspect of the invention, there is provided a method of measuring at least one characteristic of the well fluid in a well comprising at least one well monitoring system in the well, wherein each well monitoring system comprises;
The method may comprise actuating the at least one tracer release system to release tracer into the well. The method may comprise actuating the at least one sensor system to measure at least one characteristic of the well fluid before, during and/or after actuating the at least one tracer release system. The method may comprise measuring a characteristic of the well fluid downhole and/or at surface.
The method may comprise sampling well fluid. The well may be an injector well. The method may comprise sampling well fluid in the injector well and/or a producer well. The well may be a production well. The method may comprise sampling well fluid in the production well. The sampling may be conducted at one or more sampling times. The sampling may be conducted downhole downstream, upstream and/or adjacent to the at least one well monitoring assembly. The sampling may be conducted at surface. The sampling may be conducted downhole. Samples may be collected for later analysis. The sampling may be conducted to measure at least one characteristic or parameter of the well fluid. The sampling may be conducted to measure the pressure, temperature and/or volume of the well fluid. The sampling may be conducted to measure the type and/or concentration of tracer in the sample.
Embodiments of the eighth aspect of the invention may include one or more features of the first to seventh aspects of the invention or their embodiments, or vice versa.
According to a ninth aspect of the invention, there is provided a method of monitoring a well, comprising;
The method may comprise transmitting information from the at least one sensor system and/or at least one tracer release system to surface, to another well monitoring system and/or to a downhole communication system.
The method may comprise measuring at least one property, condition and/or characteristic of a well, at least one well fluid, and/or a component of at least one well fluid. The at least one property, condition and/or characteristic of a well, at least one well fluid, and/or a component of at least one well fluid may be selected from the group including pressure, temperature, volume, density, flow rate, tracer type and/or tracer concentration.
Embodiments of the ninth aspect of the invention may include one or more features of the first to eighth aspects of the invention or their embodiments, or vice versa.
According to a tenth aspect of the invention, there is provided a method of monitoring a well wherein the well comprises at least one well monitoring system installed or arranged in the well, the at least one well monitoring system comprising:
The method may comprise measuring at least one property, condition and/or characteristic of a well, at least one well fluid, and/or a component of at least one well fluid. The at least one property, condition and/or characteristic of a well, at least one well fluid, and/or a component of at least one well fluid may be selected from the group including pressure, temperature, volume, density, flow rate, tracer type and/or tracer concentration. Embodiments of the tenth aspect of the invention may include one or more features of the first to ninth aspects of the invention or their embodiments, or vice versa.
There will now be described, by way of example only, various embodiments of the invention with reference to the following drawings (like reference numerals referring to like features) in which:
In this example the monitoring system is configured to be installed on a production tubing. It will be appreciated that the monitoring system or components of the monitoring system may be installed or arranged as part of the completion at different parts of the well. Alternatively, the monitoring system or components of the monitoring system may be lowered into the well via coiled tubing, wireline, slickline, drill pipe or a similar conveyance.
As shown in
The control unit is configured to control the actuation of the sensors. Parameters and/or conditions of the well are measured by the sensors in this example temperature and pressure data which is relayed to the surface via the control unit and wireless transmitter.
The system 15 has a tracer release apparatus 24. In this example, the tracer release apparatus is arranged at or near a well fluid influx location from a reservoir. The tracer release apparatus is in communication with the control unit. The control unit is configured to control the actuation of the tracer release apparatus. In this example the control unit is configured to receive signals from surface. The signal may be used to control the actuation of the tracer release apparatus via the wireless receiver. Additionally, or alternatively, the control unit may have a pre-set program to actuate the tracer release apparatus at a set frequency and/or duration. The signals from surface may be used to adjust the frequency and/or duration of the actuation of the tracer release apparatus and release of tracer. The control unit is configured to transmit data from the tracer release apparatus to the surface via the wireless transmitter. The data may include the status of the tracer release apparatus, confirmation of tracer release, the amount of remaining tracer and/or the amount of battery life.
The control unit is configured to receive and/or transmit data to and/or from the sensors. The system may transmit the sensor and/or tracer release apparatus data in real-time. In one example the system may produce or transmit an alarm when a certain parameter is approached or exceeded. For example, an alarm may be produced or transmitted when the well temperature exceeds a pre-set threshold level or when the tracer or battery level reaches a pre-set lower level.
If the sensor data shows exceeded pre-set limits in one section of the well, this may improve the interpretation of tracer flow data measured at surface.
When actuated by the control unit, the tracer release apparatus releases tracer into the production flow. The tracer type and concentration are measured at a point downstream which may be downhole or at surface to provide information on which influx locations are producing and the rates of influx.
Optionally the system may comprise a downhole sampler. The downhole sampler may be configured to obtain a sample of the fluid in the well under the well conditions. The downhole sampler may be configured to measure temperature, pressure, flow rate, well fluid composition, density, viscosity and/or salinity. Additionally, or alternatively the downhole sampler may be configured to determine the type and/or concentration of a tracer in the sample. The actuation of the downhole sampler may be controlled by the control unit.
In use, each of the four monitoring systems takes measurements of the well conditions by monitoring at least one property or characteristic of at least one well fluid such as pressure, temperature and density. The communication system in each system transmits the monitoring data to the surface via the wireless transmitter so that an operator has real time information on the well conditions in the different regions of the well.
When a tracer release operation is required or desired either on command from surface or programmed tracer release, a signal is transmitted from the monitoring system to confirm tracer release has occurred. The monitoring system may monitor well conditions before, after and/or during the tracer release event. In this example, the communication system receives a release signal from surface. The control unit sends a command signal to actuate the tracer release apparatus. In this example the control unit actuates the tracer release apparatus for a pre-set duration. In this example the control unit is configured to transmit data from the tracer release apparatus to the surface via the wireless transmitter. The data transmitted may include confirmation of actuation of the tracer release apparatus. The data transmitted may include sensor data monitoring one or more well conditions in the injector well before, during and/or after the release of tracer into the well.
Analysis may be performed on the measured data of the at least one property or characteristic of at least one well fluid and/or well to characterize the reservoir. As an example, the measured concentration of tracer in the well fluid and/or time delay between the tracer release in the production well and its detection at surface or known downstream location may provide information on flow conditions of the well and reservoir.
The tracer release apparatus has an inlet 118 and an outlet 120 in fluid communication with a production pipe 12. The tracer release apparatus 100 surrounding the production tubing has an annulus tracer chamber 121 with a fluid volume 122 which comprises a tracer material 124. The tracer material may be disposed in the fluid volume to allow fluid to contact the tracer material and pass around the tracer material in the fluid volume 122. The tracer material 124 is designed to release tracer molecules or particles when exposed to a target well fluid i.e. oil, gas or water.
A valve assembly 126 has a movable closure member for selectively opening and closing the outlet aperture 120a to control the flow of fluid from the fluid volume 122 to the production pipe. In the examples show in
To open the valve, the control unit sends a first command signal. The valve is actuated to open the outlet allowing fluid and high concentration of tracer to pass through the outlet into the production tubing. The high concentration of the tracer is flushed out of the tracer chamber by the inflow of production fluid into the tracer chamber via the inlet. The high concentration tracer in the form of a tracer cloud is carried to the surface. The control unit optionally transmits a signal to surface that the valve has been actuated to an open condition.
After a desired duration, the control unit sends a second command signal to close the valve. The valve is actuated which closes the outlet 120. Fluid in the fluid volume 122 is prevented from exiting the tracer chamber. The tracer material 126 remains exposed to a volume of fluid over the period of time that the valve assembly is closed building up a high concentration of the tracer particles 126a in the fluid volume. Depending on the tracer type, its release rate into the target fluid and the period of time the valve assembly is closed determines the saturation or enrichment level of the fluid volume with tracer. The control unit optionally transmits a signal to surface that the valve has been actuated to a closed condition.
The control unit is configured to control the frequency at which the opens and closes the valve. The frequency may be pre-set before the apparatus is positioned downhole. It will be appreciated that the frequency may be adjusted by a signal from surface and/or in response to sensor data. Optionally the control unit may be configured to control the opening and closing of the valve on command.
The tracer transients formed by the shut-in of the tracer release apparatus, build up tracer concentration and subsequent release propagate to the surface as high concentration tracer clouds, slugs or shots. The tracer transients are driven by the velocity field in the well. The topside arrivals of the onset of the different tracers, or the full transient of the different tracers, can be used to estimate the downhole velocity field. From the velocity field the inflow profile may be calculated.
The above embodiment has applications in wells where sand mitigation may be an issue at high production rates.
The tracer apparatus 210 has an injection port 218 in fluid communication with the well. The tracer is configured to be injected out of the apparatus into the well through the injection port 218. In this example the apparatus has only one injection port. However, it will be appreciated that the apparatus may have two or more injection ports. A valve assembly 220 is located between the tracer reservoir 216 and the at least one injection port 218. The valve assembly 220 has an electrically operated solenoid actuator 222, valve spring 224 and a piston 226. The solenoid actuator 222 and valve spring 224 are attached to one end 226a of the piston. A second end 226b of the piston is configured to move in a tracer release chamber 230 which is in fluid communication with the tracer reservoir 216 via a conduit 234.
In operation when a tracer injection is required the control unit receives a control signal. In this example the control signal is generated from a pre-programmed timer in the control unit. However, it will be appreciated that the control signal may be generated from surface or in response to a well event.
The control signal sends a command signal to the actuate the solenoid actuator 222. This moves the piston to a retracted position in direction “B” as shown in
After a pre-set period of time the control signal sends a command signal to de-actuate the solenoid actuator 222. The valve spring 224 which is a compression spring moves the piston in direction “A” as shown in
The volume of tracer in the tracer release chamber may be replenished from tracer traveling to the tracer release chamber from the tracer reservoir 16 via the conduit 232. It will be appreciated that the tracer in the tracer reservoir may be pressurized to assist the travel into the tracer release chamber. It will be appreciated that a pump may be used to pressurize the tracer in the tracer reservoir or to force the tracer into the tracer release chamber from the tracer reservoir 216 via the conduit 234. It will also be appreciated that the piston and/or tracer release chamber may be designed such that retraction of the piston creates a draw effect on the tracer in the conduit 234 which draws the tracer from the reservoir into the tracer release chamber. It will be appreciated that instead of a pump, an accumulator may be used that will maintain a pre-set pressure over the lifespan of the tool. This may allow the tracer to be released at a constant pressure and/or rate irrespective of the amount of tracer remaining in the tracer reservoir. The piston accumulator assembly may be located between the tracer reservoir and the tracer release chamber. The duration and/or frequency of the actuation and de-actuation of the solenoid actuator 222 is controlled by the control unit. The control unit may be configured to send command signal with a pulse width of between 0.05 seconds and 30 seconds.
As shown in
The monitoring system 300 comprises sensors 316 configured to measure at least one well condition in the injector well 310, in this example a temperature sensor to measure temperature and a pressure sensor to measure pressure. The sensors are in communication with a control unit 318. In this example the control unit comprises a communication system 319 which comprise a wireless transmitter and a wireless receiver. The control unit is configured to control the actuation of the sensors. Parameters and/or conditions of the well are measured by the sensors. In this example temperature and pressure data which is relayed to the surface via the control unit and wireless transmitter. It will be appreciated that other downhole sensors may be used and other properties, conditions and/or characteristics of a well or well fluid monitored.
In use, to inject tracer into the reservoir the communication system in the control unit receives a release signal from surface. The control unit sends a command signal to actuate the tracer release apparatus. In this example the control unit actuates the tracer release apparatus for a pre-set duration. In this example the control unit is configured to transmit data from the tracer release apparatus to the surface via the wireless transmitter. The data transmitted may include confirmation of actuation of the tracer release apparatus. The data transmitted may also include sensor data monitoring one or more well conditions in the injector well before, during and/or after the release of tracer into the well.
After the tracer 330 is released into the injector well. Fluid such as water is pumped into the injection well to pump the released tracer from the injection well into the reservoir as shown by arrows “A” in
One or more producer wells are monitored for the type and concentration of tracer. In this example one producer well 312 is shown. Produced fluid from the reservoir into the producer is sampled to measure at least one condition, characteristic or parameter of the well fluid. In this example the sampling is conducted to measure the type and/or concentration of tracer in the well fluid sample. However, additionally other conditions, characteristics or parameters such as pressure, temperature and/or volume of the well fluid may be sampled. In this example the system monitors the sensor data and/or tracer release apparatus data in real-time. The sensor data and/or tracer release apparatus data may be analyzed to measure and/or monitor at least one property, condition and/or characteristic of the well fluid or the well.
It will be appreciated that alternative means of lowering and raising the monitoring system 400 in the injection well 410 may include wireline, slickline, drill pipe or a similar conveyance. The monitoring system 400 is lowered into the well. Each monitoring apparatus 400 has a tracer release apparatus 424. The tracer release apparatus is lowered to a known level in the well. The subsequent monitoring, tracer release and characterizing of the reservoir, injector well and/or producer well are the same as and will be understood from
In the above example shown in
In the above examples the monitoring system is shown as single unit installed or arranged on the production tubing or coiled tubing. However, it will be appreciated that the monitor system may be a modular system. A tracer release apparatus module may be located on the production tubing or coiled tubing at a different position to the sensor module. Likewise, each of the respective control unit modules, communication system modules including transmitter and/or receiver may be separate modules located at different positions to one another. The various modules of the modular monitoring system may be located at separate positions in the same or different wells (in the case of an injection or interwell system).
Each modular monitoring system has a sensor module 516a and 516b configured to measure at least one well fluid condition, such as temperature, pressure or density. The sensors are in communication with a control unit module 518a and 518b. Each modular monitoring system has a communication system 519a and 519b which comprises a wireless transmitter 520 and a wireless receiver 522. The communication system may be a separate from but in communication with the control unit.
In use, each of the two modular monitoring systems takes measurements of the well conditions by monitoring conditions or characteristics of at least one well fluid such as pressure, temperature, density and tracer concentration. The control units in each system transmits the monitoring data to the surface via the wireless transmitter so that an operator has real time information on the well conditions in the different regions of the well. Each of the communication system 519a and 519b receives data from the surface including actuation instructions for sensors or tracer release apparatus for each modular monitoring system.
In the above example it is described that each monitoring system has an individual control unit. However, it will be appreciated that a central control unit may be used which is in communication with the sensors and tracer release apparatus of the various monitoring systems. The central control unit may receive data from each of monitoring systems or selected monitoring systems including sensor data and the status of the tracer release apparatus.
The central control unit may transmit the received data from each of monitoring system or selected monitoring systems to the surface. The central control unit may receive data from the surface including actuation instructions for sensors or tracer release apparatus for each of monitoring system or selected monitoring systems. The control unit may transmit the received data from the surface to the sensors and/or tracer release apparatus for each of monitoring system or selected monitoring systems.
As shown in
In use, the modular monitoring system takes measurements of the injector well conditions by monitoring characteristics of at least one well fluid such as pressure, temperature, density, water volume and/or tracer concentration. The control units in each system transmits the monitoring data to the surface via the wireless transmitter so that an operator has real time information on the well conditions in the different regions of the well. The communication system 619 receives data from the surface including actuation instructions for sensors or the tracer release apparatus module.
After the tracer 630 is released into the injector well. Water is pumped into the injection well to pump the released tracer from the injection well into the reservoir as shown by arrows “A” in
The injector well has components of the modular monitoring system 715 installed in or on the central tubing in the same manner as described in relation to
As shown in
In use, the modular monitoring system 715 takes measurements of the injector well conditions by monitoring at least one condition or characteristics of at least one well fluid such as pressure, temperature, density and/or water volume. The control unit transmits the monitoring data to the surface via the wireless transmitter so that an operator has real time information on the well conditions in the different regions of the injector well. The communication system 719 receives data from the surface including actuation instructions for sensors or the tracer release apparatus module. Optionally one or more tracer release apparatus module may also be present in the producer well.
After the tracer 730 is released into the injector well. Water is pumped into the injection well to pump the released tracer from the injection well into the reservoir as shown by arrows “A” in
In the producer well the well conditions are monitored by measurement of the conditions and/or characteristics of at least one well fluid such as pressure, temperature and/or density, using sensor module 716a. The control unit 718a transmits the monitoring data to the surface via the wireless transmitter 720a so that an operator has real time information on the producer well conditions. The tracer type and concentration may be measured and the time delay between tracer release and arrival and the concentration levels measured at the producer well may provide well flow conditions and/or volume in the injector well, reservoir and/or producer well. Analysis may also provide information on the inflow profile in the producer well.
In the above examples shown in
Each one of the two or more monitoring systems may have a separate control unit. The control of the sensors and tracer release systems for each monitoring system would be understood from the description above.
It will be appreciated that a central control unit may be used which is in communication with the sensors and tracer release apparatus of the various monitoring systems. The central control unit may receive data from each of monitoring systems or selected monitoring systems including sensor data and the status of the tracer release apparatus.
The central control unit may transmit the received data from each of monitoring system or selected monitoring systems to the surface. The central control unit may receive data from the surface including actuation instructions for sensors or tracer release apparatus for each of monitoring system or selected monitoring systems. The control unit may transmit the received data from the surface to the sensors and/or tracer release apparatus for each of monitoring system or selected monitoring systems.
It will be appreciated that the monitoring system may be used for interwell and production well applications. However, in an interwell application the monitoring system may monitor addition characteristics or parameters for example the amount of water injected into the formation at a zone or total reservoir length. The tracer release may be configured that no tracer is released until threshold parameters in the well conditions are met for the tracer release to be triggered.
The detection, analysis and/or interpretation of tracer data in well fluids may be considered as separate methods from one another and performed at different times or jurisdictions. The detection, analysis and/or interpretation of tracer in well fluid may be separate methods to release of tracer from the tracer release apparatus and/or the collection of samples. The sensor data and/or tracer release apparatus data may be analyzed to measure and/or monitor at least one property, condition and/or characteristic of the well fluid or the well.
Embodiments of the monitoring system may measure and/or monitor conditions of a well and control the release of tracers in the well. The conditions of may be monitored before during and/or after selectively releasing tracer into the production flow to allow accurate flow measurements and wellbore inflow profiles to be calculated and monitored. Throughout the specification, unless the context demands otherwise, the terms ‘comprise’ or ‘include’, or variations such as ‘comprises’ or ‘comprising’, ‘includes’ or ‘including’ will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. Furthermore, relative terms such as “up”, “down”, “top”, “bottom”, “upper”, “lower”, “upward”, “downward”, “horizontal”, “vertical”, “extend”, “retract” and the like are used herein to indicate directions and locations as they apply to the appended drawings and will not be construed as limiting the invention and features thereof to particular arrangements or orientations.
The foregoing description of the invention has been presented for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, further modifications or improvements may be incorporated without departing from the scope of the invention as defined by the appended claims
| Number | Date | Country | Kind |
|---|---|---|---|
| 2117920.5 | Dec 2021 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/085218 | 12/9/2022 | WO |
