This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
In subsea operations, hydrocarbon fluids (e.g., oil and natural gas) may be obtained from a subterranean geologic formation, referred to as a reservoir, by drilling a well that penetrates the subterranean geologic formation. Telemetry systems may be used in the oil & gas industry to communicate information in real-time between the subsurface to the surface while drilling (e.g. mud pulse telemetry, electromagnetic telemetry) or between subsea vehicle to surface vehicles (e.g. underwater communication). For example, drilling data may transmit from the subsurface to the surface, as well as data from subsea vehicles (e.g., inspection data). It would be beneficial to improve communications systems and methods of communication.
In an embodiment, telemetry system is provided. The telemetry system includes a transmitter configured to convert digital bits representative of oil and gas operations into an analog signal and to transmit the analog signal via a communications channel. The telemetry system further includes a receiver configured to receive the analog signal and to convert the analog signal into output digital bits via an encoder, wherein the receiver comprises one or more receiver components trained via machine learning to process the analog signals for improved communications.
In an embodiment, a method is provided. The method includes converting digital bits representative of underwater machine operations into an analog signal via a transmitter. The method further includes transmitting the analog signal via a communications channel, and receiving, via a receiver, the analog signal. The method additionally includes converting the analog signal into output digital bits via an encoder, wherein the receiver comprises one or more receiver components trained via machine learning to process the analog signals for improved communications.
In an embodiment, non-transitory computer readable media storing instructions is provided. The instructions when executed cause a processor to convert digital bits representative of underwater machine operations into an analog signal via a transmitter, and to transmit the analog signal via a communications channel. The instructions further cause the processor to receive, via a receiver, the analog signal and to convert the analog signal into output digital bits via an encoder, wherein the receiver comprises one or more receiver components trained via machine learning to process the analog signals for improved communications.
Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and:
In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
One or more specific embodiments of the present disclosure will be described below. These described embodiments are only exemplary of the present disclosure. Additionally, in an effort to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments, the articles “a,” “an,” “the,” “said,” and the like, are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” “having,” and the like are intended to be inclusive and mean that there may be additional elements other than the listed elements. The use of “top,” “bottom,” “above,” “below,” and variations of these terms is made for convenience, but does not require any particular orientation of the components relative to some fixed reference, such as the direction of gravity. The term “communications” encompasses one-way transmissions, two-way interchange of information, or a combination thereof.
The disclosure herein generally involves a system and methodology for adaptive communications via certain machine learning techniques, such as neural networks. The adaptive communications systems described herein may include, for example, telemetry systems. Different telemetry systems may used in oil and gas applications, such as Logging While Drilling (LWD) telemetry in different forms (mud pulse, electromagnetic, acoustic, and the like), which provides for a technology suitable for lower-cost Measuring While Drilling (MWD)/LWD operations. Another communications system, such as an untethered underwater communications, may be a promising solution to enable the inspection of subsea assets by underwater untethered robots without the risk of a tether becoming caught or entangled. These communications systems may each include a propagation channel that is not precisely known, and a signal generation that may become distorted by digital to analog and analog to digital chains present in the communication systems. In addition, telemetry may become extremely sensitive to environmental noise. For example, depending on the operational conditions (e.g., salinity, distance, water temperature, thermoclines, and the like), the signal power measured at surface can be several orders of magnitude smaller than the noise, thus preventing reliable demodulation of the telemetry signal. Because of more limited power available on the transmitter side, increasing the energy of the signal may not always be possible, and may only provide marginal improvements on the energy level at surface. Conversely, preventing the noise in the environment (e.g., underwater environment) is a difficult task due to the large variety of potential noise sources.
According to certain embodiments, the communications systems described herein include machine learning systems suitable for adapting all or part of the telecommunication building blocks (e.g., receiver building blocks, transmitter building blocks) to a specific communications platform of interest. For example, neural networks may be trained (e.g., via supervised training, semi-supervised training, unsupervised training, or a combination thereof) to create one or more machine learning agents that may provide tuning “packages” to one or more telecommunication building blocks that encompass specific hardware (hardware-in-the-loop) as well as specific software (software-in-the-loop) of interest. The learning agents may compensate for adverse effects of physical communications layers without using an explicit model of signal propagation. The learning agents may additionally learn a more efficient tradeoff between cancelling of noise and equalization of the receive signal. Further, internal parameters (e.g., communication systems parameters) may be adjusted based changes in a propagation channel.
In certain embodiments, a reinforcement learning (RL) for hyperparameters tuning agent is provided. The tuning agent may use RL techniques as further described below to tune parameters used by receivers and transmitters. For example, receiver parameters that may be tuned via RL may include equalizer size (e.g., number of feedforward taps, number of feedback taps, or a combination thereof), tracking loop parameters, threshold (e.g., correlation coefficient for synchronization), filtering parameters (e.g., frequency of notch filter, bandpass filter parameters, stopband filter parameters, and so on), or a combination thereof. Transmitter parameters that may be tuned via RL may include a central frequency, a constellation map, a data rate/bandwidth, error correction code mode and related parameters, transmitter pulse shape, power, or a combination thereof. It is to be noted that the receiver tuning may be independent and thus not need communication or cooperation with the transmitter. Likewise, the transmitter tuning, except for pulse shape, may be independent and not need communication or cooperation with the receiver.
In certain embodiments, machine learning systems may be trained to classify and segment a spectrum into specific regions where noise may be strong and thus lead to interference. The classification and/or segmenting techniques may analyze different channels and provide regions of interest bounded by a time interval (e.g., between a start time Tstart and a stop time Tstop), a frequency interval (e.g. between a start frequency fstart and a stop frequency fstop), and or a physical region (e.g., a square or other shape of a volume of ocean at a certain depth). Information detected by the classification and/or segmenting techniques may then be used to avoid time-frequency (and/or physical) regions where the strongest noise is present or use this information as prior knowledge for subsequent noise cancelation algorithms.
In certain embodiments, complex hardware and/or channels may be modeled. For example, Generative Adversarial Networks (GANs) may be used to generate data sets which may include modeling the communications channel (e.g., subsea environment) as well as modeling a complete communications chain. Indeed, a generator and discriminator pair may be used to simulate more realistic datasets, including propagation channel(s), which may then be used by other embodiments described herein for training, for example. Accordingly, an end-to-end learning with hardware in the loop may be provided, which may use machine learning to tune telecommunication building blocks such as demodulation, filters, packet synchronization, equalization, decoding, error correcting codes, and the like.
Turning now to
Also shown are communication nodes 30, 32, 34. In certain embodiments, the nodes 30, 32, 34 may provide for retransmission of data (e.g., data “hopping”), thus enabling for longer transmission distances and improved transmission energy. The communication nodes 30, 32, and/or 34 may be included, for example, in untethered remote underwater vehicles. However, it is to be understood that the communication nodes 30, 32, and/or 34 may be additionally or alternatively included in other electronics not part of a remote underwater vehicle. By providing for communicative systems 24, 28, 30, 32, 34, a mesh network may be created, suitable for communications (e.g., one-way communication, two-way communication) between members of the mesh network and the surface 14. By using the techniques described herein, the mesh network may be an adaptive communications system, which may learn and adapt to environmental conditions, to specific hardware, to specific software, or to a combination thereof, thus providing for end-to-end learning, with hardware and/or software in the loop.
It may be beneficial to describe a transmission of data, as illustrated in
The transducer in a receiver 62 may sense the transmitted analog signal, demodulate the analog signal, and convert the analog signal into a digital signal. The digital signal may include, for example, one or more measurements (e.g., channels) 62. A decoder 64 may then convert the digital signal into output data 66 (e.g., digital data bits). Systems and algorithms used for creating encoded bits usually do not consider the hardware or the presence of specific noise signature(s) in the environment. Consequently, the overall performance of the communication system is likely degraded compared to the expected performance (or theoretical performance if additive white Gaussian noise (AWGN) is assumed). The systems and algorithms may be optimized for a specific environment in terms of the electronics (i.e. hardware used), a propagation model and a noise. However, this approach may be relatively expensive and time-consuming as the conception of good propagation models by a human may be a tedious task.
As an alternative, the techniques described herein may leverage machine learning to train certain agents based on certain targeted platforms of interest (hardware and software in the loop) in order to “tune” or otherwise specialize the telecommunication algorithms to specific hardware and/or software platform(s). This machine learning approach may not require specialized expertise as the more optimal parameters are directly learned from the data.
The machine learning approach described herein may have several applications. For example, and turning now to
Advantageously, an embodiment of a machine learning process for data packet detection is shown in
Max pooling layers 162 may then be used, for example, to calculate a maximum value for each patch in a feature map. A fully connected layer 164 may then be used to transition from the feature maps to an output prediction. Accordingly, a linear classifier neural network 166, for example, may be created, suitable for making a classification decision (e.g., preamble found, preamble not found) based on input data, such as the data packet 100 shown in
In the depicted embodiment, graphs 250, 252 include axis 254 and 256 respectively, of a ratio of feedback (FB) taps to total taps. The graphs 250, 252 additionally include axis 258 and 260, respectively, of a mean signal-to-noise (SNR) in decibels. Graph 250 shows 1 and 2 channel embodiments, while graph 252 shows 3 and 4 channel embodiments. Reinforcement learning (RL) may be used for hyperparameter tuning to determine a more optimal number of FB taps, for example, for a given mean SNR. Telecommunication receivers may depend on many parameters that may need to be constantly adjusted to match a specific environment. Performances of the receiver have been found to be highly dependent on the allocation of the feedforward and feedback taps as illustrated. The optimal parameters may depend on the specific communication channel being used as well as the geometry of a receiver array. Consequently, these parameters are dynamic and may need to be adjusted manually during each deployment scenario. This manual optimization is typically done by experienced engineering personnel, who typically receive extensive training. In many cases the manual optimization may not be done, leading to the performance of the communications system not being fully utilized.
As an alternative to manual adjustment of the parameters, the techniques described herein include applying a Reinforcement Learning technique for training an agent to automate the optimization of the parameters in a given receiver configuration. An agent architecture is shown in
The agent 314 may reading information from “observables” 316. The observables 316 may include intermediate data in the receiver 310 pipeline. This intermediate data may include the time traces available after each processing block inside the receiver 314, such as time traces of packet detection, time traces of a constellation phase shift, soft symbols before and after error correcting codes, and so on. Hyperparameters 318 may be any parameters of interest which may be adjusted to improve the performance of the receiver or to otherwise “tune” the receiver. For example, hyperparameters 318 may include parameters of a syncword detection to adjust to the background noise level, an allocation of feedforward and feedback filters to compensate the channel 306, and/or parameters of tracking loops to compensate for the variation in propagation speed (e.g., doppler).
A neural network used in the agent 314 may be trained offline using a large dataset of test signals where the transmitted symbols are known. The training dataset is representative of the real operational conditions encountered in field deployment and a reward function may be defined such that the correct recovery of the decoded bits is rewarded while incorrect recovery is penalized. The agent 314 is then trained until it learns how to leverage the observables to maximize the reward. In use, the agent 314 may then adaptively tune the receiver 310 and/or decoder 320, thus improving signal receipt and conversion into the digital bits 322.
In cases of multiple channel receivers, it may be appropriate to pick a limited number of channels to perform the decoding. Limiting the number of channels reduces the complexity of the decoder and it may avoid adding noise in the decoder. Selecting the relevant channels to feed the decoder is a non-trivial task. It depends heavily on the spatio-temporal aspects of the channel. For example, when the channel 306 is saltwater, salinity, temperature, detritus, flows, and so on, may affect signals over time. The techniques described herein include using reinforcement learning to adaptively pick the channels to use. A typical example is the use of one or multiple channel receiver arrays as shown in
More specifically,
Additionally, some parameters of the transmitters must often be adjusted to achieve a more robust and optimal telemetry. Those parameters comprise but are not limited to the central frequency of the telemetry signal, the bandwidth, the data rate, the pulse shaping, the error-correcting codes, the packet maximal size, the preamble characteristics. Other parameters may include parameters used in the actual signal modulation, e.g., parameters used for PSK, FSK, QAM, OFDM, ASK, and the like. Under the assumption of a bi-directional communication link, it may be possible to exchange side information between the transmitter 304 and the receiver 310/decoder 320. Hence, the receiver/decoder may inform the transmitter 304 with information useful in improving communications. At least a couple of communication system architectures may be used to optimize the transmitter parameters.
In one architecture, RL is executed in the receiver 304 using a set of indicators to assess the reward such as signal quality, telemetry statistics, and the like. Decisions to change the transmitter 304 parameters are sent from the transmitter 304 to the receiver 310 using the bi-directional link. In a second architecture, RL is executed in the transmitter 304 using information that is sent from the receiver 310 to the transmitter 304 using the bi-directional link. Both architectures may also be used in combination.
Turning now to
As shown in
Alternately, a machine learning technique may be used for the communication systems described herein where an automated system has been trained to classify and to segment the spectrogram into specific regions where noise is strong and could interfere with the region of interest. Turning now to
For example, machine learning be used to identify noises, such as the noises 456-468, as well as regions (e.g., frequencies, times, geographic locations) where the noises 456-458 occur. Indeed, the illustrated spectrum sensing analyzes different channels 510 and provides regions of interest bounded by a time interval [Tstart-Tstop] and/or a frequency interval [fstart-fstop] 512. Information 512 detected by the spectrum sensing may be consequently used to avoid time-frequency regions where the strongest noise is present or use this information as prior knowledge for subsequent noise cancelation. This technique may be used with all other techniques described herein, including combinations with the agent 314.
Telecommunication receivers may traditionally use “pulse shaping filters” to reduce the bandwidth occupancy of the telecommunication signal. A choice for pulse shaping is to use the root-raised cosine filter 550 shown in
As an alternative or additional to pulse shaping, machine learning techniques described herein may learn a more optimal filter by performing a system-in-a-loop learning, using production hardware and software in the transmitter, the receiver, the decoder, and so on, as part of the learning chain. An embodiment of a communication systems architecture that may use system-in-a-loop learning is shown in
In the depicted embodiment, digital bits 602 may be used an input by a transmitter 604 for conversion into analog signal(s). The signal(s) may then be transmitted via communications channel 606. A noise source 608 may inject noise into the channel 606, thus obfuscating the transmitted signal(s). A receiver 610 may receive the analog signal(s) and convert the analog signal(s) into digital signals. The digital signals may be split into one or more channels or measurements 612. A decoder 614 may then decode the digital signals and provide digital bits 616 as output.
The input bits 602 and the output bits 616 may be compared to derive an error 618. The error 618 may then be used to train a neural network. For example, a transmitter and receiver pulse shape 620, 622 may be modelled by a neural network with unknown weights. The neural network may be initially trained in a supervised manner by minimizing an error function (e.g., error 618) between the transmitted bits 602 and the received bits 616. The system can either be trained using the real hardware and/or software operating in a real propagation channel 606, or leveraged on a simulated channel to accelerate the initial training. It is to be noted that the adaptive pulse shaping described with respect to the communications system 600 may be included in addition to or alternative to any other communications system described herein. By providing for in situ machine learning for adaptive pulse shaping, the techniques described herein may result in more optimal field communications in noisy channels, including subsea channels.
In the GAN embodiment of the telemetry system 650 illustrated in
As an alternative to or in addition to traditional design, the embodiments disclosed herein, such as the communications system 700, may use autoencoders techniques (e.g., autoencoder neural networks) for achieving an end-to-end leaning of the telecommunication channel. In the depicted embodiment, digital bits 720 may be used as input into an encoder 704, the bits may be converted into analog signals to be transmitted (block 706) via a channel 708. The channel 708 may have noise injected by noise sources 710, obfuscating the transmitted signals. A sensing and analog to digital block 712 may then receive the analog signals and transform the received signals into digital signals. The digital signals may be split into one or more channels or measurements 714, which may then be decoded via decoder 716 into digital bits 718.
The architecture embodiment of
Adaptive coupling of underwater navigation and mission-specific acoustic telemetry may also be used. For example, an outer-layer of automation executed above the underwater telemetry layer would under permissible circumstances trigger adaptive path and task planning to maximize the discovery or duration of an autonomous underwater vehicle (AUV) occupation of a region favorable to up-linking robustly inspection/surveying frames that would otherwise be unachievable along the normal path of the AUV. One such example, could be periodic transmission of inspection video/lidar images during a close-up inspection of a production equipment (pumps operating in gas-liquid flow regime) that generates significant acoustic noise, by virtue of managing reasonably short trips between the equipment and a favorable transmission zone. The tradeoff between completion of the close-up inspection and in-process uplinking could be learnt by reinforcement learning.
Cloud reinforcement learning using streaming data from multiple field locations may also be provided. In traditional reinforcement learning, the underlying model is typically learned offline using example field or synthetic data. During field operations, the learned model is shared with multiple agents (i.e. field locations) and is used for inference of parameters as discussed in other sections of this memo. However, in a setup with multiple agents, each agent is unaware of the data at other field locations, and the inference model is generally fixed for the duration of the job. To utilize real-time data from multiple field locations, the techniques described herein may use data that is streamed in real-time to a centralized server (i.e. the cloud). In the server, new samples are used to improve the inference model for edge cases and in terms of the overall reliability. The updated inference model is then periodically shared with all the field locations.
Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. Furthermore, any of the features shown and/or described with respect to
This application claims priority to and the benefit of U.S. Provisional Application No. 62/847,789, entitled “MACHINE LEARNING TECHNICS WITH SYSTEM IN THE LOOP FOR OIL & GAS TELEMETRY SYSTEMS,” filed May 14, 2019, which is hereby incorporated by reference in its entirety for all purposes.
Filing Document | Filing Date | Country | Kind |
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PCT/US2020/042010 | 7/14/2020 | WO | 00 |
Number | Date | Country | |
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62847789 | May 2019 | US |