Patent Grant
12180815
This disclosure generally relates to identifying hydrogen sweet spots in subsurface formations.
Molecular hydrogen (H2) is an energy-rich gas and clean fuel that produces only heat and water when combusted. H2 can be produced from gasification of coal, steam reforming of natural gas (mainly methane), and electrolysis of water.
Natural H2 can be generated and produced from subsurface formations. Surface gas survey, mud gas logging, crushed rock samples, downhole and wellhead fluid sampling can detect H2 in various environments with relatively enriched H2 (e.g., H2>6% mol) in some geological settings such as mid-ocean ridges, serpentinites, Precambrian basement, and volcanic/magmatic hydrothermal systems.
Natural H2 in a subsurface formation can be generated from various sources, for example, reduction of water during the oxidation of iron (Fe) minerals (e.g., serpentinization), radiolysis of water due to radioactive decay of uranium, thorium, or potassium, degassing of magma and deep-seated hydrogen from the core and mantle, and biogenic/thermogenic decomposition of organic matter.
This disclosure describes an approach to identifying hydrogen sweet spots (e.g., locations of H2 rich source rock, productive zones) in a subsurface formation. Laboratory pyrolysis experiments can be performed to determine an H2 generation potential of hydrocarbon source rock from the subsurface formation (e.g., a coal/organic-rich shale). Natural H2 can be effectively generated from thermally mature source rock when the source rock has passed peak methane production. The experimental data can be used to determine natural H2 potential in the subsurface formation through kinetic modeling and source rock evaluation. Using the generated data, the sweet spots for natural hydrogen generation can be identified.
Rock samples can be obtained from the subsurface formation. Pyrolysis of the rock samples can be performed to determine amounts of H2 and hydrocarbons that can be generated in the rock samples. Kinetic parameters can be determined based on the pyrolysis data to describe the generation rates of products. The generation of H2 and hydrocarbons in the subsurface formation can be simulated based on the kinetic parameters and the thermal history of the formation. The temperature range and thermal maturity of H2 and hydrocarbon generation can be determined in the simulation. Total organic content (TOC) and thermal maturity data can be measured for the rock samples. Hydrogen sweet spots can be identified in the subsurface formation based on the predicted target maturity data, TOC, and the measured rock sample maturity data.
Implementations of the systems and methods of this disclosure can provide various technical benefits. This approach links laboratory measurements of H2 generation from source rock samples to geologically measurable parameters (e.g., thermal maturity, depth) that can be used to locate the sweet spot in the subsurface formation. The hydrogen sweet spots identified by this approach can be targeted for natural H2 production with reduced cost and carbon footprint as compared with conventional H2 production (e.g., gasification of coal, steam reforming of natural gas, etc.). More natural H2 may be discovered in the well-sealed charged by the H2 generated in the source rock formation during the geological history. This approach can evaluate the total resource potential of H2. A resource potential parameter can be used to map the prospect of natural H2 accumulated in a subsurface formation and reduce risks of H2 exploration in regions with the access to the source rock.
The details of one or more implementations of these systems and methods are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of these systems and methods will be apparent from the description and drawings, and from the claims.
Like reference symbols in the various drawings indicate like elements.
This disclosure describes an approach to identifying hydrogen sweet spots in a subsurface formation. A hydrogen sweet spot can be a location in the subsurface formation that has reached a thermal maturity to produce natural hydrogen gas (H2). Rock samples can be obtained from the subsurface formation (e.g., an organic rich shale or coal formation). Pyrolysis of the rock samples can be performed to determine an amount of H2 that can be generated in the rock samples as compared to the conventional determination of hydrocarbon generation. Kinetic parameters can be determined based on the pyrolysis to describe the generation rates of the products. The generation of H2 and hydrocarbons in the subsurface formation can be simulated based on the kinetic parameters and the thermal history of the formation. The temperature range and thermal maturity of H2 and hydrocarbon generation can be predicted by the simulation. Total organic content (TOC) and thermal maturity data can be measured for the rock samples to determine a current total organic content and rock sample maturity of the subsurface formation. Hydrogen sweet spots can be identified in the subsurface formation based on the predicted maturity, the measured rock sample maturity data, and the total organic content.
The layers 14-22 in the subsurface formation 2 can be characterized using a wireline operation 24. A control truck 28 lowers a logging tool 32 (e.g., a sidewall coring tool) down the wellbore 10 on a wireline 36. As the logging tool 32 travels downhole, measurements of formations properties are recorded to generate a well log (e.g., resistivity logs, gamma ray logs, bulk density logs, porosity logs, acoustic logs). Using a wireline coring tool, core samples can be obtained in addition to obtaining well logs. A core sample is a usually cylindrical piece of the subsurface formation that is removed by a special drill and brought to the surface. Core samples can be used in pyrolysis experiments and source rock evaluations to determine the potential of H2 generated from the subsurface formation 2. Core samples can be taken from the sidewalls of a drilled well. When sidewall core samples are repeated along the length of the well, the properties measured from the core samples can be compared and correlated with well logging measurements. In the illustrated operation, the data can be recorded at the control truck 28 in real-time. Real-time data are recorded directly against measured cable depth. In some well-logging operations, the data is recorded at the logging tool 32 and downloaded later. In this approach, the downhole data and depth data are both recorded against time. The two data sets are then merged using the common time base to create an instrument response versus depth log.
In the wireline operation 24, the well logging and core sample collection is performed on a wellbore 10 that has already been drilled. In some operations, well logging and rock sample collection is performed while drilling the well using, for example, logging while drilling techniques and collecting drilling cuttings. In these techniques, the logging and core sample tools are integrated into the drill string and the measurements are made in real-time, during drilling rather than using sensors lowered into a well after drilling.
Rock samples are obtained from the subsurface formation (step 102). For example, rock samples are obtained from an organic-rich shale or coal subsurface formation in an area of interest. Rock samples can include core samples, sidewall core samples, washed drilling cuttings, and/or preserved outcrop samples.
Pyrolysis of the rock samples is performed to determine amounts of H2 and/or hydrocarbons that can be generated from the rock samples (step 104). Performing pyrolysis includes performing laboratory experiments to simulate hydrocarbon (e.g., gas and oil) and non-hydrocarbon (e.g., CO2, H2) generation from the kerogen of the source rock (e.g., shale/coal). The pyrolysis experiment can be done in an open system (e.g., pyrolysis gas chromatography) or a closed system (e.g., gold-tube pyrolysis) with different heating rates to reach the end of the generation of hydrocarbons and H2 for the rock samples. In open system pyrolysis, the open system expels products of the rock samples and leaves residual kerogen for cracking with increased temperature. In closed system pyrolysis, the closed system retains products produced from the rock samples in the system and keeps kerogen for cracking with secondary cracking of the produced products at higher temperature. The closed system pyrolysis retains and reacts H2 produced during the pyrolysis experiments whereas the open system releases the H2 as it is produced.
The quantity of H2 generated from an open system can be comparable to (or even more than) methane yield. In general, an open system can generate more H2 than a closed system due to, for example, the immediate escape of H2 in the open system, while most of the H2 generated in the closed system can be consumed, for example, in saturating hydrocarbon radicals formed in the cracking of kerogen or bitumen. In geological reality, full open source rock systems can be rare. Source rock in the subsurface formation can be on a spectrum between a semi-open and closed system due to, for example, low permeability and/or thickness of shale. H2 generation in an open pyrolysis system can represent a maximum potential of H2 generated in a hydrocarbon source rock. H2 generation in a closed pyrolysis system can be a conservative estimation of H2 potential in the hydrocarbon source rock.
Produced gas and oil can be collected from the pyrolysis experiment for quantification and compositional analysis. For example, oil, oil fractions, and gas components can be collected and quantified. Quantification can include for example, weighing, liquid chromatography, and gas chromatography. Procedures of the experiments and method for analysis are described in Behar, F., et al. “Thermal cracking of kerogen in open and closed systems: determination of kinetic parameters and stoichiometric coefficients for oil and gas generation,” Organic Geochemistry, 26(5-6), 321-339, which is incorporated by reference herein in its entirety. Pyrolysis experiments to measure H2 generation can be run for longer times and at higher temperatures than conventional pyrolysis experiments for determining hydrocarbon production. The H2 generation pyrolysis experiments can be run until no additional gas is generated from the kerogen in the rock sample.
Returning to
k=Ae−Ea/RT Eq. 1
where k is the reaction rate describing the change in molar mass of the reactant with respect to time; A is the frequency (pre-exponential) factor describing the number of potential elementary reactions per unit time; Ea is the activation energy (e.g., the energy barrier that must be exceeded in order for a reaction to occur); R is the gas constant equal to 8.31447 Ws/mol/K; Tis the reaction temperature (in Kelvin, K); and e is the base of the natural logarithm approximately equal to 2.718.
The Arrhenius equation theoretically determines the rate (k) of the transformation of kerogen to hydrocarbon and non-hydrocarbon (including H2) as a response to temperature (T) increase during the burial history (t) of the source rock. The kinetic parameters, activation energy (Ea) and frequency factor (A) can be inputs for a source rock in basin modeling to quantify generation, retention and expulsion of petroleum and to determine the timing of these processes. There are, for example, three types of kinetics for kerogen conversion with different details in products: bulk kinetics which converts kerogen into hydrocarbon; oil and gas kinetics which converts kerogen to oil and gas; and compositional kinetics which converts kerogen to multiple components (see, e.g., table 200).
The pyrolysis data are processed, for example, by a data processing system using kinetics analysis software or manual regression, to determine the kinetic parameters Ea and A. A discrete distribution of Ea and a common A can be determined for each product produced during pyrolysis.
Returning to
H2 gas can be generated by processes such as aromatization, annulation, or char gasification during kerogen maturation. These processes require high temperatures which occur in mature source rock in the geological history. H2 can be generated during the kerogen maturation as well as consumed in hydrocarbon generation. The aromatization and condensation of kerogen structures liberates H2 for the reduction of alkyl chains cleaved from kerogen at C—O and C—C bonds. Ring-opening reactions require the addition of H2 to yield methane and other hydrocarbon gases. In the closed system, there would be a competitive consumption of the H2 residing in kerogen by the formation of methane over H2.
A threshold for effective H2 generation can be the generation rate of H2 exceeding C2 (ethane). Beyond this threshold, a relatively high temperature/maturity can promote H2 generation reactions in company with gradually exhausted free radical reactions for the formation of hydrocarbon gases. When the generation rate of H2 exceeds methane, the formation of H2 can capture the residual hydrogen in the kerogen. The dominant H2 generation, with less and less dilution by methane generation as temperature/maturity increase, can accumulate in-situ in the subsurface formation to form H2 sweet spots in the source rock reservoir (e.g., organic-rich shale or coal).
Additionally, there is a pragmatic consideration for the generation rate of H2 over methane as a control for H2 richness. For example, in a global dataset, shale gas exploration and production targeted on hydrocarbon gas dominated by methane. The occurrence of methane can be unfavorable for the formation of H2. In some examples, an organic-rich shale with active hydrocarbon generation or a petroleum reservoir with active hydrocarbon cracking can be considered a sink of H2. In samples from a formation with dominant methane production, few samples show traces of H2, and those few samples include small amounts of H2.
In some implementations, the temperature in a heating process (e.g., 2°/h, 2° C./Ma) can be converted to a commonly used proxy of thermal maturity, vitrinite reflectance (Ro). For example, an Easy % Ro model can be used to convert the extent of heating to Ro (Sweeney and Burnham, 1990, “Evaluation of a simple model of vitrinite reflectance based on chemical kinetics.” AAPG bulletin, 74(10), 1559-1570). A regression line based on the Ro calculation describes the relationship between the temperature and the thermal maturity (Ro) under a certain heating rate. Ro values can be predicted for effective H2 generation, dominate H2 generation and peak H2 generation to define the target maturity for H2 richness. In some implementations, other proxies for thermal maturity can be used.
Returning to
The H2 resource potential can be evaluated based on the peak H2 generation. An H2 resource potential parameter (mg H2/g TOC) can be determined based on the simulation. For example, the peak H2 generation rate 510 is 0.1 mg/g TOC/° C. (1.1125 ml/g TOC/° C. at standard temperature and pressure (STP)) for the sample in the kinetic modeling. Integrating the area under the generation rate curve within the target temperature range for H2 generation can provide an estimation of the H2 resource potential (mg H2/g TOC) in the target zone of the subsurface formation. The integration of the whole H2 generation window (170-345° C.) represents the total H2 resource potential (mg H2/g TOC) of the subsurface formation at that location. The resource for an area of interest in the subsurface formation can be calculated by a volumetric equation:
H2 Resource=Resource Potential*Average TOC*Thickness*Area Eq. 2
An open system pyrolysis can generate much more H2 than a closed system as discussed earlier. Therefore, the numbers of peak generation rate and resource potential obtained and simulated in a closed system can represent a conservative estimation for H2 resource potential in the subsurface formation.
H2 sweet spots are identified in the subsurface formation based on the predicted target maturity data, the TOC, and the measured rock sample maturity data (step 112). H2 sweet spots correspond to the locations in the subsurface formation that have the identified target maturity.
In some implementations, one or more wells can be drilled in the subsurface formation to access the H2 in the identified sweet spots (step 114). For example, one or more wells can be drilled in the subsurface formation at locations near an exploration well that would be expected to have similar thermal maturity and TOC. The wells can be drilled to a depth at which the identified H2 sweet spot can be accessed. In some implementations, a horizontal well can be drilled within the sweet spot sot produce H2 from the sweet spot. Cuttings and/or core samples taken from the one or more wells can be analyzed to measure the Ro value and validate the identified location of the H2 sweet spot in the subsurface formation.
In some implementations, a data processing system controls drilling equipment to drill the one or more wells in the subsurface based on the identified H2 sweet spots. For example, the data processing system can control the depth of the well or the direction of the well to access the identified H2 sweet spot. In some implementations, the data processing system can control production equipment to produce the H2 from the H2 sweet spots.
Implementations of method 100 can benefit from systematic sampling of the subsurface formation in areas of interest. For example, taking systematic samples from organic-rich shale or coal crossing thermal maturities in the area of interest. High resolution sampling (e.g., 3 ft per one sample) in the target formation can better define the depth of the H2 sweet spot. Selecting the most immature sample and the most mature sample for pyrolysis experiment and kinetic modeling can provide upper and lower bounds on the H2 resource potential. Repeating steps 110-112 for multiple wells in the subsurface formation with available source rock samples and correlating the wells with one another can generate a cross section or 3D model of the H2 potential in the subsurface formation and map the location of sweet spots in the area of interest.
Examples of field operations 710 include forming/drilling a wellbore, hydraulic fracturing, producing through the wellbore, injecting fluids (such as water) through the wellbore, to name a few. In some implementations, methods of the present disclosure can trigger or control the field operations 710. For example, the methods of the present disclosure can generate data from hardware/software including sensors and physical data gathering equipment (e.g., seismic sensors, well logging tools, flow meters, and temperature and pressure sensors). The methods of the present disclosure can include transmitting the data from the hardware/software to the field operations 710 and responsively triggering the field operations 710 including, for example, generating plans and signals that provide feedback to and control physical components of the field operations 710. Alternatively, or in addition, the field operations 710 can trigger the methods of the present disclosure. For example, implementing physical components (including, for example, hardware, such as sensors) deployed in the field operations 710 can generate plans and signals that can be provided as input or feedback (or both) to the methods of the present disclosure.
Examples of computational operations 712 include one or more computer systems 720 that include one or more processors and computer-readable media (e.g., non-transitory computer-readable media) operatively coupled to the one or more processors to execute computer operations to perform the methods of the present disclosure. The computational operations 712 can be implemented using one or more databases 718, which store data received from the field operations 710 and/or generated internally within the computational operations 712 (e.g., by implementing the methods of the present disclosure) or both. For example, the one or more computer systems 720 process inputs from the field operations 710 to assess conditions in the physical world, the outputs of which are stored in the databases 718. For example, seismic sensors of the field operations 710 can be used to perform a seismic survey to map subterranean features, such as facies and faults. In performing a seismic survey, seismic sources (e.g., seismic vibrators or explosions) generate seismic waves that propagate in the earth and seismic receivers (e.g., geophones) measure reflections generated as the seismic waves interact with boundaries between layers of a subsurface formation. The source and received signals are provided to the computational operations 712 where they are stored in the databases 718 and analyzed by the one or more computer systems 720.
In some implementations, one or more outputs 722 generated by the one or more computer systems 720 can be provided as feedback/input to the field operations 710 (either as direct input or stored in the databases 718). The field operations 710 can use the feedback/input to control physical components used to perform the field operations 710 in the real world.
For example, the computational operations 712 can process the seismic data to generate three-dimensional (3D) maps of the subsurface formation. The computational operations 712 can use these 3D maps to provide plans for locating and drilling exploratory wells. In some operations, the exploratory wells are drilled using logging-while-drilling (LWD) techniques which incorporate logging tools into the drill string. LWD techniques can enable the computational operations 712 to process new information about the formation and control the drilling to adjust to the observed conditions in real-time.
The one or more computer systems 720 can update the 3D maps of the subsurface formation as information from one exploration well is received and the computational operations 712 can adjust the location of the next exploration well based on the updated 3D maps. Similarly, the data received from production operations can be used by the computational operations 712 to control components of the production operations. For example, production well and pipeline data can be analyzed to predict slugging in pipelines leading to a refinery and the computational operations 712 can control machine operated valves upstream of the refinery to reduce the likelihood of plant disruptions that run the risk of taking the plant offline.
In some implementations of the computational operations 712, customized user interfaces can present intermediate or final results of the above-described processes to a user. Information can be presented in one or more textual, tabular, or graphical formats, such as through a dashboard. The information can be presented at one or more on-site locations (such as at an oil well or other facility), on the Internet (such as on a webpage), on a mobile application (or app), or at a central processing facility.
The presented information can include feedback, such as changes in parameters or processing inputs, that the user can select to improve a production environment, such as in the exploration, production, and/or testing of petrochemical processes or facilities. For example, the feedback can include parameters that, when selected by the user, can cause a change to, or an improvement in, drilling parameters (including drill bit speed and direction) or overall production of a gas or oil well. The feedback, when implemented by the user, can improve the speed and accuracy of calculations, streamline processes, improve models, and solve problems related to efficiency, performance, safety, reliability, costs, downtime, and the need for human interaction.
In some implementations, the feedback can be implemented in real-time, such as to provide an immediate or near-immediate change in operations or in a model. The term real-time (or similar terms as understood by one of ordinary skill in the art) means that an action and a response are temporally proximate such that an individual perceives the action and the response occurring substantially simultaneously. For example, the time difference for a response to display (or for an initiation of a display) of data following the individual's action to access the data can be less than 1 millisecond (ms), less than 1 second (s), or less than 5 s. While the requested data need not be displayed (or initiated for display) instantaneously, it is displayed (or initiated for display) without any intentional delay, taking into account processing limitations of a described computing system and time required to, for example, gather, accurately measure, analyze, process, store, or transmit the data.
Events can include readings or measurements captured by downhole equipment such as sensors, pumps, bottom hole assemblies, or other equipment. The readings or measurements can be analyzed at the surface, such as by using applications that can include modeling applications and machine learning. The analysis can be used to generate changes to settings of downhole equipment, such as drilling equipment. In some implementations, values of parameters or other variables that are determined can be used automatically (such as through using rules) to implement changes in oil or gas well exploration, production/drilling, or testing. For example, outputs of the present disclosure can be used as inputs to other equipment and/or systems at a facility. This can be especially useful for systems or various pieces of equipment that are located several meters or several miles apart or are located in different countries or other jurisdictions.
The computer 802 can serve in a role as a client, a network component, a server, a database, a persistency, or components of a computer system for performing the subject matter described in the present disclosure. The illustrated computer 802 is communicably coupled with a network 830. In some implementations, one or more components of the computer 802 can be configured to operate within different environments, including cloud-computing-based environments, local environments, global environments, and combinations of environments.
At a high level, the computer 802 is an electronic computing device operable to receive, transmit, process, store, and manage data and information associated with the described subject matter. According to some implementations, the computer 802 can also include, or be communicably coupled with, an application server, an email server, a web server, a caching server, a streaming data server, or a combination of servers.
The computer 802 can receive requests over network 830 from a client application (for example, executing on another computer 802). The computer 802 can respond to the received requests by processing the received requests using software applications. Requests can also be sent to the computer 802 from internal users (for example, from a command console), external (or third) parties, automated applications, entities, individuals, systems, and computers.
Each of the components of the computer 802 can communicate using a system bus 803. In some implementations, any or all of the components of the computer 802, including hardware or software components, can interface with each other or the interface 804 (or a combination of both), over the system bus 803. Interfaces can use an application programming interface (API) 812, a service layer 813, or a combination of the API 812 and service layer 813. The API 812 can include specifications for routines, data structures, and object classes. The API 812 can be either computer-language independent or dependent. The API 812 can refer to a complete interface, a single function, or a set of APIs.
The service layer 813 can provide software services to the computer 802 and other components (whether illustrated or not) that are communicably coupled to the computer 802. The functionality of the computer 802 can be accessible for all service consumers using this service layer. Software services, such as those provided by the service layer 813, can provide reusable, defined functionalities through a defined interface. For example, the interface can be software written in JAVA, C++, or a language providing data in extensible markup language (XML) format. While illustrated as an integrated component of the computer 802, in alternative implementations, the API 812 or the service layer 813 can be stand-alone components in relation to other components of the computer 802 and other components communicably coupled to the computer 802. Moreover, any or all parts of the API 812 or the service layer 813 can be implemented as child or sub-modules of another software module, enterprise application, or hardware module without departing from the scope of the present disclosure.
The computer 802 includes an interface 804. Although illustrated as a single interface 804 in
The computer 802 includes a processor 805. Although illustrated as a single processor 805 in
The computer 802 also includes a database 806 that can hold data for the computer 802 and other components connected to the network 830 (whether illustrated or not). For example, database 806 can hold data 816 (e.g., resistivity data). For example, database 806 can be an in-memory, conventional, or a database storing data consistent with the present disclosure. In some implementations, database 806 can be a combination of two or more different database types (for example, hybrid in-memory and conventional databases) according to particular needs, desires, or particular implementations of the computer 802 and the described functionality. Although illustrated as a single database 806 in
The computer 802 also includes a memory 807 that can hold data for the computer 802 or a combination of components connected to the network 830 (whether illustrated or not). Memory 807 can store any data consistent with the present disclosure. In some implementations, memory 807 can be a combination of two or more different types of memory (for example, a combination of semiconductor and magnetic storage) according to particular needs, desires, or particular implementations of the computer 802 and the described functionality. Although illustrated as a single memory 807 in
The application 808 can be an algorithmic software engine providing functionality according to particular needs, desires, or particular implementations of the computer 802 and the described functionality. For example, application 808 can serve as one or more components, modules, or applications. Further, although illustrated as a single application 808, the application 808 can be implemented as multiple applications 808 on the computer 802. In addition, although illustrated as internal to the computer 802, in alternative implementations, the application 808 can be external to the computer 802.
The computer 802 can also include a power supply 814. The power supply 814 can include a rechargeable or non-rechargeable battery that can be configured to be either user- or non-user-replaceable. In some implementations, the power supply 814 can include power-conversion and management circuits, including recharging, standby, and power management functionalities. In some implementations, the power-supply 814 can include a power plug to allow the computer 802 to be plugged into a wall socket or a power source to, for example, power the computer 802 or recharge a rechargeable battery.
There can be any number of computers 802 associated with, or external to, a computer system containing computer 802, with each computer 802 communicating over network 830. Further, the terms “client,” “user,” and other appropriate terminology can be used interchangeably, as appropriate, without departing from the scope of the present disclosure. Moreover, the present disclosure contemplates that many users can use one computer 802 and one user can use multiple computers 802.
Implementations of the subject matter and the functional operations described in this specification can be implemented in digital electronic circuitry, in tangibly embodied computer software or firmware, in computer hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. Software implementations of the described subject matter can be implemented as one or more computer programs. Each computer program can include one or more modules of computer program instructions encoded on a tangible, non transitory, computer-readable computer-storage medium for execution by, or to control the operation of, data processing apparatus. Alternatively, or additionally, the program instructions can be encoded in/on an artificially generated propagated signal. The example, the signal can be a machine-generated electrical, optical, or electromagnetic signal that is generated to encode information for transmission to suitable receiver apparatus for execution by a data processing apparatus. The computer-storage medium can be a machine-readable storage device, a machine-readable storage substrate, a random or serial access memory device, or a combination of computer-storage mediums.
The terms “data processing apparatus,” “computer,” and “electronic computer device” (or equivalent as understood by one of ordinary skill in the art) refer to data processing hardware. For example, a data processing apparatus can encompass all kinds of apparatus, devices, and machines for processing data, including by way of example, a programmable processor, a computer, or multiple processors or computers. The apparatus can also include special purpose logic circuitry including, for example, a central processing unit (CPU), a field programmable gate array (FPGA), or an application specific integrated circuit (ASIC). In some implementations, the data processing apparatus or special purpose logic circuitry (or a combination of the data processing apparatus or special purpose logic circuitry) can be hardware- or software-based (or a combination of both hardware- and software-based). The apparatus can optionally include code that creates an execution environment for computer programs, for example, code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of execution environments. The present disclosure contemplates the use of data processing apparatuses with or without conventional operating systems, for example LINUX, UNIX, WINDOWS, MAC OS, ANDROID, or IOS.
The methods, processes, or logic flows described in this specification can be performed by one or more programmable computers executing one or more computer programs to perform functions by operating on input data and generating output. The methods, processes, or logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, for example, a CPU, an FPGA, or an ASIC.
Computer readable media (transitory or non-transitory, as appropriate) suitable for storing computer program instructions and data can include all forms of permanent/non-permanent and volatile/non-volatile memory, media, and memory devices. Computer readable media can include, for example, semiconductor memory devices such as random access memory (RAM), read only memory (ROM), phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), and flash memory devices. Computer readable media can also include, for example, magnetic devices such as tape, cartridges, cassettes, and internal/removable disks.
While this specification contains many specific implementation details, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features that may be specific to particular implementations. Certain features that are described in this specification in the context of separate implementations can also be implemented, in combination, in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations, separately, or in any suitable sub-combination. Moreover, although previously described features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can, in some cases, be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.
Particular implementations of the subject matter have been described. Other implementations, alterations, and permutations of the described implementations are within the scope of the following claims as will be apparent to those skilled in the art. While operations are depicted in the drawings or claims in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed (some operations may be considered optional), to achieve desirable results. In certain circumstances, multitasking or parallel processing (or a combination of multitasking and parallel processing) may be advantageous and performed as deemed appropriate.
Moreover, the separation or integration of various system modules and components in the previously described implementations should not be understood as requiring such separation or integration in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.
Accordingly, the previously described example implementations do not define or constrain the present disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of the present disclosure.
Furthermore, any claimed implementation is considered to be applicable to at least a computer-implemented method; a non-transitory, computer-readable medium storing computer-readable instructions to perform the computer-implemented method; and a computer system comprising a computer memory interoperably coupled with a hardware processor configured to perform the computer-implemented method or the instructions stored on the non-transitory, computer-readable medium.
A number of implementations of these systems and methods have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of this disclosure. Accordingly, other implementations are within the scope of the following claims.
In an example implementation, a method for identifying natural hydrogen sweet spots in a subsurface formation includes obtaining rock samples from the subsurface formation; performing pyrolysis of the rock samples to determine an amount of hydrogen generated in the rock samples; determining kinetic parameters based on the performed pyrolysis and a thermal history of the subsurface formation; simulating hydrogen generation in the subsurface formation based on the determined kinetic parameters and the thermal history to predict target maturity data for hydrogen richness in the subsurface formation; measuring total organic content and rock sample maturity data for the rock samples; and identifying hydrogen sweet spots in the subsurface formation based on the target maturity data, the total organic content, and the measured rock sample maturity data.
An aspect combinable with the example implementation includes in response to identifying hydrogen sweet spots, drilling one or more wells in the subsurface formation to access the hydrogen sweet spots.
Another aspect combinable with any of the previous aspects includes controlling production equipment to produce hydrogen from the one or more wells.
Another aspect combinable with any of the previous aspects includes measuring thermal maturity of cuttings or core samples taken from the one or more wells to validate the identified hydrogen sweet spots.
In another aspect combinable with any of the previous aspects, the subsurface formation includes an organic rich shale formation or a coal formation.
Another aspect combinable with any of the previous aspects includes converting the target maturity data to temperature and depth data.
In another aspect combinable with any of the previous aspects, simulating the hydrogen generation includes applying a geological heating rate or thermal history to a basin model including the kinetic parameters to provide generation rate data, timing data, and yield data for oil, hydrocarbon gases, and hydrogen in the subsurface formation.
In another aspect combinable with any of the previous aspects, identifying hydrogen sweet spots includes identifying regions of the subsurface formation having a higher generation rate of hydrogen than generation rates of ethane and methane.
In another aspect combinable with any of the previous aspects, simulating hydrogen generation includes determining thermal maturity data for the subsurface formation, and the target maturity data includes vitrinite reflectance data for effective hydrogen generation, dominant hydrogen generation, and peak hydrogen generation.
Another aspect combinable with any of the previous aspects includes determining a hydrogen resource potential in the subsurface formation based on the simulated hydrogen generation, the total organic content, and a volumetric estimation of the identified hydrogen sweet spots in the subsurface formation.
In another example implementation, a system for identifying natural hydrogen sweet spots in a subsurface formation includes at least one processor; and a memory storing instructions that, when executed by the at least one processor, cause the at least one processor to perform operations including performing pyrolysis of the rock samples to determine an amount of hydrogen generated in the rock samples; determining kinetic parameters based on the performed pyrolysis and a thermal history of the subsurface formation; simulating hydrogen generation in the subsurface formation based on the determined kinetic parameters to predict target maturity data for hydrogen richness in the subsurface formation; measuring total organic content and rock sample maturity data for the rock samples; and identifying hydrogen sweet spots in the subsurface formation based on the target maturity data, the total organic content, and the measured rock sample maturity data.
In an aspect combinable with the example implementation, the operations include in response to identifying hydrogen sweet spots, drilling one or more wells in the subsurface formation to access the hydrogen sweet spots.
In another aspect combinable with any of the previous aspects, the operations include controlling production equipment to produce hydrogen from the one or more wells.
In another aspect combinable with any of the previous aspects, the operations include measuring thermal maturity of cuttings or core samples taken from the one or more wells to validate the identified hydrogen sweet spots.
In another aspect combinable with any of the previous aspects, the subsurface formation includes an organic rich shale formation or a coal formation.
In another aspect combinable with any of the previous aspects, the operations include converting the target maturity data to temperature and depth data.
In another aspect combinable with any of the previous aspects, simulating the hydrogen generation includes applying a geological heating rate or thermal history to a basin model including the kinetic parameters to provide generation rate data, timing data, and yield data for oil, hydrocarbon gases, and hydrogen in the subsurface formation.
In another aspect combinable with any of the previous aspects, identifying hydrogen sweet spots includes identifying regions of the subsurface formation having a higher generation rate of hydrogen than generation rates of ethane and methane.
In another aspect combinable with any of the previous aspects, simulating hydrogen generation includes determining thermal maturity data for the subsurface formation, and the target maturity data includes vitrinite reflectance data for effective hydrogen generation, dominant hydrogen generation, and peak hydrogen generation.
In another aspect combinable with any of the previous aspects, the operations include determining a hydrogen resource potential in the subsurface formation based on the simulated hydrogen generation, the total organic content, and a volumetric estimation of the identified hydrogen sweet spots in the subsurface formation.
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