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- Volume 40, Issue 10, 2022
First Break - Volume 40, Issue 10, 2022
Volume 40, Issue 10, 2022
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Attempts at seismic characterization of a deepwater turbidite channel in Taranaki Basin, New Zealand
Authors Satinder Chopra, Ritesh Kumar Sharma, Kurt J. Marfurt, Heather Bedle and Sumit VermaAbstractThe deepwater Taranaki Basin located off the northwest coast of New Zealand has considerable potential for big hydrocarbon discoveries, though the country has decided to stop all new offshore exploration to address climate change. The challenge is to determine the presence, distribution, and quality of turbidite reservoirs in the giant Late Miocene channel complex that runs through the deepwater basin. We use seismic attributes and a seismic geomorphology driven workflow that maps individual architectural elements of the channel system and allows us to predict facies that have the potential to be good reservoirs. Data conditioning to balance the spectrum provides significant improvement in not only vertical but also lateral resolution of the channel complex. We show that attributes computed from frequency-balanced data better delineate the finer features in the channel complex. Some attribute combinations can be readily combined through multi-attribute visualization to better map the reservoir architectural elements. Other attributes can be effectively combined for seismic facies classification using unsupervised machine learning application including self-organizing mapping (SOM) and generative topographic mapping (GTM). We find that improving the data bandwidth through frequency balancing improves not only the resolution of attributes by themselves, but also when combined using machine learning.
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Accelerating Results in Carbon Storage Studies Using an Integrated and Automated Approach
More LessAbstractGeological storage of carbon dioxide (CO2) is considered an enabler of different business models aligned with decarbonization of the energy market. Partnerships are forming worldwide to develop large-scale carbon capture, utilization and storage (CCUS) projects: 2021 was a record year for project pipeline growth for these types of projects. This growth will result in an increasing need for subsurface technologies that can unlock fast time-to-results throughout all the steps of the project, from site selection to storage monitoring.
At an early stage of a carbon storage project, a thorough verification of the technical and economic viability of the project is critical. The high degree of geological uncertainties in the case of storage in under-explored saline aquifers can make this step challenging. As the project progresses, fast assimilation of monitoring data to prove conformance and update predictions of the storage complex performance is key.
An advanced technology from AspenTech can serve as a catalyst for efficient carbon storage studies. It tightly integrates static and dynamic domains and offers the propagation of uncertainties, from seismic characterization through to geological modelling and simulation. Using results from a large set of models increases predictability of the subsurface and enables more efficient analysis of uncertainty in predicted storage capacity and containment. This fully automated workflow can be run at will with new data, drastically reducing the time needed by carbon storage teams to update the model and the predictions as monitoring data is acquired.
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Acquiring Sustainable, Efficient High-Resolution Seismic Data for Geothermal Exploration in an Urban Environment
Authors Nick Tranter, Richard de Kunder, Ben Turner and Guy DrijkoningenAbstractThe overall conditions under which geophysical data are being acquired have changed over the past five years due to the global economy combined with an increased emphasis on low environmental impact sustainability and safety. For land seismic acquisition, minimizing land disturbance, reducing CO2 emissions and increasing crew safety are key motivators to use innovations that drastically change conventional land seismic acquisition methods. One of the sources proven to do this is the eVibe developed by Seismic Mechatronics B V. They were recently contracted to undertake an urban seismic program utilizing their proprietary eVibe source in combination with Stryde Nodes. The seismic survey was acquired in one of the largest cities in the Netherlands, without the need for permits. Being able to minimize environmental impact, to reach a high safety standard and to acquire high-quality data in a noisy urban environment with the used technology made this project a success. This paper compares the results achieved by the Storm10 eVibe in combination with Stryde nodes to results previously obtained by an explosive survey. We show that the results are technically superior, with the eVibe and the Stryde Nodes proving far better suited to acquiring seismic data within this challenging and restrictive urban environment.
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Integrated machine learning and physics-based workflows for rapid qualitative and quantitative insights on monitoring carbon capture and sequestration
Authors Khushboo Havelia, Surender Manral, Hilde Grude Borgos and Steve FreemanAbstractWith the onset of extensive development and focus on clean and sustainable sources of energy, our subsurface geoscience tools and technologies can be effectively repurposed and evolved to support the energy transition. These sustainable energy sources are easily replenishable and low carbon. Some of the emerging sectors are geothermal energy, carbon capture and sequestration (CCS), energy storage, offshore wind energy, sustainable battery-grade lithium extraction, and hydrogen production. These sectors can benefit immensely from economically viable geophysical tools that are available at our disposal to deliver better and faster business outcomes. In this paper we will discuss the integrated machine learning (ML) and physics-based workflows that can be used for enabling effective and rapid energy transition solutions. In our study we will focus on CCS subsurface monitoring workflows, but the same methods have been applied to many other energy transition areas (for example, offshore wind and geothermal energy).
The integrated workflows mentioned above were applied on the Sleipner gas field in the North Sea, where CCS operations have been ongoing since 1996. Rapid qualitative workflows like amplitude analysis and seismic blending were used to build an initial understanding of the carbon dioxide (CO2) plume and its spread. Geoscientist-driven ML-assisted horizon mapping facilitated rapid interpretation of structure across different time vintages. Then, advanced techniques like amplitude vs. offset (AVO) analysis and time-lapse seismic inversion were used for quantitative analysis. These analyses gave comprehensive information on CO2 spread in each subformation, as well as an estimate of the changing CO2 volume through time.
These workflows can be applied in CCS operations to successfully monitor CO2 in the subsurface and quickly detect and assess the risk of leaks.
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Natural Hydrogen: A New Source of Carbon-Free and Renewable Energy That Can Compete With Hydrocarbons
Authors Christophe Rigollet and Alain PrinzhoferAbstractEmanations of natural hydrogen are observed on the surface of the Earth at multiple points, on the five continents and on the mid-ocean ridges. When the geological conditions are favourable, this gas can accumulate at shallow depths and thus be of economic interest in contributing to the decarbonation of the energy mix.
The first deposit of natural hydrogen was accidentally discovered in 1987 in Mali and is currently in the industrial development phase. In the last two years, a dazzling multiplication of exploration projects dedicated to natural hydrogen have been launched and the first successes have been announced. At the same time, few countries have adapted their mining codes to facilitate permit submission.
The year has also been marked by the second H-Nat international congress, which brought together scientists and industrialists on the issue of exploring and producing natural hydrogen in the short term. At the same time the European EARTH2 club was founded on the initiative of 45−8 Energy, CVA and the Avenia cluster, to overcome competitive tensions and jointly promote underground solutions to the ‘hydrogen revolution’.
This article provides an inventory of knowledge of the hydrogen produced naturally by the Earth and presents exploratory guidelines.
The hydrogen currently on the market is of manufactured origin, but natural hydrogen can also be exploited from the subsoil
70 Mt of hydrogen are consumed each year worldwide, mainly for industrial purposes. This hydrogen, called ‘grey hydrogen’, is manufactured by steam reforming of hydrocarbons (78%) and coal (18%). ‘Green hydrogen’, produced by electrolysis of water, represents only 4% of this mix. However, hydrogen also exists in the subsoil, in its natural state (Prinzhofer and Deville, 2015), it is called ‘white hydrogen’ or ‘native hydrogen’.
- Steam reforming is a developed technology but emits a lot of CO2 (more than 10 kg of CO2 per kg of H2). Including CO2 capture and storage, the production cost is around $ 2–4/kg.
- Water electrolysis uses available but energy-intensive production processes. The cost of production from renewable electricity remains high, between 5 and 8 $/kg.
- Natural hydrogen is a resource in constant renewal. Its exploitation requires little energy, no fresh water and does not emit CO2. Production costs are estimated at less than 1 $/kg and decrease in a coproduction business model (geothermal energy, helium, high-value brines).
Natural hydrogen is therefore cheaper than manufactured hydrogen and does not emit CO2. It would therefore be an ideal complement to hydrogen produced by electrolysis in a carbon-free energy mix. Its lower cost than other renewable and carbon-free energy sources places it, in terms of competitiveness, in a favourable position to challenge fossil hydrocarbons. The small investments needed today to develop it, its possibly local and decentralized use, make it a paradigm changer for our energy future.
Even if the presence of natural hydrogen was highlighted in water or hydrocarbon drilling more than a century ago in France and Australia (Ward et al., 1933), the first drilling devoted to this exploration is much more recent. The first large-scale exploratory projects were carried out by the Hydroma company in Mali from 2008 in the Bourakebougou region, 20 years after the accidental discovery of the deposit (Prinzhofer et al., 2018). Today, small companies are focused on hydrogen exploration such as in the USA where NH2E carried out deep drilling in Nebraska in 2019 or Desert Mountain Energy which announced in February 2022 the discovery of a natural hydrogen field in Arizona. In Australia, Santos, after several exploration wells, announced in 2021 the completion of a first natural hydrogen producing well in the Amadeus basin. In Europe companies are also developing this type of activity, such as Hynat in Switzerland, 45−8 Energy and Engie in France or Helios in Spain.
To reduce costs, natural hydrogen can also be considered as a co-product of geothermal energy. But hydrogen can also be associated with other gases of economic interest such as methane, CO2 and more particularly helium. A coupled H2-He production for example, would make it possible to optimize this type of operation. This covalorization approach, which has been developed by 45-8 Energy since its creation, has now been widely disseminated in the scientific and industrial community.
In most countries, the mining code is not yet adapted to the regulation of hydrogen exploration and production, but updates are in progress
The mining codes were drafted and adopted when natural hydrogen was still unknown as a natural resource. It is therefore necessary to adapt it so that natural hydrogen can be classified in one of the categories explicitly mentioned by the mining code.
Several countries modified (or are modifying) their mining code to provide industrial initiatives with the necessary regulatory framework, such as Australia, Mali, Morocco, Congo, Ukraine, France and Germany.
Natural hydrogen finds its source in the subsoil, at depth, before migrating to the surface and finally dispersing in the atmosphere. However, this source-migration-accumulation-leakage system has elements that distinguish it from the oil system.
Natural hydrogen can be produced in the Earth’s crust from different processes. Some even propose a deeper origin in the mantle or the core of the earth which would have preserved primordial hydrogen (Larin et al., 1993).
The natural hydrogen produced in the Earth’s crust can be generated by the radiolysis of water due to natural radioactivity, or by the oxidation of ‘ferrous’ iron to ‘ferric’ iron reducing water into hydrogen. In the natural context, this last reaction, such as the serpentinization of mafic and ultramafic rocks, is particularly effective around 300°C in the presence of water, but it can also take place more slowly at lower temperatures, then at a shallower depth, as has been shown in the laboratory.
Natural hydrogen can also result from other processes such as pyritization (Arrouvel and Prinzhofer, 2021) and ammonium decomposition (Jacquemet, 2022), mechanical friction of silicates at faults, dark fermentation of matter organic matter, the bio-photolysis of water or the cracking of organic matter.
If we define the hydrogen system as the dynamic association source-migration-accumulation-loss, the comparison between the petroleum system is tempting. However, the differences are numerous. First of all, the depths that are at stake. The genesis of hydrogen may be deeper than that of hydrocarbons and the accumulations of hydrogen may, on the contrary, be shallower, as is the case in Mali. The main source of hydrocarbons is organic matter, while hydrogen is formed by mineral chemistry reactions, in rocks which may be sedimentary or plutonic. While for hydrocarbons it is necessary to have traps to capture the fluids, the accumulations of hydrogens can be perceived as more dynamic. Any change in rock properties that would help in slowing the gas on its migration path can promote transient accumulation on human timescales. Consequently, while the resource of a hydrocarbon deposit is measured in volume, the resource of a hydrogen deposit must integrate the notion of feeding flow.
From a temporal point of view, the petroleum system is a system that operates on the scale of geological time. Hydrocarbons are therefore considered non-renewable on a human scale. In comparison, the natural hydrogen accumulations are continuously fed by large flows and the hydrogen that reaches the surface oxidizes in the form of water, which makes this new renewable carbon-free energy resource part of the water cycle. Hydrogen fluxes are much larger, both in terms of their genesis and in terms of surface exudations.
The inventory of natural hydrogen emissions at the surface shows that the resource is widely distributed on all continents, in various geological contexts.
Natural hydrogen is present in the atmosphere but in very low concentrations, around 0.5 ppm. However, it is found in higher concentrations at point sources such as submarine or continental fumaroles, hot springs, ‘fairy circles’ or along fractures and faults. Many boreholes have also found hydrogen at varying depths, from a few metres to more than 1000 m (Guélard, 2016, Prinzhofer et al., 2019, Boreham et al., 2021 and Pélissier et al., 2021).
Surface emissions have been mapped globally and show a wide distribution (Prinzhofer and Deville, 2015, Zgonnik, 2020, see Figure 1). They appear along oceanic ridges, on obducted oceanic plates (ophiolites from Oman, New Caledonia, the Philippines, Turkey, etc.) or in mountain ranges (Pyrenees). They are also observed on the edges of graben (Rhine Graben and Rhine Ditch) and in Proterozoic cratons (Russia, USA, Brazil, Australia, Africa, etc.).
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Required Capabilities for Assessing Depleted and Deep Saline Reservoirs for Successful CCS Projects
Authors H.J. Kloosterman and A. KirchinSummaryDepleted and saline reservoir types are the main candidates to consider for any CCS-scenario. Both kinds of reservoir have fundamentally different risk profiles and degrees of uncertainty and each of them has a role to play in successful CO2 sequestration scenarios.
Depleted reservoirs provide a relatively rapid path to storage with significantly less uncertainty on containment and injectivity efficiency. However, the large number of well penetrations that reduce the performance uncertainty also increase the risk of potential leakage points.
In contrast, deep saline reservoirs will take longer to bring to project maturity but have by an order of magnitude more storage potential. Additionally, they will almost certainly support super-critical injection in dense phase making the project design much simpler to manage and monitor.
Successful long-term CO2 storage projects are likely to employ a combination of both types of reservoirs through a phased life-cycle where the use of a depleted reservoir enables early injection whilst an adjacent saline reservoir is brought ‘on stream’ later on.
The implementation of successful CO2 storage projects requires capabilities with strong adjacency to the oil and gas sector, supplemented with those specific to CO2 storage, requiring flexible and adaptable approaches to the upskilling of key staff.
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Green Technology to Help Calculate Subsurface Geothermal Zones and Temperatures Before Drilling
Authors G. Stove, O. Delgado, D. Limmer and L. LawrenceAbstractGeothermal energy is simply the natural heat that exists within our planet. The potential for harnessing electricity and heat from geothermal energy has long been recognised in Iceland, Hungary and New Zealand (Shere, 2013). Geothermal power has considerable potential for growth. The amount of heat within 10,000 m of the earth’s surface is estimated to contain 50,000 times more energy than all oil and gas resources worldwide (Shere, 2013).
The most challenging aspect of geothermal exploration is the quantification of subsurface temperature conditions. Actual temperature conditions often remain very uncertain as it is difficult to remotely measure through several hundreds of metres of solid rock. Only drilling through the rock layers will give information on the existing subsurface temperature. As drilling is very expensive (€1million to €15million), any low-cost pre-drilling temperature estimation can bring in huge added value. Electromagnetic (EM) technology that Doel & Stove (2016) has been developing and experimenting aims to find subsurface sources of geothermal heat prior to drilling.
Through empirical field experimentation, EM technology would appear to non-invasively and digitally provide a temperature proxy measurement of the subsurface without physical drilling the Earth’s crust. Although not everything is known about the technology’s capabilities, EM technology shows strong promise. Key aspects of the technology have been field tested, including depth and capacity to identify water. Even at this early stage of development, EM technology merits further investigation to enable efficient and optimal exploration of the natural resources useful for geothermal energy generation.
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Volumes & issues
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Volume 42 (2024)
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Volume 41 (2023)
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Volume 40 (2022)
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Volume 39 (2021)
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Volume 38 (2020)
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Volume 37 (2019)
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Volume 36 (2018)
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Volume 35 (2017)
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Volume 34 (2016)
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Volume 33 (2015)
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Volume 32 (2014)
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Volume 31 (2013)
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Volume 30 (2012)
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Volume 29 (2011)
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Volume 28 (2010)
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Volume 27 (2009)
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Volume 26 (2008)
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Volume 25 (2007)
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Volume 24 (2006)
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Volume 23 (2005)
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Volume 22 (2004)
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Volume 21 (2003)
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Volume 20 (2002)
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Volume 19 (2001)
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Volume 18 (2000)
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Volume 17 (1999)
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Volume 16 (1998)
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Volume 15 (1997)
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Volume 14 (1996)
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Volume 13 (1995)
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Volume 12 (1994)
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Volume 11 (1993)
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Volume 10 (1992)
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Volume 9 (1991)
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Volume 8 (1990)
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Volume 7 (1989)
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Volume 6 (1988)
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Volume 5 (1987)
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Volume 4 (1986)
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Volume 3 (1985)
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Volume 2 (1984)
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Volume 1 (1983)