Resource Estimation Research Articles

Optimal number of Monte-Carlo simulations for hydrocarbon resources probabilistic estimation

Background: Probabilistic resource estimation allows to assess the potential of oil and gas prospect, which is used for decision-making in the industry. The main result of the estimation is resource potential, expressed in probability distribution function of geological or recoverable hydrocarbon resources. Monte Carlo simulation commonly used for these purposes. It simulates the numerical value of the objective function.
 Aim: The aim of the work is to find the optimal number of Monte-Carlo simulations in the probabilistic resource estimation.
 Methods: Monte Carlo simulation is based on repeated calculation of the function describing the process using a random number generator. The function variable defined by statistical distributions is calculated using random number. Further, mathematical operations are performed on all variables of the function according to the mathematical model. Summarizing the obtained set of results, the statistical distribution describing the desired function is approximately estimated.
 Results: The accuracy of distribution function estimation increases with an increase of the number of simulations. However, this tend to increase the computation time. Thus, there is a choice between the speed and accuracy of the solution.
 The Latin hypercube reduces the influence of the random number generator imperfection, but intermediate calculations with Latin hypercube attenuate the decrease in the number of simulations compared to random sampling.
 Conclusion: Based on the results of the work, a logarithmic dependence of the calculation accuracy on the number of Monte Carlo simulations was obtained. In most cases, 10000 simulations with accuracy about 1% will be sufficient.

Discovery of anomalous gallium enriched in stone coal: Significance, provenance and recommendations

Gallium (Ga) is a critical mineral that plays an irreplaceable role in consumer electronics, clean energy technologies and the aerospace industry. Nowadays competition for gallium resources at the national strategic level has begun to emerge, but gallium resources are unevenly distributed globally, and their presence is not guaranteed. New discoveries revealed an average gallium concentration of thirty-one samples from M1, M2, M3 and M4 stone coal-bearing seams of the Cambrian strata on South Qinling Orogenic Belt in central China is 157 mg/kg (9.98–747 mg/kg), which is 27.6-fold higher than the global hard coal average, as well as the existing association of Mo–V–U–Cd–Zn–Ba–Se–Mg–Ni–Cu enrichment. Ga average of these coal seams are 344 mg/kg (M3, 44.5–747 mg/kg, n = 11), 270 mg/kg (M4, 14.3–270 mg/kg, n = 5), 53.8 mg/kg (M2, 22.6–75.4 mg/kg, n = 8) and 19.8 mg/kg (M1, 9.98–34.9 mg/kg, n = 7) respectively, as well as the thickness of approximately 6, 12, 8, and 20 m, which be close to or exceed to the boundary grade standard (30 mg/kg) and minimum recoverable thickness (0.7 m) of gallium resources exploration. These findings indicate that the Cambrian stone coal deposits, especially in the middle and late Cambrian period, should be considered as promising alternative sources of gallium. The anomalous gallium-enriched sediments originated from a complex combination of hydrothermal fluids, original biomass and terrigenous materials. For the M1 stone coal-bearing seams, gallium most likely occurred in the mode of GaAs, GaxIn1-xAs and GaO(OH), while modes of gallium in the M2 to M4 seams is interrelated with the organic affinity and clay minerals. The crude reserve estimate of gallium resources in central China is approximately 10.06 × 104 tons, corresponding to a super-large coal-hosted gallium ore deposit. The unique paleogeographic location and geological structure in central China resulted that this newly discovered deposit is a unique type of gallium-enriched deposit that has been discovered worldwide. These discoveries will provide the critical parameters when developing distinctive beneficiation processes and appropriate extraction procedures, as well as guidance and effective for future prospecting regions of gallium resources around the globe, involving a combination consider the distribution of regional deep–large fault zones and the middle to late Cambrian black rock series deposits.

Review of machine learning-based Mineral Resource estimation

Mineral Resources estimation plays a crucial role in the profitability of the future of mining operations. The conventional geostatistical methods used for grade estimation require expertise, understanding and knowledge of the spatial statistics, resource modelling, geology, mining engineering as well as clean validated data to build accurate block models. However, the geostatistical models are sensitive to changes in data and would have to be rebuilt on newly acquired data with different characteristics, which has proved to be a time-consuming process. Machine learning methods have in recent years been proposed as an alternative to the geostatistical methods to alleviate the problems these might suffer from in Mineral Resource estimation. In this paper, a systematic literature review of machine learning methods used in Mineral Resource estimation is presented. This has been conducted on such studies published during the period 1990 to 2019. The types, performances, and capabilities, of several machine learning methods have been evaluated and compared against each other, and against the conventional geostatistical methods. The results, based on 31 research studies, show that the machine learning-based methods have outperformed the conventional grade estimation modelling methods. The review also shows there is active research on applying machine learning to grade estimation from exploration through to exploitation. Further improvements can be expected if advanced machine learning techniques are to be used.

Thermal evolution and resources of the Bowland Basin (NW England) from apatite fission-track analyses and multidimensional basin modelling

Abstract Once highlighted for having significant shale gas resource potential, the Bowland Basin has been at the centre of both scientific and political controversy over the last decade. Previous shale gas resource estimates range from 10 3 to 10 1 TCF. Repeated events of induced seismicity following hydraulic fracturing operations led to an indefinite government moratorium and abandonment of operations across the mainland UK. We use apatite fission-track analyses to investigate the magnitude and timing of post-Triassic uplift and exhumation. Results indicate that maximum palaeotemperatures of 90–100°C were reached in the stratigraphically younger Sherwood Sandstone. We combine palaeotemperature predictions to constrain palaeo heat flow and erosion in regional basin models for the first time. Our results indicate variable maximum Late Cretaceous palaeo heat flow values of 62.5–80 mW m −2 and the removal of 800–1500 m of post-Triassic strata at wells across the basin. Regional 2D basin modelling indicates a gas-in-place estimate of 131 ± 64 TCF for the Bowland Shale. This reduces to a resource potential of 13.1 ± 6.4 TCF, assuming a recovery factor of 10%. These values are significantly lower than previous resource estimates and reflect the highly complex nature of the Bowland Basin and relatively unknown history of post-Triassic uplift, exhumation and erosion.

“Reasonable prospects” in mineral resource estimation and reporting

ABSTRACT A fundamental component of the Definition Standards for Mineral Resources is the requirement that the material have “reasonable prospects for eventual economic extraction” (RPEEE). The first adoption of the RPEEE requirement by a widespread group was in 1997 as part of the Denver Accord meeting and has since become an international standard. Mineral resource statements are prepared for mineral properties that are at various stages in the mining cycle, from the discovery stage through to the production stage. The confidence level of information available for the development of the input parameters for the technical and economic components of RPEEE varies greatly among stages. Consequently, the RPEEE assumptions may evolve with the stage of the mineral property as well. The economic aspects of RPEEE are commonly achieved by selecting appropriate input parameters for establishing a cut-off grade. The technical aspects can include consideration of such items as minimum widths, spatial continuity, and the application of appropriate constraining surfaces and volumes. In all cases, the responsibility of ensuring that the mineral resource statements are prepared in accordance with the requirements of the Canadian Institute of Mining, Metallurgy and Petroleum Definition Standards ultimately resides with the qualified person.

Steel Plant Wastes as a Resource of Rare Earth Elements and Rare Metals–Characterisation, Resource Estimation, and Economic Assessment

Steel Plant Wastes as a Resource of Rare Earth Elements and Rare Metals–Characterisation, Resource Estimation, and Economic Assessment

Edge Computing in Centralized Data Server Deployment for Network Qos and Latency Improvement for Virtualization Environment

With the advancement of Internet of Things (IoT), the network devices seem to be raising, and the cloud data centre load also raises; certain delay-sensitive services are not responded to promptly which leads to a reduced quality of service (QoS). The technique of resource estimation could offer the appropriate source for users through analyses of load of resource itself. Thus, the prediction of resource QoS was important to user fulfillment and task allotment in edge computing. This study develops a new manta ray foraging optimization with backpropagation neural network (MRFO-BPNN) model for resource estimation using quality of service (QoS) in the edge computing platform. Primarily, the MRFO-BPNN model makes use of BPNN algorithm for the estimation of resources in edge computing. Besides, the parameters relevant to the BPNN model are adjusted effectually by the use of MRFO algorithm. Moreover, an objective function is derived for the MRFO algorithm for the investigation of load state changes and choosing proper ones. To facilitate the enhanced performance of the MRFO-BPNN model, a widespread experimental analysis is made. The comprehensive comparison study highlighted the excellency of the MRFO-BPNN model.

BLOCK MODEL OPTIMIZATION AND RESOURCE ESTIMATION OF THE ANGOURAN MINE BY TRANSFERRING THE EXPLORATORY DATA FROM THE LOCAL COORDINATE SYSTEM TO THE UTM

Resource estimation is one of the most important steps in the mining process. Precise resource estimation has a significant influence on the optimization of subsequent mining steps, i.e. mine planning and scheduling. The previous resource estimation in the Angouran Mine was conducted based on the provided information in the local coordinate system which causes considerable errors in estimations. Therefore, an attempt is made in this research to optimize the block model of the Angouran Mine and resource estimation based on the information in the UTM global coordinate system. For this purpose, exploratory data is firstly transferred from the local coordinate system to the UTM environment. Then, block model optimization is conducted using indicator kriging (IK) in which the waste blocks are removed and the block model was optimized. Finally, resource estimation is performed using the inverse distance weighting (IDW) and simple kriging (SK) methods. After variogram analyses in different directions, it was found that the mine deposit is anisotropic. Also, validation results showed that the acquired correlation coefficient in the carbonate and sulfide sections for IDW, SK and IK is 0.86, 0.87 and 0.92, and 0.88, 0.87 and 0.92, respectively. Finally, the obtained grades and tonnages are compared with the actual data of the exploratory boreholes, mined blocks and previous resource estimation in the mine. Comparative results showed that the obtained grades and tonnages from both previous and new models are over-estimated and higher than the actual values. The minimum errors of grade estimation equal 46% and 23.1% for previous and new resource estimations (before and after the waste removal), respectively. Also, the mining errors of tonnage estimation are 50.29% and 28.37% for previous and new models, respectively. This field comparison proved that transferring the exploratory data to the UTM system, utilization of the IK to remove the waste blocks and applying the SK for resource estimation lead to the optimization of the block model and a reduction in the estimation error compared to the previous estimations for the mine.

Analysis of Empirical Bayesian Kriging Methods for Optimization of Measured Resources Estimation of Laterite Nickel

Laterite nickel deposits are formed from the intense weathering of ultramafic igneous rocks. The distribution of Ni content in an area does not always have a stationary data. One method of resource estimation and precise geological modeling is the Empirical Bayesian Kriging (EBK) method which is known to be able to perform precise estimates for stationary and non-stationary data. The results of this study were found that thickness of the limonite layer will increase as the slope decreases, while in the saprolite zone the thickness will increase with increasing the degree of slope up to the limit of 16°-25° then the thickness will decrease when crossing that limit. In the limonite zone, the concentration of Ni is maximally concentrated at a high degree of slope (>16°), while in the saprolite zone, Ni content is maximally concentrated on a slope of 16°-25° and then decreases in Ni content when passing through a slope of 25°. Validation of the estimation results and geological modeling using RMSE, MAE, MAPE, and linear regression in the limonite and saprolite zones indicate that the EBK method is a precise method for resource estimation and geological modeling.

A Fused Gaussian Process Modeling and Model Predictive Control Framework for Real-Time Path Adaptation of an Airborne Wind Energy System

This article presents a computationally tractable adaptive control strategy suitable for mobile systems operating in a stochastically and spatiotemporally varying environment by fusing Gaussian process modeling and receding horizon control. This strategy ideally manages the tradeoff between exploration (maintaining an accurate estimate of the stochastic resource) and exploitation (maximizing a performance index, which generally consists of harvesting the resource) subject to partial observability (stochastic resource only measurable at the system’s location) and mobility constraints, which are characteristic of dynamic systems. The case study in this article focuses on a crosswind airborne wind energy (AWE) system where the wind turbine tower is replaced by tethers and a lifting body, allowing the system to adjust its altitude, with the goal of operating at the altitude that maximizes net energy production in a wind environment that is changing in altitude and time. Real wind speed versus altitude data has been used to validate the strategy and results are presented for a variety of control strategies applied to a rigid wing-based AWE system.

Road maintenance: which future?

Since 2007, the Province of Pisa has developed and implemented an IT System to census the criticalities affecting the road assets managed, which has gradually been enriched with new road assets, up to the complete development in 2018 of a complex system of classification of criticalities surveyed and the degree of priority of intervention associated with each of these criticalities. The innovation of this IT System is that allows to update the Road Cadaster, also attributing a degree of priority for intervention.The system also makes it possible to do an economic estimate of the necessary resources, in order to quantify the maintenance needs. The criticalities recorded up to April 2021 along the road network under management, excluding the geometric criticalities not considered by our formula (they are evaluated by the software in a separate procedure), quantify the financial requirement for the Provincial road network (approximately 800 km) at over € 140 million; of these, more than 30% falls within the maximum degree of priority of intervention, all against annual resources (including extraordinary Ministerial funds) not exceeding € 7 million for maintenance interventions.In this dramatic picture, the issue of the responsibilities attributed to the road network operators overlaps when, starting from 2016, the concept of "road homicide" was introduced as per art. 589-bis of Italian regulation (“Codice penale”). Since then, there has been several cases in which road technicians were taken to courtrooms to prove their conduct, arguing that they have not committed omissions, and in any case, this is not always sufficient. Starting from the experience of the Province of Pisa, this article aims to analyse and at the same time to complain about the operating conditions of the technicians in the light of the current regulatory scenario.

РЕСУРСЫ БАРИТА, ЦВЕТНЫХ И БЛАГОРОДНЫХ МЕТАЛЛОВ В ХВОСТОХРАНИЛИЩЕ ТАЛМОВСКИЕ ПЕСКИ: МИНЕРАЛОГО-ГЕОХИМИЧЕСКИЕ И ГЕОФИЗИЧЕСКИЕ ДАННЫЕ

The estimation of barite resources (BaSO4) as well as resources of metals (Au, Ag, Cu, Zn, Pb) was made with the help of modern precision research methods at the Talmovskie Peskitailing dump (Salair Ridge). Processed ores at the tailings dump are characterized by a large vertical heterogeneity; primary (substantially non-oxidized) and oxidized sands are distinguished with Bacontents of 39 and 35 %, respectively. Grain-size classes lower 0.25 mm are the most productive from the point of view of barite. Such occurrence forms and typomorphic characteristics as color, morphology, grain size distribution, mineral paragenesis and inclusions are described for barite and metals. Geoelectric measurements have shown a horizontally-layered structure of the tailing dump, where the values of ER (21–50 Ohm•m) corresponds to the friable oxidized matter of low humidity (up to the depth of 70 cm), 0.1–20 Ohm•m – to primary, substantially non-oxidized matter. According to the results of electrical resistivity tomography, the volumes of both media were determined (48,000 and 53,000 cu), that, in comparison with the data on the concentrations of Ba, Pb, Cu, Zn, Au, Ag in them, made it possible to calculate the resources of metals within the studied area and, in some approximation, in the entire storage.

ВИКОРИСТАННЯ КОНТРОЛЬНИХ ПРОБ ДЛЯ ЗАБЕЗПЕЧЕННЯ І КОНТРОЛЮ ЯКОСТІ (QA/QC)

Іn geological exploration, the quality of the data underlying of resource and reserve estimation is critically important. According to various international regulations and current world best practices, Quality Assurance and Quality Control (QA/QC) programs are a necessary part of geological exploration. Quality Assurance (QA) is used to avoid the problems with quality, Quality Control (QC) is aimed at detecting them in case of their occurrence, and together they form the overall Quality System – QA/QC. The article considers the main stages of the history of QA/QC development, which begins in the Middle Ages and continues in our time. Control samples used to control analytical tests have different types and purposes / functions: standards, preparation blanks, coarse blanks, analytical blanks, field duplicates, coarse duplicates, pulp duplicates and umpire laboratory control. Their amount and ratio is the main topic of the research. According to the published data of nine different authors, the recommended control sample amount of each type is different. On average, the amount of control samples of all types is about 20% of the total number of routine samples. In order to highlight the current state of the issue, the authors of the article have analyzed 111 QA/QC programs for 87 ore projects according to the public reports disclosed by the issuers of the Toronto Stock Exchange. So, in practice, the control sample amount does not necessarily reach the recommended 20 % and is slightly more than 16 %. The main conclusions regarding the amount and ratio of control samples can be presented as follows: (1) the general increasing trend in the amount and variety of control samples is observed; (2) among the control sample types, the so-called standards are most often used, and the least used are coarse blanks; (3) the control sample amount and variety also depends on the mineral type; (4) at more advanced exploration stages of the project, the control sample relative number usually increases, but in some cases it may decrease if the results of the previous stages are satisfactory, and the methodology and laboratory are not changed.

An Adaptive Confidentiality Security Service Enhancement Protocol Using Image-Based Key Generator for Multi-Agent Ethernet Packet Switched Networks

Conventional network Security Protocols provide different types of security services that establish secure connections between network nodes making them robust against different security threats. The security establishment process depends on sharing security keys between connected devices. The level of security provided by such security protocols is static and irrelevant to the status of the network. In this paper, we propose an adaptive security-aware lottery-EDF scheduler for limited resources Ethernet packet switched networks using GAIA multi-agent approach. The proposed system adopts a periodic non-shared cryptographic key-generation process of different sizes (i.e., 64 bits, 128 bits, 160 bits, and 512 bits) using the textural features of digital images stored on a central image-server. The proposed system deploys a security enhancement unit that adaptively enhances the confidentiality security-service level for the real-time packets according to feedback from a congestion control scheme that is based on network resource estimation technique, hence making the network robust against the spoofing security threat while preserving the overall network performance metrics (NPMs). By simulating a real-time Ethernet packet switched network, extensive simulation results show the efficiency of the adaptive proposed protocol over the static-security and IPSec protocols in guaranteeing the QoS requirements for the real-time flows in terms of destination’s buffer consumption and average total packet delays.

예당호 일원 붕어와 떡붕어의 성장 형질

Age-related physiological characteristic of crucian carp inhabiting Lake Yedang were analyzed to compare the ecophysiological distribution of Carassius auratus (n = 1,537) and C. cuvieri (n = 1,385). Crucian carps were collected and analyzed biomass, gender, and hematological parameters by age group. Age distribution of one-year-old (OYO) fish were dominant group which is 27.3% and 28.7% for C. auratus and C. cuvieri, respectively, whereas the distribution of over five-year-old fish were decreased. OYO biomass of C. auratus and C. cuvieri were 42.0 g and 64.4 g, respectively. A distinct characteristic between two species were observed in four-year-old fish, i.e. C. cuvieri have shown an increase of biomass, total length, and body height in comparison to C. auratus. A distribution of OYO male and female were 43.3%, and 24.4%, respectively. However, the male proportion were decreased with age increase. Hematological analysis revealed that C. auratus collected in the season of spring and summer showed an increase of serum albumin and glucose, while carps collected in the season of summer and fall showed a decrease of cholesterol and an increase of calcium and globulin compared to those samples collected in the season of winter and spring. These results are considered to be effective for estimation and management of freshwater aquatic resources.

Modelling and Estimation of Coal Resources Using Circular Method in Beringin Makmur II Area, North Musi Rawas Regency

The Muaraenim Formation is a coal-bearing formation located in the South Sumatra Basin. The research location is in the Beringin Makmur 2 area, North Musi Rawas Regency, which is included in the Airbenakat and Muaraenim Formations. The aim of this research is to do 2-dimensional and/or 3-dimensional modeling in the research area to determine the feasibility of the mining process. The feasibility test of a coal seam body will be used as a study for the next stage, namely resource estimation. The method for calculating coal resources is the USG circularS method based on drill log data. The following data is needed, such as drilling data for 64 drill points, regional geological data and survey data at the research location or mining business permit (IUP) location. Then an analysis will be carried out so that 3D subsurface modeling and calculation of coal resources can be continued. Based on the research results, it was found that there were 3 coal seams with updip in the north direction and downdip in the south direction N1800E - N1820E. In the research area, synclines were found that affected the distribution of coal. Interpretation of the 3D model is obtained from the correlation between drilling data and survey data. The results of the calculation using the USGS circular method, the estimated tonnage of inferred resources is 91,840,000 tons, indicated resources are 55,330,000 tons, measured resources are 235,870,000 tons so that the overall estimate of the coal seams is 383,040,000 million tons/ton.

Machine Learning Based Framework for Fast Resource Estimation of RTL Designs Targeting FPGAs

Field-programmable gate arrays (FPGAs) have grown to be an important platform for integrated circuit design and hardware emulation. However, with the dramatic increase in design scale, it has become a key challenge to partition very large scale integration into multi-FPGA systems. Fast estimation of FPGA on-chip resource usage for individual sub-circuit blocks early in the circuit design flow will provide an essential basis for reasonable circuit partition. It will also help FPGA designers to tune the circuits in hardware description language. In this article, we propose a framework for fast estimation of the on-chip resources consumed by register transfer level (RTL) designs with machine learning methods. We extensively collect RTL designs as a dataset, extract features from the result of a parser tool and analyze their roles, and train a targeted three-stage ensemble learning model. A 5,513× speedup is achieved while having 27% relative absolute error. Although the effect is sufficient to support RTL circuit partition, we discuss how the estimation quality continues to be improved.

Výsledky druhej fázy geologického prieskumu hlbokomorských polymetalických konkrécií v prieskumnom území Spoločnej organizácie Interoceanmetal

The exploration rights of the Interoceanmetal Joint Organization for exploration of polymetallic nodules (PMN) are granted from 29 March 2001 to an area located within the Clarion-Clipperton Zone (CCZ) in the eastern central Pacifi c Ocean. Exploration area covers 75,000 km2 and consists of two sectors (B1 and B2). The B2 sector comprises four exploration blocks (H11, H22, H33 and H44). The most prospective area, selected for detailed research, is marked as H22_NE exploitable block and delineated within the H22 exploration block. The article presents results of geological survey, based mostly on the data collected during the second phase of exploration in the licence area (2016–2021, extension of the contract). Results are based on IOM’s expeditions and relevant analytical work. During the IOM-2018 expedition high resolution bathymetric survey of H11, H22, H33 and H44 exploration blocks was carried out. The IOM-2019 expedition provided a new set of the data obtained using the distance methods (side-scan sonar, profi ler) and contact methods (box-corer and gravity corer) in H22_NE exploitable block, H33 exploration block and preliminary delineated Preservation Reference Zone. The study was focused on analytical work based on sediment and nodule analyses of samples in H22 exploration block and H22_NE exploitation block. New estimation of mineral resources in B2 sector was caried out using the geostatistical method of ordinary block kriging with Yamamoto correction. The polymetallic nodule resources have been classifi ed within the Inferred, Indicated and Measured Resources categories of the CRIRSCO classification system.

Characteristics and Potential of Placer Gold Deposit in Lakan Bilem Block, West Kutai District, East Kalimantan, Indonesia

Kalimantan is recognized as one of Indonesian islands with huge prospect of minerals particularly gold both primary and secondary deposit styles. However, the publication of the gold resources is still restricted to be described in regional/district scale maps or exploration company internal reports, hence, a detailed study on deposit scale remains limited. This study is aimed to document the characteristics and the estimation of potential or resources of the secondary (placer) gold deposit in Lakan Bilem block, West Kutai district, East Kalimantan province, Indonesia. The study was done by field observation followed by microscopic analysis and simple resources estimation of the gold. Gold in the study area occur in the semi-consolidated paleo alluvial deposit as trace mineral. The gold morphologies show platy to angular form with coarse surface which indicates the process of gold deposition is predominantly controlled by hydrodynamic transportation at a relatively moderate regime. Estimation of the indicated resources of gold results a total of 4.96 tonnes of gold potentially occurred in the study area. Exploration drilling with 100 spacing grid is suggested to delineate lateral and vertical distribution of the gold deposit. The drilling also will upgrade confidence level of the resources from indicated to measured resources.

Resource Estimation in Multi-Unit Mineral Deposits Using a Multivariate Matérn Correlation Model: An Application in an Iron Ore Deposit of Nkout, Cameroon

Modeling the spatial dependence structure of metal grades in the presence of soft boundaries between geological domains is challenging in any mineral resource estimation strategy. The aim of this work was to propose a structural model adapted to this type of geological boundary, based on a multivariate Matérn model that fits the observed direct (within domain) and cross (between domains) correlation structures of metal grades. The methodology was applied to a case study of an iron deposit located in southern Cameroon. Cross-validation scores show that accounting for the grade correlation across domain boundaries improved the traditional workflow, where the grade was estimated in each domain separately. The scores were significantly better when we also ensured that the mean grade was locally invariant from one domain to another to reflect the grade continuity across the domain boundary.