Exploitation Process Research Articles

A Fully Coupled Gas–Water–Solids Mathematical Model for Vertical Well Drainage of Coalbed Methane

The coupling relationship between the deformation field, the diffusion field, and the seepage field is an important factor in fluid transport mechanisms in the long-term coalbed methane (CBM) exploitation process. A mathematical model of gas–water two-phase fluid–structure coupling in a double-porosity medium in coal reservoirs is established in this paper. Taking Hancheng Block, a typical production block in Qinshui Basin, as the geological background critical desorption pressure, reservoir permeability anisotropy is considered in the model. COMSOL Multiphysics (COMSOL_6.0) was used to create the model. The accuracy and rationality of the model were verified by comparing field production data with the results of the simulation. Using the simulation, the influence law of various reservoir geological characteristics parameters (Langmuir strain constant, ratio of critical desorption pressure to reservoir pressure of coal seam (CDPRP), elastic modulus, initial water saturation, Langmuir pressure, etc.) on CBM productivity, reservoir pressure, and permeability ratio was discussed, and a thorough analysis of the factors affecting productivity was obtained using the orthogonal test method. The findings of this study indicate that the change in permeability is the result of the superposition effect of many factors. Different stages of drainage have different primary regulating factors. Rock skeleton stress has a consequence on coal matrix permeability in the early drainage stage, and coal matrix shrinkage is primarily impacted in the later drainage stage. Besides the initial water saturation, other reservoir geological parameters (e.g., CDPRP, Langmuir volume, Langmuir strain constant, elastic modulus) have a strong relationship with productivity. When the value of coal geological parameters increases, the degree of productivity release is higher (as the initial water saturation increases, the production decreases correspondingly). Different coal and rock parameters have varying levels of impact on the drainage stage of CBM wells. The influences of the CDPRP, Langmuir volume, Langmuir strain constant, and elastic modulus on gas production are mainly concentrated in the initial and intermediate drainage stages and begin to fall off during the last drainage stage. Per the multi-factor analysis, the main coal–rock parameters affecting the productivity release are the Langmuir strain constant, followed by the CDPRP and other parameters. The analysis findings can offer theoretical guidance for CBM well selection and layer selection and enhance the block’s overall CBM development level. The improved productivity prediction model for CBM, which is based on fluid–structure coupling theory, can offer a new technical benchmark for CBM well productivity prediction.

Investigation of erosion behavior of particle-fluid flow in offshore platform T-pipes

The process of viscous oil exploitation is often accompanied by small sand particles, which harms safety production and causing consequences such as erosion. T-shaped pipes are widely used in offshore platform, and its flow protection is very important for the safe operation. This work aims to investigate the particle trajectory and erosion ratio rule in viscous oil transportation by simulation, experiment and support vector machine (SVM) model. The sensitivity analysis and the orthogonal method results demonstrate that the erosion ratio (ER) of T-pipes is proportional to the water content, gas content and sand content. And the erosion ratio (ER) of T-pipes is inversely proportional to the viscosity. The water content has the greatest effect on the pressure drop (Δp). The viscosity value around 326.79 mPa s can significantly reduce the erosion ratio while maintaining a low-pressure drop. Meanwhile, SVM model is used to calculate the erosion ratio (ER) with the mean squared error (MSE) being 4.25 × 10−6 in the training set and 0.0002 in the test set. The most severe erosion area is located in the downstream branch symmetrically. The erosion mechanisms are impact deformation and sliding, that dominate the erosion distributions.

Commodification of Workers in Tempo Magazine

Tempo Magazine commodifies workers through increased working hours, low wages, multiple tasks, and marketing promotions that become exchange value for the public. This research aims to reveal the commodification of workers in Tempo Magazine and fill the unique gaps in previous research. The paradigm used is critical because the researcher wants to show that Tempo Magazine journalists are considered commodities measured based on economic factors. Journalists are willing to exchange their labor and even spend time on holidays to meet sources for low wages. The data collection technique is carried out through observation; namely, the researcher observes the research object by classifying and combining articles in Tempo Magazine. Researchers also interviewed the Editor-in-Chief of Tempo Magazine, Tempo Magazine journalists, and eight former Tempo Magazine journalists as critical informants to see different sides of Tempo. The research results show that Tempo Magazine journalists do not apply a specific working time pattern when covering an issue. It is not uncommon for them to use their holiday time to meet sources. They are trapped in false consciousness and do not understand their exploitation by assuming that when they succeed in getting a source, it is a matter of prestige and will always be remembered. They also work more than regular hours but do not receive overtime pay or other compensation. In addition, photo works produced by journalists do not receive copyright protection. Tempo sold it without permission, and this is a copyright issue and protection of intellectual property rights in the media industry. The use or sale of images without permission can harm the creator financially and violate rights that should be protected. Journalists, as a profession that focuses on providing information, often support the human rights of others. However, they also face challenges and risks related to their human rights in their duties. Thus, this study confirms that worker commodification is for workers who are re-produced or renewed through exploitation processes such as increasing working time or intensifying the work process.

Changing natures: a perspective on youth and conservation futures

Conservation has been a largely exclusionary and exploitative process that has its roots in western colonial expansion. This paper offers a perspective on the relationship between the conservation apparatus and young adults who live in and around Protected Areas and have grown up within a conservation regime. Following Feminist Political Ecology's call to better understand the situated and heterogeneous relationships to nature within communities, I bring attention to the lives of Soliga tribal youth in a Tiger Reserve in South India. I challenge mainstream perceptions that youth inevitably want to leave their forest homes, arguing that the difficult choices youth must make today, are informed by decades of life under restrictive laws that alienate communities from the forest over generations. Young people's lives and aspirations are contradictory and nuanced, and their relationships to the forest remain strong and should not be discounted. This research contributes to a significant gap in the literature, and illustrates the need to include the experiences of youth as a central tenet of unfolding dialogues on inclusive and decolonial approaches to conservation.

Modeling of synthesized hydrate-bearing sands: Effect of hydrate morphology on absolute and relative permeabilities

Absolute and relative permeability of hydrate-bearing sediments are crucial flow parameters to hydrate exploitation processes. However, up to now, grain-coating hydrate-bearing sediments (GC-HBS) with high hydrate saturation (Sh) and pore-filling hydrate-bearing sediments (PF-HBS) are still prohibitive to be prepared in laboratory. In this work, three-dimensional pore structures of GC-HBS with high Sh and PF-HBS were numerically synthesized, based on the CT scanning of porous samples. Then, a state-of-the-art quasi-static pore-network model (PNM) was used to study the absolute and relative permeability of these HBS. Results show that the absolute permeability of both of the GC-HBS and PF-HBS declined rapidly with increasing of Sh, they can be well fitted by the Tokyo model with exponential parameter of 3.5 and 5.3, respectively. And the absolute permeability of PF-HBS is smaller than that of GC-HBS with same Sh for a bigger specific surface area of PF-HBS which increases the flow resistance for flows. It shows that the wetting and non-wetting relative permeability of GC-HBS decreases with the increase of Sh. But the gas-water two-phase relative permeability of PF-HBS has nonmonotonic changes with the increase of Sh.

A spherical evolution algorithm with two-stage search for global optimization and real-world problems

This paper proposes a spherical evolution algorithm with two-stage search. Spherical search and hypercube search are combined to achieve individuals' evolution. A self-adaptive Gaussian scale factor and a variable scale factor are designed to adaptively control individuals' spherical and hypercube search area according to their search situations. Two search stages frequently switch with four search cases to enhance the balance between exploration and exploitation processes. A directed adjacency matrix is devised to analyze the relationship among individuals from the perspective of graph theory. Experiments compare the proposed algorithm with five algorithms with distinctive search patterns on twenty nine CEC2017 benchmark functions. The diversity analysis and graph theory analysis show the good population diversity and effective information spreading of the proposed algorithm. Twenty two real-world problems evaluate the practicality and optimization ability of the proposed algorithm. Finally, the computational time complexity demonstrates that the proposed algorithm is more efficient than the original spherical evolution algorithm.

Review of Heat Transfer Characteristics of Natural Gas Hydrate

As a typical unconventional energy reservoir, natural gas hydrate is believed to be the most promising alternative for conventional resources in future energy patterns. The exploitation process of natural gas hydrate comprises a hydrate phase state, heat and mass transfer, and multi-phase seepage. Therefore, the study of heat transfer characteristics of gas hydrate is of great significance for an efficient exploitation of gas hydrate. In this paper, the research methods and research progress of gas hydrate heat transfer are reviewed from four aspects: measurement methods of heat transfer characteristics, influencing factors of heat transfer in a hydrate system and hydrate-containing porous media systems, predictive models for effective thermal conductivity, and heat transfer mechanisms of hydrate. Advanced measurement techniques and theoretical methods that can be adopted for the heat transfer characteristics of gas hydrate in the future are discussed.

Isu Politik Identitas Terhadap Identitas Politik Pada Generasi Mileneal Indonesia Di Era 4.0

Indonesia has a collective culture that illustrates the recognition of togetherness, mutual cooperation and cohesiveness. But it is also prone to conflicts if there are differences, especially in the generation of millennials who are easily herded through the power of social media or sophisticated communication media in the era of 4.0. Identity is politicized through various and extreme interpretations, which aims to get support from the millennial generation who feel 'the same', both in race, ethnicity, religion, and other adhesive elements so that movements or polarization of oppositional dichotomy features become easy to become the main foundation that differentiate feelings of collectivity so that exploitation is easy, then intolerance is increasing. The occurrence of social imagery mismatches about political identity and political identity that occurs in the current millennial generation. This study aims to determine the effect of the issue of identity politics towards political identity in Indonesian millennial generation in the 4.0 era and trying to answer the formulation of the problem, namely: first, describing the exploitation of identity political issues that began to develop in Indonesian society in the 4.0 era. Second: describing the process of political exploitation of identity political identity in the millennial generation. Third: finding implications of the meaning of the results of research and solutions that can add to the study of the exploitation of the issue of identity politics on political identity in Indonesian millennial generation in Era 4.0 so that it can be further investigated by subsequent researchers. The method used in this study is a qualitative method with descriptive analysis. The research subjects were 150 students, aged 19-21 years who provided research data through interviews, surveys and documentation with triangulation data processing in order to obtain valid research results. Based on the results of the study, the conclusion was drawn. the exploitation of the issue of identity politics against political identity in Indonesia's millennial generation in era 4.0.

A Numerical Investigation of the Nonlinear Flow and Heat Transfer Mechanism in Rough Fractured Rock Accounting for Fluid Phase Transition Effects

The study of the seepage and heat transfer law of three-dimensional rough fractures is of great significance in improving the heat extraction efficiency of underground thermal reservoirs. However, the phase transition effects of fluids during the thermal exploitation process profoundly influence the intrinsic mechanisms of fracture seepage and heat transfer. Based on the FLUENT 2020 software, single-phase and multiphase heat–flow coupling models were established, and the alterations stemming from the phase transition in seepage and heat transfer mechanisms were dissected. The results indicate that, without considering phase transition, the geometric morphology of the fractures controlled the distribution of local heat transfer coefficients, the magnitude of which was influenced by different boundary conditions. Moreover, based on the Forchheimer formula, it was found that the heat transfer process affects nonlinear seepage behavior significantly. After considering the phase transition, the fluid exhibited characteristics similar to shear-diluted fluids and, under the same pressure gradient, the increment of flow rate was higher than the increment in the linearly increasing scenario. In the heat transfer process, the gas volume percentage played a dominant role, causing the local heat transfer coefficient to decrease with the increase in gas content. Therefore, considering fluid phase transition can more accurately reveal seepage characteristics and the evolution law.

Adam Mickiewicz Museum in Śmiełów – towards a contemporary museum concept using digital twin technology

Modern demands and dynamic technological development, especially in the field of artificial intelligence (AI) and machine learning methods, require science to adapt and verify the existing methods. It also includes the fields related to the history of architecture and the cultural heritage protection. The concept of the digital twin – a virtual copy of a historic object which enables a deeper understanding of its structure and the optimization of the protection/preservation and exploitation process, is gaining popularity. The aim of the paper was to analyse the potential of the digital twin in the context of historic museum building, where museum collections are often subject to separate protection principles. The current state of research on digital twins, as well as the challenges associated with creating HBIM documentation and the problems faced by contemporary museums, was presented. The results of research carried out in 2022–2024 on the palace in Śmiełów, a branch of the Adam Mickiewicz Museum were also presented. Traditional technical documentation served as the basis for research, conservation work and the plans of the further expansion of the museum, as well as the creation of a new digital exhibition path. The conclusion highlights the prospects for developing the concept of a “museum in a monument” as an innovative form of presenting cultural heritage. A contemporary museum in a monument should combine tradition with modernity, and the “digital twin” can become a bridge between the past and the present, providing visitors with unique experiences.

Analysis of coal facies and parting in The Balikpapan formation, Kutai Basin, East Kalimantan

The research area is located in RKBM coal mining area in East Kalimantan. One factor that influences the presence of parting in coal is the depositional environment. The existence of coal partings in this open pit area needs to be analyzed to determine the following steps in the exploration and further exploitation processes. The purpose of this study is a geological survey with the aim of knowing the coal facies and its parting characterization. The research was done by surface geological observation and drilling method. The results show that the facies association in this mining associated with delta systems such as channel, back swamp, flood plain, levee, crevasse splay, and inter distributary bay. The open pit area is composed of dominant lithology deposited in the upper delta plain environment. The presence of many and thin partings are often found in coal associated with the back swamp facies and deposited in the upper delta plain environment, which is mainly associated with fluvial systems. The distribution of parting in the study area is interpreted as not widespread because it is associated with back swamps that are affected by flood plains, and sometimes their distribution is cut off by channels.

Multi-Agent cubature Kalman optimizer: A novel metaheuristic algorithm for solving numerical optimization problems

Optimization problems arise in diverse fields such as engineering, economics, and industry. Metaheuristic algorithms, including the Simulated Kalman Filter (SKF), have been developed to solve these problems. SKF, inspired by the Kalman Filter (KF) in control engineering, requires three parameters (initial error covariance P(0), measurement noise Q, and process noise R). However, studies have yet to focus on tuning these parameters. Furthermore, no significant improvement is shown by the parameter-less SKF (with randomized P(0), Q, and R). Randomly choosing values between 0 and 1 may lead to too small values. As an estimator, KF raises concerns with excessively small Q and R values, which can introduce numerical stability issues and result in unreliable outcomes. Tuning parameters for SKF is a challenging and time-consuming task. The Multi-Agent Cubature Kalman Filter (MACKO), inspired by the Cubature Kalman filter (CKF), was introduced in this work. The nature of the Cubature Kalman filter (CKF) allows the use of small values for parameters P(0), Q, and R. In the MACKO algorithm, Cubature Transformation Techniques (CTT) are employed. CTT can use small values for parameters P(0), Q, and R, so CKF was developed to overcome KF and other estimation algorithms. Moreover, in CTT, the term local neighborhoods is used to propagate the cubature point in local search, where the radius, δ, of local search is updated in every iteration to balance between the exploration and exploitation processes. MACKO is evaluated on the CEC 2014 benchmark suite with 30 optimization problems, and its performance is compared with nine existing metaheuristic algorithms. Simulation results demonstrate that MACKO is superior, outperforming the benchmark algorithms, as indicated by Friedman's test with a 5 % significance level.

Ship Rescue Optimization: A New Metaheuristic Algorithm for Solving Engineering Problems

<p>In recent years, more and more problems in the industry have started to be solved using metaheuristics. In this paper, inspired by the ship maneuvering motion function and the rescue process, we propose ship rescue optimization (SRO) to solve the challenging optimization problem. The ship rescue process can be divided into two types of delayed rescue (large area rescue) and immediate rescue (small rescue) according to the searched person, and we can correspond these two types of rescue behaviors to the search space exploration and exploitation processes, respectively. In this process, SRO simulates the motion process of ship rescue according to the ship maneuvering equation of motion and finally comes up with an optimal position update algorithm. We verified the performance of the proposed algorithm on different dimensions of 57 test functions consisting of CEC2013 and CEC2017 and on three real engineering problems, and compared it with eight current mainstream algorithms. The algorithm proposed in this paper is shown to be robustly applicable in solving challenging optimization problems.</p> <p> </p>

A novel process for recovery and exploitation of polyesters and polyamides from waste polymeric artifacts

Plastic waste is one of the world's biggest sources of pollution. Despite the growing trend towards recycling, there are currently no effective technologies to offset the continuous increase in plastic production. Polyesters and polyamides are among the most widely produced single-use plastics, mainly used in the manufacture of textiles and soft drink bottles. Currently, only a small proportion of these polymers can be effectively recycled. The two primary methods employed for this purpose are mechanical and chemical recycling. Presently, mechanical recycling remains the more widely adopted process within the industrial sector. However, the treatment process is limited to a narrow range of waste materials as it is impossible to remove dyes and the mechanical properties deteriorate due to incompatibility between different plastic materials. Another critical limit of this recycling technology is the limited number of recycling loops that can be done due to the thermal degradation that occurs during the extrusion process. The alternative option is chemical recycling, which allows the depolymerization of the original product to recover the monomers directly. The main drawbacks are the long reaction times and the many solvents needed to achieve high-purity products. As a results, chemical recycling is only economically feasible for large companies that can produce the virgin polymer in situ. In this work, a new technology has been patented. This process consists of three main steps. The first one is the distillation-assisted cyclodepolymerization (DA-CDP), introduced as a modification of the CDP process. In this unit, cyclic oligomers together with high molecular weight compounds are produced. Then, after polymer purification, it is possible to achieve the same molecular weight as the initial polymer in less than 30 min, exploiting the ring-opening polymerization (ROP) of the next step.

EVALUATING THE ENVIRONMENTAL LICENSING PROCESS OF MARINE CALCAREOUS ALGAE BY THE IBAMA IN BRAZIL: CONTRIBUTIONS TO INSTITUTIONAL LEARNING

Currently, the efforts of marine research and marine resources exploitation are rising. However, debate usually is divided into economic and conservation approaches. One procedure used in Brazil to achieve coherence between economic development and environmental management in exploitation of natural resources is the environmental licensing. In Brazil, this activity is relatively recent and so little is known about the actual negative environmental impacts. The goal of this paper was to evaluate the main positive and negative aspects from environmental licensing process of exploitation of marine algae in Brazil guided by the IBAMA, focusing on processes with operation license emitted or expired. This qualitative research and methodology was developed into different stages between 2014 to 2015, analysis of legislation, information in licensing online systems and consultation in the technical collection of IBAMA head office, in Brasília. From processes evaluated, some of the main negative aspects found were incomplete studies, occurrence of irregularities, time elapsed and judicial intervention. On the other hand, positive aspects were strategies to give more speed and efficiency to processes. For breaching the conditions of operating licenses, all these licenses were suspended. The improvement of environmental licensing is needed and very required by several actors. However, it needs a broad discussion that considers the institutional existing experiences and limitations, mainly under challenges and pressure in its operational, budgetary or political performance.

On the Global Economic Exploitation Process: Steady States and Stability Aspects for economic Networks with Scale-Free and Limited (Cut-Off) Transitions<br>—The Concrete Case of the European Union

On the Global Economic Exploitation Process: Steady States and Stability Aspects for economic Networks with Scale-Free and Limited (Cut-Off) Transitions<br>—The Concrete Case of the European Union

Specifičnosti izrade rudarskih projekata

Designing in mining represents the process of implementing conceptual solutions and requires a multidisciplinary approach to teamwork. Application of knowledge, experience, skills, and use of tools and techniques are elements of creativity in the function of realization of project requirements. Information technologies and software products are mechanisms that are necessary for achieving the objectives defined by the project task. Sophisticated design includes knowledge of information technology, and software programs, which have the role of facilitating the performance of operational tasks while ensuring a quick response to client requests. Designed project solutions must meet investment requirements with mandatory compliance with legal regulations. A prerequisite for this is clearly defined goals and guidelines, as a reliable basis for the implementation of the project. The starting point in the development of mining projects is the input parameters. The quality definition of initial conditions is the result of using a database with as many elements as possible. The design process needs to include as many inputs as possible, such as the natural environment, geology, geotechnics, hydrogeology, ecology, etc. Gathering information needed for testing, calculations, analysis and harmonizing the results of modulated solutions affects the making of correct conclusions. In the absence of information, which is important for a safe, reliable and efficient functioning system of the exploitation process, the monitoring and control of such operations are to a considerable extent subject to risks. Solving unexpected problems is much more demanding to find adequate solutions for timely production process planning.

Method of determining time for preventive diagnosis in city bus operation systems

The article presents a mathematical model of the process of diagnosing and repairing preventive public transport buses. The mathematical model was developed using the theory of semi-Markov processes. The presented model considers two types of corrective repairs - carried out by the Technical Emergency Service and at Service Stations, and preventive repair. The presented model of the exploitation process system has been described to a small extent in the literature so far. The considered system is analyzed on the basis of two criteria: the availability of public transport buses and the profit per unit time. For the adopted assumptions, the conditions for the existence of an extremum of the criterion function were formulated. In the article, the presented model is illustrated based on sample results.

Salt exploitation by dissolution – an alternative method to reduce post-closure risks

During the last century, the mine closure frequency had significantly increased, therefore important environmental issues affect the public safety and the sustainable development process of the mining areas. The customary method of salt exploitation by dissolution uses the flooding of the formed caverns as the last step of the exploitation, which permanently isolates the caverns. In this case the rock-mass equilibrium inside the cavern changes, calamities such as seismicity, subsidence and collapse occasionally occur. Quite a few times, human settlements, civil buildings or industrial constructions located at the surface are affected. The present paper discusses adopting an alternative salt exploitation method by dissolution which offers the possibility to extract the entire salt deposit. This allows monitoring the stability factors linked to the exploitation process - the collapse that will occur as monitored represents the latter part of the method. It finally offers the opportunity to reclaim the water surface formed as a sustainable development goal and to reduce the long-term risks for calamities.

Geological Science and the Making of Colonial Oil Frontiers on the East Coast of Sumatra, 1890-1930

In the early 20th century, the Dutch Empire emerged as a prominent oil producer internationally, with the Netherlands East Indies leading the way in petroleum production. The colonial petroleum industry’s success was bolstered by scientific and technological advancements that streamlined the oil exploitation process. Geology played a critical role as a scientific tool that facilitated the conquest of landscapes and crude oil control along Sumatra’s east coast. The study of geology supported the colonial oil politics, leading to a new era of oil mining exploitation through robust economic partnerships between the Dutch colonial government and private oil companies. This paper aims to explore the link between Dutch colonial scientific agency and the establishment of an oil extraction territory that transformed the natural environment and social conditions on the east coast of Sumatra, from Aceh to Palembang.