Logging Operations Research Articles

Анализ факторов негативного воздействия лесозаготовительного производства на природную среду Северо-Западного региона РФ

Logging operations and timber transportation have a negative impact to natural and natural-anthropogenic
 environmental objects. Accounting, evaluation and forecasting of negative impact types will allow rational planning of
 technological logging operations. The negative impact degree data will allow assessing the total damage to
 environmental objects and, taking into account the loads of a particular work types provide for a set of protective
 measures adequate to the corresponding impact degree. The impact degree of types of logging activities to the
 environment was determined using the method of expert assessments. The variability of the nature and significance of
 the technogenic impact from logging and removal of wood was studied by the method of principal components. The
 generalized list of types of negative impact is ranked in the direction of decreasing degree as follows: pollution of water
 runoff and soils by leaks of fuels and lubricants, changes in biodiversity, damage to forest stands, destruction and
 pollution of soils, air pollution with chemical impurities, wastewater discharges into water bodies, landfill of domestic
 waste and discharge of effluents into the soil. When assessing biodiversity, increased attention should be paid to the
 organization of household and auxiliary technological processes. They are characterized by medium loads, causing
 pollution of water and soil by domestic and industrial effluents, and the formation of landfills for domestic and
 industrial waste. The construction of forest roads and work on refueling, repair and maintenance of logging equipment
 in workshops and fuel filling stations contribute to the manifestation of atypical impacts in the form of water and soil
 pollution with oil products. The obtained theoretical substantiation must be supplemented with relevant data from field
 studies on the identified types of negative impacts. Based on the predicted values of the degree of negative impact on
 the environment, the authors develop a set of scientifically substantiated technical and technological solutions that
 increase environmental safety during logging operations

Data-driven wireline sticking risk assessment and control factor analysis

The risk of wireline sticking cannot be accurately predicted at wireline logging site. Once the wireline is sticked on the wellbore, it seriously affects the logging process. A data-driven risk assessment method has been proposed to quantitatively predict and qualitatively evaluate the probability of wireline sticking accidents. Firstly, based on the data collection capability and expert experience, the risk characterization parameters of wireline sticking were determined. Secondly, according to the operating conditions of wireline logging, the variable length window data acquisition method and risk calibration were established, and the data feature extraction and feature selection methods were established. Thirdly, 149 logging operation records were collected to establish training data, and synthetic minority over-sampling technique (SMOTE) algorithm were used to expand the number of training data. Finally, a probability prediction model based on co-training-style random forest (Co-Forest) was established to quantitatively predict the probability of cable jamming. And the critical risk probability value is observed by fuzzy clustering to define the risk level. The performance of the proposed method was verified by logging operation records from an oilfield from 2019 to 2022, and the prediction accuracy was more than 90%. The results show that the model has good guiding significance and practicability for realizing intelligent wireline logging operation safety warning. The proposed method can be used to determine the depth of wireline logging operations and avoid wireline sticking.

Radial and vertical variation of wood nutrients in Bornean tropical forest trees

AbstractNitrogen, phosphorus, potassium, calcium, and magnesium concentrations in woody tissue are poorly documented, but are necessary for understanding whole‐tree nutrient use and storage. Here, we report how wood macronutrient concentrations vary radially and along the length of a tree for 10 tropical tree species in Sabah, Malaysia. Bark nutrient concentrations were consistently high: 2.9–13.7 times greater than heartwood depending on the nutrient. In contrast, within the wood both the radial (sapwood vs. heartwood) and vertical (trunk bottom vs. trunk middle) variation was modest. Higher concentrations in sapwood relative to heartwood provide empirical support for wood nutrient resorption during sapwood senescence. Dipterocarp species showed resorption rates of 25.3 ± 7.1% (nitrogen), 62.7 ± 11.9% (phosphorus), and 56.2 ± 12.5% (potassium), respectively, while non‐dipterocarp species showed no evidence of nutrient resorption in wood. This suggests that while dipterocarps have lower wood nutrient concentrations, this family is able to compensate for this by using wood nutrient resorption as an efficient nutrient conservation mechanism. In contrast to other nutrients, calcium and magnesium tended to accumulate in heartwood. Wood density (WD) showed little vertical variation along the trunk. Across the species (WD range of 0.33 to 0.94 mg/cm3), WD was negatively correlated with wood P and K concentration and positively correlated with wood Ca concentration. As our study showed exceptionally high nutrient concentrations in the bark, debarking and leaving the bark of the harvested trees on site during logging operations could substantially contribute to maintaining nutrients within forest ecosystems.

Lesson learned from the assessment of planned converted CO2 injection well integrity in Indonesia – CCUS project

The risk of CO2 leakage from carbon capture, utilization, and storage (CCUS) wells and geological storage sites must be properly assessed before the implementation of CO2 injection. According to ISO 27914 and ISO/FDIS 27916, the design and construction of an injection well needs to guarantee safety and ability to contain the stored CO2 over a long-term period. However, these standards alone were inadequate to evaluate the well integrity due to the need to specify criteria, duration of measurement, and range of measurement parameters of the available tools according to industries’ best practices.The methodology used in the study adapted applicable and readily-available international standards, field experiences, and lessons learned that could be used to support the construction of new and/or the conversion of existing oil and gas wells into CO2 injection wells. This study focused on Jepon-1 in Gundih field, Indonesia, an abandoned oil and gas well. Its actual conditions, well integrity, capabilities of the equipment used in the workover and logging operations, and its limitations in checking the conditions of various crucial aspects of integrity, were evaluated. The results showed that the application of the international standards could not fulfill all the detailed requirements of integrity evaluation of the JPN-1 well due to its particular condition and situation. Other field experiences needed to be adapted, improved, and incorporated in the integrity evaluation of this well. Additionally, longer duration of measurement and more accurate and sensitive logging evaluation tools, combined with temperature logging tools, are required to detect leakage that could not be identified by the commercial tools used in this well.The result of this well integrity study will be used as a fundamental basis for constructing CCUS well regulations by the Government and stakeholders.

A scenario-based metaheuristic and optimization framework for cost-effective machine-trail network design in forestry

Designing an optimal machine trail network is a complex locational problem that requires an understanding of different machines’ operations and terrain features as well as the trade-offs between various objectives. With the overall goal to minimize the operational costs of the logging operation, this paper proposes a mathematical optimization model for the trail network design problem and a greedy heuristic method based on different randomized search scenarios aiming to find the optimal location of machine trails —with potential to reduce negative environmental impact. The network is designed so that all trees can be reached and adapted to how the machines can maneuver while considering the terrain elevation’s influence. To examine the effectiveness and practical performance of the heuristic and the optimization model, it was applied in a case study on four harvest units with different topologies and shapes. The computational experiments show that the heuristic can generate solutions that outperform the solutions corresponding to conventional, manual designs within practical time limits for operational planning. Moreover, to highlight certain features of the heuristic and the parameter settings’ effect on its performance, we present an extensive computational sensitivity analysis.

Determining the optimal angle of traction force application of a "walking sledge" skidding device

Problem. Rounwood skidding is one of the most important operations during a timber harvesting. Often, especially during the shelterwood and improvement felling, it is necessary to use small-sized means of mechanization, including horse traction. For the effective use of horse traction, it is advisable to use special means that would facilitate the work of animals and allow to achieve appropriate labor productivity on skidding operation. The most famous and numerous auxiliary devices for horse timber skidding are various carriages whose design is constantly being improved. However, the carriages have proven themselves well on soils with high bearing capacity. On moistened and overmoistened soils, during the movement of such carriages with load, significant resistance to the rolling (movement) of the carriage’s wheels occurs, due to the significant wheels’ subsidence in the soil and the appearance of soil prisms in front of the wheels in the direction of movement. Even greater complications arise, when an obstacle appears - a stone, stump, etc. Then the movement of the wheel, depending on the obstacle, is impossible or requires a significant increase in the traction force. Therefore, the development of environmentally safe and energy-saving technologies and equipment for timber logging in complicated, particularly swampy, forest usage conditions is an important task for forestry scientists. Goal. The purpose of the research is to confirm the effectiveness of the skidding device "walking sledge" (obtained theoretically), namely to determine the optimal angle of traction force application for moving the device in the presence of obstacles. Methodology. Experimental studies were carried out with the use of a small-sized skidding device "walking sledge" in laboratory conditions with three different weights of the wood package (load), on surfaces with different sliding resistance coefficients, namely on a surface with a low coefficient of movement resistance (chipboard), on a surface with a high coefficient of movement resistance (concrete) and snow cover, which simulates the real conditions of the skidding device usage. The movement of the skidding carriage was carried out with and without an obstacle. Results. As a result of the conducted experimental studies, the optimal angle of traction force application for moving the skidding device "walking sledge" during its movement in a cutting area in the presence of obstacles has been determined, which lies in the range of 15°-19°. Originality. The small-sized skidding device "walking sledge" has been developed at the Ukrainian National Forestry University, which combines the advantages of both a sliding-type mover and a wheeled-type mover [1]. Such device is intended for use in a complicated conditions of forest usage, namely on swampy cutting areas. The carriage mover, when it meets with an obstacle or when it is “immersed” in the swamp, scrolls and makes a step. The proposed device received a utility model patent № 109011 [2]. Practical value. The proposed skidding devise "walking sledge" has shown its effectiveness when used in conditions closed to real ones and is recommended for usage during logging operations in moistened and waterlogged plots of forest cutting areas.

EXPANSION AND NATURALIZATION OF ADVENTIVE BUTTERFLY SPECIES (LEPIDOPTERA: PAPILIONOIDEA) ON THE NORTHEASTERN PART OF THE RUSSIAN PLAIN

Data on composition and naturalization patterns of more than twenty adventive butterfly species expanded to the northeastern part of the Russian Plain during the period of 1990-2021 are compiled. It is shown that lines of transport communications such as highways, railways, power lines, gas and oil pipelines serve as main immigration corridors for butterfly species from southern regions. Anthropogenic transformation of indigenous taiga forests through industrial logging operations, largely expanding areas of open habitats, which are more suitable for butterflies, promotes successful naturalization of adventive species. Linear systems of technical and industrial constructions together with river valleys play a role of semi-natural corridors for the expansion of adventive species. Furthermore, secondary small-leaved and mixed forests surrounded by a network of forest edges and meadows represent a kind of staging areas for the establishment of adventive species’ populations. Groups of adventive species are delineated based on their naturalization status that was estimated on the basis of an integral assessment of their biocenotic stability and landscape activity. It is drawn a conclusion that ongoing expansion and naturalization of adventive butterfly species on the northeastern part of the Russian Plain will increase changes in the composition of local and zonal faunas and the spatial and typological structure of their populations.

The Implementation of Anti-Illegal Logging Law in Eastern Visayas: An Assessment

Illegal logging contributes to conflicts with the local populations, political violence, funding armed conflicts, and worsening poverty. The main objective of this study was to determine the extent of the implementation of anti-illegal logging law in Eastern Visayas. Also, it aimed to identify the actions of the implementing agencies to the illegal logging activities and reasons why it persists. Purposive sampling was utilized to identify the eighteen forest protection officers from PENRO and CENRO of DENR and fifty-one police personnel in selected police stations. An explanatory sequential mixed method was employed in this study, using a combination of quantitative and qualitative descriptive approaches. The findings revealed that forest law enforcers implemented the anti-illegal logging law in Eastern Visayas. The study further revealed no significant difference in the perception of the forest protection officers and the police respondents regarding the implementation of anti-illegal logging law. The actions taken by the implementing agencies were in coordination with other implementing agencies, anti-illegal logging operations conducted, apprehension, confiscation of logs, wood, chainsaws, and conveyances, and appropriate charges filed towards timber poachers The reasons why the problems persist were the lack of livelihood programs, timber poaching as a regular occupation, economic and political factors, minimal penalties, inadequate manpower, and noncooperation of the community. Thus, the anti-illegal logging law should be further carried out to protect the forest and the people’s general safety. Keywords: Criminology, Anti-illegal logging law, mixed methods, Philippines

Logging operations creating snags, logs, and stumps under open and closed canopies promote stand-scale beetle diversity

Conservation tools to enrich habitat diversity in the widely distributed homogeneous production forests include stumps as logging residues but also the intentional creation of logs or snags, as well as varying canopy conditions. While an open canopy has been shown to foster forest biodiversity, the impact of different deadwood types at stand scale is less clear, which is crucial since this is the most relevant scale for silvicultural decisions. In this study, we experimentally manipulated canopy conditions (open vs. closed) and created deadwood (stumps, logs, snags) in different combinations in five mature European beech (Fagus sylvatica L.) forests to test the potential of active manipulations to increase the diversity of beetles, one of the most diverse insect orders in temperate forests. We estimated abundance, species number and species richness (controlled for abundance) of saproxylic (i.e., deadwood-dependent) and non-saproxylic beetles using flight-interception traps and analyzed species assemblages within the first 3 years of the experiment. Using generalized linear mixed effect models we found a 33.7 % and 43.4 % higher abundance as well as a 26.1 % and 23.5 % higher species number under open canopies for saproxylic and non-saproxylic beetles respectively, accompanied by a higher species richness of both groups. Stands with deadwood had a 38.6 % and 32.7 % higher species number followed by higher species richness of saproxylic and non-saproxylic beetles compared to stands without manipulation but manipulations did not affect beetle abundances. We identified sampling year, followed by canopy condition and deadwood type (in addition to an overall higher impact of spatial distance between stands and sites) by applying multiple regression analyses as most important to explain species assemblages of both beetle groups. Saproxylic abundance and species number in stump treatments were initially high but decreased over 3 years, while treatments containing snags and logs resulted in an increase in both abundance and species number over time. These temporal trends were mediated by canopy cover. Our findings provide three major insights for biodiversity-orientated management in mature beech forests: First, opening the canopy increases the stand-scale abundance, species number, and species richness of saproxylic and non-saproxylic beetles. Second, while stumps are attractive for saproxylics shortly after the logging operation, snags and logs provide longer-lasting deadwood resources, thus underlining longer sustainability of snag and log enrichment for forest biodiversity. Third, deadwood enrichment at the stand scale promotes not only deadwood-dependent but also other beetle species.

Обоснование технологических процессов и систем машин для лесосечных работ

The work analyses the forest raw material resources of the Far Eastern Federal District. Corresponding to the conclusions, it is made an evaluation of a promising technology and systems of machinery for logging. It shows the significance of logging development for the rational exploitation of forest resources and the economic progress of the Far Eastern Federal District. It is performed an analysis of different technological procedures for timber harvesting. The study gives a mathematical model for the evaluation of forestry companies by economic efficiency, regarding the resolution “The Strategy for the Development of the Forest Complex of the Russian Federation Until 2030”. The examination of the region’s forest resources reveals that, currently, in coniferous forests, up to 60 % of industrial wood is available from the total volume of timber for harvesting. However, the sawlog of 1–2 classes contains only 30–35 % of this volume. Within the framework of the research conducted in the developed cutting areas are established territorial-technological plots, in which logging residues are produced and collected. In these plots, the types and the volumes of the abandoned wood are determined. It is estimated that approximately 40–50 % of the annual volume of the timber released for logging is left as a trunk lowvalue timber and forest residues at cutting areas and loading points. The article gives a proposal fоr the automation systems and technologies for harvesting in mixed stands with low-valued wood class, which allow to increase the degree of usable wood, reduce risks from littering and provide in the future various regional forestry companies with row materials. The represented mathematical model on determination of economic efficiency and cost-effectiveness of technological process allows to make rational decisions on the implementation of bucking program of forestry company. For citation: Ryabukhin P.B., Kunitskaya O.A., Grigoreva O.I. Substantiation of Technological Processes and Machinery Systems for Logging Operations. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 2, pp. 88–105. (In Russ.). https://doi.org/10.37482/0536-1036-2023-2-88-105

Sparing old-growth maximises conservation outcomes within selectively logged Amazonian rainforest

Timber extraction threatens a vast area of tropical ecosystems, making it vital to design productive harvesting operations that limit biodiversity declines. Contrasting management options span a continuum from less-intensive, land-sharing logging applied over a larger area to land-sparing operations that combine intensive harvesting with the preservation of old-growth forest. Combining company-reported extraction rates with dung beetle surveys along an Amazonian logging gradient, we explore how individual species' abundances, geometric mean population sizes, functional diversity, and trait characteristics vary across simulated logging concessions and production targets. We substantially extend previous studies by evaluating 8000 mixed-harvesting scenarios and by assessing the profitability of contrasting practices. Simply maximising old-growth protection delivers the highest species' abundances and population sizes for species negatively affected by logging. Maximising old-growth also supports communities with a functional trait dissimilarity (FDis, RaoQ) and functional structure of nesting guilds, biomass, pronotum volume, front leg area, and front:back leg ratio traits that closely resembles old-growth forest. Functional evenness (FEve), richness (FRic), and divergence (FDiv) did not vary across logging strategies. Some 3 % of mixed approaches outperform extreme sparing (which maximises old-growth retention through intensive logging) but still involve substantial sparing, enabled by intensified logging elsewhere. However more-extensive business-as-usual harvesting is up to 90 % more profitable than extreme sparing, suggesting active policy mechanisms, standards, or regulations would be needed to make spatially-concentrated logging operations (which benefit biodiversity) more commercially attractive. Old-growth sparing appears key to limiting biodiversity declines within tropical timber concessions, but would require payments to compensate for reduced profits.

Logging and Indigenous peoples' well-being: an overview of the relevant international human rights jurisprudence

Logging activities worldwide occur on lands that are already inhabited and used by Indigenous peoples and other local communities and often cause negative impacts on those communities. International human rights law provides one framework within which to understand these impacts. In particular, a discrete body of rights within international human rights law pertain to Indigenous peoples. Encroachments on Indigenous lands, such as through logging or other forestry operations, often run up against the full spectrum of Indigenous peoples' rights, all of which are interdependent and interconnected. Numerous human rights bodies, including the United Nations treaty bodies and regional human rights courts, have addressed Indigenous rights in the context of logging and other extractive activities. This article reviews existing jurisprudence elaborating the scope of these rights and explains how respect for land and participation rights can help prevent impacts on other rights. International human rights jurisprudence outlines three steps as core components of Indigenous peoples' participation rights and as safeguards to protect other rights: conduct environmental and social impact assessments; engage in consultations with the affected Indigenous peoples with the aim of obtaining free, prior, and informed consent; and agree on benefit sharing, compensation, prevention, and mitigation measures with the affected Indigenous peoples. However, these requirements, and respect for Indigenous peoples' rights more broadly, remain to be effectively implemented and observed in practice.

Exploring Species Extraction Volume and Residues of Illegal and Conventional Logging Operations

Governments, policymakers, at most public fora, condemn activities of chainsaw operations as illegal and in fact, it has been criminalized with an explanation that it is wasteful and destructive to the environment. The study compared species, diameter distribution, extracted, volume, and residues generated during conventional and illegal logging operations in the forest communities. Using quantitative design approach, the researchers estimated the volume of waste generated by illegal logging and that of conventional loggers and also identified the species targeted. In order to determine the diameter distribution of exploited species, and the recovery rate of logs in both reserves, the researchers measured both ends, diameter, and length of stump wood and merchantable branch wood left as waste using the smallian's formula. The total volume of logs utilized per tree (logvol) was then calculated as the sum of the volume of each log. Twenty-five commercial timber species were identified to have been felled on farmlands compared to 34 commercial species which were felled in the TBFR. On both the farmlands and in the TBFR, the number of species felled by chainsaw operators far exceeded those felled by the conventional loggers. On farmlands, only four (17%) out of the 25 timber species were felled by conventional loggers. The most dominant timber species felled by the conventional loggers on farmlands was ceiba which comprised more than half (53%) of the total trees felled, followed by yaya (32%), watapuo (Cola gigantea), and akasaa (Chrysophyllum albidum). The study concluded that not only do chainsaw operators target a variety of lumber species but they also exploit timber species that are near extinction, therefore, making their activities pose danger to species diversity and conservation. The study proposed that strengthening the policy regime on compensation payment could help reduce the Incidence of illegal logging.

Wireline Logging Operation Uses Water-Based Drilling Fluid in HP/HT Gulf of Mexico Well

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 210021, “Wireline Logging in High-Overbalance, High-Pressure/High-Temperature Deepwater Gulf of Mexico Well With Water-Based Reservoir Drilling Fluid,” by Martin Tjioe, Jeremy McCaslin, and Jonathan J. Brege, SPE, Shell, et al. The paper has not been peer reviewed. _ Openhole wireline logging, because of its lower overpull capacity relative to logging while drilling, is subject to increased stuck-tool risk. The risk increases in higher-overbalance environments typical for depleted reservoirs, but other aspects of sticking risk can be managed. The complete paper describes the measures taken in an openhole wireline-logging operation in a deepwater Gulf of Mexico (GOM) well under nearly 7,000-psi overbalance in a high-pressure/high-temperature (HP/HT) slimhole environment using water-based reservoir drilling fluid (RDF) to achieve an efficient logging operation without incurring lost time attributed to conveyance-related issues. Introduction The wireline data-acquisition program was planned for an injector well in the deepwater GOM development field. The goal of the well was to maintain reservoir pressure through waterflooding, maximize recovery, and appraise the downdip portion of the fault block. The target was an aeolian sandstone reservoir at a depth of approximately 25,500 ft total vertical depth subsea featuring 19% porosity and permeability in the tens-of-millidarcy range. The reservoir had depletion of 6,850 psi; the well penetrated 174 ft of the reservoir with a hole size of 7 in. and a deviation of 25°. The injector used an openhole stand-alone-screen completion concept. Water-based RDF was used so that filter-cake material could be removed using a breaker fluid to enable matrix injection. Using a 13.5-lbm/gal mud weight, the wireline operation was performed under a downhole pressure of 17,900 psi (overbalance of 6,950 psi). The maximum temperature recorded during wireline was 320°F. Wireline Data-Acquisition Program The wireline program’s objectives were to acquire safely a profile of pressures and mobilities to identify depletion boundaries and to inform completion operations and acquire temperature data to infer the static formation temperature. During the planning phase, the well was classified as highly challenging, with a high risk of differential sticking based on the analog wireline jobs in the field. The well of interest penetrated the reservoir with the highest depletion encountered in the field at the time; because of its downdip location, it also had one of the higher downhole temperatures in the field. Several learnings from analog wells that are further detailed in the complete paper included the following: - Necessity of good hole cleaning - Reduction of toolstring length - Necessity of a water-based RDF with good fluid properties

Lumber sleuths

To enforce laws and treaties that protect endangered tree species, federal agents first have to recognize those species when they come across wood they suspect came from illegal logging operations. A US Fish and Wildlife Service lab has spent a decade developing a mass spectrometry approach to rapidly identify wood by species. Now the scientists are taking it on the road. Some years ago, David Gehl made an unusual trip to Siberia. “I went to lots of sawmills and forests and came back from Russia and China with, like, 20 kg of wood boards on my back,” he recalls. Gehl was no ordinary tourist. He was in the region as part of an undercover probe by a nonprofit group called the Environmental Investigation Agency (EIA). He was following up on suspicions that oak imported into the US from China had come from forests in eastern Russia where logging was prohibited.

Use of virtual reality technology in chainsaw operations, education and training

AbstractWood harvesting operations represent one of the industrial sectors with the highest risk of accidents at work. In semi-mechanized logging operations, the great majority of accidents generally occur using chainsaws during tree felling. Unfortunately, these situations frequently cause serious injuries and even the deaths of workers. In numerous cases, the accidents occurred to people who were badly trained and inexperienced, with a short employment history. One solution to reduce these harmful events is to support workers employed in this sector with training applications. This paper presents a description of a research and training programme for operating with chainsaws in tree felling operations using a Virtual Reality (VR) application called ForestVRoom. This innovative education method was compared with the traditional theoretical lesson based on a slide show. The results of the training were verified through a statistical analysis of questionnaires administered to a sample of 45 students in undergraduate and master’s degree programmes at the School of Agriculture and Forestry at the University of Florence. We have shown that the combination of traditional didactics and symmetrical collaborative VR leads to an increase in knowledge and especially in the ability to understand situations in a real forest site. VR is a useful teaching tool that can complement conventional training methods because of its potential to provide an immersive and attractive experience that facilitates learning and recognition of situations in forest sites.

Fossil-fuel consumption and CO2eq emissions of cut-to-length industrial roundwood logging operations in Finland

The aim of this study was to measure and model the fuel consumption of cut-to-length (CTL) logging machinery in cutting and forwarding under Nordic harvesting conditions, and to clarify which factors had the greatest effect on the fuel consumption. In addition, the total annual fuel consumption and CO2eq emissions were calculated for CTL logging operations in Finland in 2020. The data were collected during a long-term follow-up study on the fuel consumption of harvesters and forwarders conducted between March 2018 and April 2019. The fuel consumption data were obtained from a total of 16 harvesters and 13 forwarders equipped with digital flow metres featuring an accuracy of ± 1% of the fuel volume measured. The engine power of the forest machines explained most of the hour-based fuel consumption. Correspondingly, the harvesting conditions of the forest stand best explained the cubic-metre-based fuel consumption. The fuel consumption of CTL logging operations (cutting and forwarding) averaged 1.4 L m−3 in final felling, and 3.1 and 2.2 L m−3 in first and later thinning, respectively. There was a large variation in the cubic-metre-based fuel consumption between individual machines, both for harvesters and forwarders. The total calculated fuel consumption in Finnish CTL operations in 2020 was 126.6 million L, with the calculated CO2eq emissions totalling 334,209 t (i.e. 5.7 kg m−3). Several measures to accelerate fuel and energy efficiency and reduce CO2eq emissions in CTL logging operations are discussed in the paper.

NMR log response prediction from conventional petrophysical logs with XGBoost-PSO framework

A combined approach that exploits both the eXtreme Gradient Boosting (XGBoost) method and the Particle Swarm Optimization (PSO) method was used here to predict the nuclear magnetic resonance (NMR) log parameters such as porosity and permeability from field measurements. Data obtained by NMR are extremely critical for modeling the reservoir behavior and are among the most vital inputs for reservoir simulations. Therefore, developing an intelligent framework that can accurately predict NMR logging response by using conventional, low-cost logging data can be a valuable tool for field development. A number of conventional well logs, such as neutron, density, sonic, caliper, gamma-ray, and resistivity logs, recorded from sixteen wells in an offshore oilfield in Persian Gulf were used in the XGBoost-PSO framework to predict NMR log response. The outputs are the free fluid porosity (CMFF), bound fluid porosity (BFV), permeability (KTIM), and total porosity (TCMR). Based on the results, in terms of prediction accuracy, comparing correlation coefficients, the XGBoost-PSO model performs in the range of 88.5–91.4%. Moreover, the application of PSO in hyperparameter optimization of predicted parameters confirmed at least five percent improvement. Overall, we were able to demonstrate that ordinary conventional logging data can be utilized to obtain more advanced NMR data without performing expensive, time-consuming, and high-risk logging operations to decrease operational costs without compromising the benefits.

Research and Application of Cuttings Flow Prediction Model for Horizontal Well

In the process of horizontal well drilling and logging, real-time and continuous monitoring of returned cuttings is needed to monitor the cleanliness of the hole and reduce complex drilling accidents, such as bit mud bag, wall collapse, stuck drilling, and leakage, which may affect drilling construction and logging operations. However, when the cuttings metering device fails or the acquisition data packet is lost, the cuttings data can be incomplete and discontinuous, which poses a challenge for well cleaning monitoring. In order to solve the problem of incomplete and discontinuous cuttings data caused by instrument failure or collection data packet loss of the cuttings weighing device in operation, this paper studies and compares three cuttings flow measurement prediction models to solve the problem of abnormal data caused by the failure of the cuttings weighing device or collection data packet loss. It provides a reliable means for reducing nonproductive time, monitoring and evaluating borehole cleaning.

Machine Learning Based Recommendation System for Web-Search Learning

Nowadays, e-learning and web-based learning are the most integrated new learning methods in schools, colleges, and higher educational institutions. The recent web-search-based learning methodological approach has helped online users (learners) to search for the required topics from the available online resources. The learners extracted knowledge from textual, video, and image formats through web searching. This research analyzes the learner’s significant attention to searching for the required information online and develops a new recommendation system using machine learning (ML) to perform the web searching. The learner’s navigation and eye movements are recorded using sensors. The proposed model automatically analyzes the learners’ interests while performing online searches and the origin of the acquired and learned information. The ML model maps the text and video contents and obtains a better recommendation. The proposed model analyzes and tracks online resource usage and comprises the following steps: information logging, information processing, and word mapping operations. The learner’s knowledge of the captured online resources using the sensors is analyzed to enhance the response time, selectivity, and sensitivity. On average, the learners spent more hours accessing the video and the textual information and fewer hours accessing the images. The percentage of participants addressing the two different subject quizzes, Q1 and Q2, increased when the learners attempted the quiz after the web search; 43.67% of the learners addressed the quiz Q1 before completing the web search, and 75.92% addressed the quiz Q2 after the web search. The average word counts analysis corresponding to text, videos, overlapping text or video, and comprehensive resources indicates that the proposed model can also apply for a continuous multi sessions online search learning environment. The experimental analysis indicates that better measures are obtained for the proposed recommender using sensors and ML compared with other methods in terms of recall, ranking score, and precision. The proposed model achieves a precision of 27% when the recommendation size becomes 100. The root mean square error (RMSE) lies between 8% and 16% when the number of learners < 500, and the maximum value of RMSE is 21% when the number of learners reaches 1500. The proposed recommendation model achieves better results than the state-of-the-art methods.