Production Period Research Articles

The Effects of Rearing Systems on Incubation, Egg Production and Quality Traits in Pharaoh Quails

This study was conducted to determine the effect of rearing quails in different rearing systems on egg production, egg quality characteristics, and incubation results. The 360 quails were distributed equally to 3 different rearing groups (cage, enriched cage, and floor) in a male:female mixed at the age of 3 weeks. The eggs were individually weighed and recorded one by one daily (5487 eggs) for 3 months. To determine egg quality and incubation characteristics, 750 eggs were broken, and 3284 eggs were incubated, respectively. The results showed that female quail in the floor group have lower body weight at 6 weeks old (177.19 g), and they reached sexual maturity (age of first egg laying) later (65.36 day, P<0.01), The lowest egg production (61.14%) occurred in the floor group during the 3-month egg production period (P<0.05). The lowest average egg weight (9.07 g) was determined in the floor group (P<0.05). It was determined that the eggs of quails raised in the enriched group had a rounder shape index because they have larger widths (P<0.01). While the highest average yolk height (11.24 mm) was determined in the enriched cage group (P<0.01), the highest averages of albumen length (72.41 mm) and lowest averages of yolk index (48.43%) were determined in the cage group (P<0.01). The lowest average values (113.17) in Haugh unit were detected in the floor group (P<0.05). The highest fertility rate (98.44%) was in Floor♂:Cage♀, the highest hatchability of fertile egg rate (94.67%) was obtained from Enriched♂:Cage♀, and the highest hatchability (89.10%) was obtained from Floor♂:Cage♀ pairing (P<0.05). The lowest fertility rate (88.00%) was obtained from the Enriched♂:Floor♀, the lowest hatchability of fertile egg rate (86.01%) was obtained from the Enriched♂:Enriched♀, and the lowest hatchability (75.62%) was obtained from the Enriched♂: Enriched♀ groups. As a result, it has been revealed that the effect of various rearing systems is different on egg production, egg quality traits, and hatching results in quails. Thus, it has been shown that different programs at the rearing period to be applied to the male and female quails can achieve better incubation results and reproductive success.

Effective enhancement of the ability of Monascus pilosus to produce lipid-lowering compound Monacolin K via perturbation of metabolic flux and histone acetylation modification

Monacolin K (MK), also known as lovastatin, is a polyketide compound with the ability to reduce plasma cholesterol levels and many other bio-activities. Red yeast rice (also named Hongqu) rich in MK derived from Monascus fermentation has attracted widespread attention due to its excellent performance in reducing blood lipids. However, industrial Monascus fermentation suffers from the limitations such as low yield of MK, long fermentation period, and susceptibility to contamination. In this study, we firstly blocked the competitive pathway of MK biosynthesis to create polyketide synthase gene pigA (the key gene responsible for the biosynthesis of Monascus azaphilone pigments) deficient strain A1. Then, based on the strategies to increase precursor supply for MK biosynthesis, acetyl-CoA carboxylase gene acc overexpression strains C1 and C2 were constructed with WT and A1 as the parent, respectively. Finally, histone deacetylase gene hos2 overexpression strain H1 was constructed by perturbation of histone acetylation modification. HPLC detection revealed all these four strains significantly increased their abilities to produce MK. After 14 days of solid-state fermentation, the MK yields of strains A1, C1, C2, and H1 reached 2.03 g/100 g, 1.81 g/100 g, 2.45 g/100 g and 2.52 g/100 g, which increased by 28.5 %, 14.7 %, 43.9 % and 36.1 % compared to WT, respectively. RT-qPCR results showed that overexpression of hos2 significantly increased the expression level of almost all genes responsible for MK biosynthesis after 5-day growth. Overall, the abilities of these strains to produce MK has been greatly improved, and MK production period has been shortened to 14 days from 20 days, providing new approaches for efficient production of Hongqu rich in MK.

Ichino periods for CM forms

In both local and global settings, we establish explicit relations between Ichino triple product period and Waldspurger toric periods for CM forms via the theta lifting and the see-saw principle.

A genetic algorithm to solve the production lot-sizing problem with capacity adjustment

When dynamic production capacity is considered in production lot-sizing plans, it becomes very challenging to efficiently determine the optimal production plan. Many papers apply “at most one fractional production period” to develop efficient algorithms, but those algorithms are still time consuming. In this paper, in a special situation where costs are non-speculative, we provide a novel proposal based on “at least one balance period”, in which the products made in this period not only satisfy the demands in this period but also backlogged demands and some demands after this period, to obtain an efficient algorithm. This algorithm complexity is one level lower than the algorithm without non-speculative cost assumptions in the literature regarding the number of periods in their time complexity function. Then, in a general situation, we propose a combination of two complementary algorithms as an efficient heuristic method. Moreover, in the literature, the estimation of computation time complexity in searching for the optimal production plan considers only the number of capacity levels and production periods on theoretical view. However, with numerical experiments, we observe that demand variation could also have significant effects on the computation time in practice.

Hygiene performance rating at farm level - an auditing scheme for evaluation of biosecurity measures’ effect on prevalence of Campylobacter from selected broiler producers

BackgroundPreventing pathogens from entering the broiler premises is the main biosecurity measure at farm level. In conventional broiler production, chickens are kept indoors during the entire production period. Pathogens can enter the broiler-producing unit from sources such as water, equipment, personnel, insects, and rodents. The possible routes must be controlled, and corrective measures applied when necessary. The objective of this study was to (1) develop a hygiene protocol and test the scheme on 30 farms, and (2) compare the results to their Campylobacter-colonised status. A Hygiene Performance Rating protocol at farm level (HPR-F) was developed to systematically review the production to identify risk areas to biosecurity. The HPR-F consists of 13 categories with related questions. For each question, a score was given from 1 to 3, where 1 meant “acceptable”, 2 was “potential for improvements”, and 3 was “not acceptable”. Scores for each question were multiplied with weight factors for hygienic impact and economic consequences describing whether the necessary improvement depends on a significant investment or is a cheap quick-fix and calculated into a percentage where 100% is perfect hygiene. The 30 farms in the study were selected from one county in Norway. The Campylobacter-results for each of the 30 farms in 2019–2021 were given according to rules in the Norwegian Action Plan against Campylobacter faecal sampling on-farm 3–6 days prior to slaughter.ResultsThe overall results from the HPR-F showed that the general hygiene level was high in all farms. The mean total hygiene score was 82% and varied from 70 to 92%. The category Handling dead chicken had the highest hygiene score (93%), and Ventilation had the lowest score (55%). The HPR-F results were compared to the Campylobacter-status for the 30 farms: Campylobacter-negative flocks had slightly higher total scores than Campylobacter-positive flocks (P = 0.19). Among others, the category Outdoor area (vegetation close to the premises’ walls) was identified as the most stable factor in relation to be colonised with Campylobacter.ConclusionsThe HPR-F tested in this research trial provides a tool for veterinarians, advisors, and poultry farmers to improve biosecurity at farm level and enhance the preventive animal health initiatives.

Refined Prediction Method for Production Performance of Deep-Water Turbidite Sandstone Oilfield: A Case Study of AKPO in Niger Delta Basin, West Africa.

Deep-water oilfields frequently employ large or superlarge well spacing, leading to significant production dynamics influenced by reservoir factors. Traditional methodologies often disregard these influences, resulting in poor accuracy. Therefore, an enhanced prediction methodology rooted in reservoir characteristics is proposed. This approach introduces the dynamic relative permeability law as a bridge, capturing macroscopic oil/water movement within the reservoir. For the first time, it integrates production dynamics with key controlling reservoir factors, encompassing reservoir architecture, injection-production connectivity, and reservoir heterogeneity. The results indicate that (1) In deep-water turbidite sandstone fields with ultralarge injector-producer well spacings, the distribution of oil-water movement is primarily influenced by reservoir connectivity and heterogeneity. The injection water sweeping ability coefficient can quantitatively describe the water flooding capacity, with a strong negative correlation between the injection water sweeping ability coefficient and interwell nonconnectivity coefficient and reservoir homogeneity coefficient. This suggests that better reservoir connectivity or weaker heterogeneity results in stronger water flooding capacity, leading to a wider range of water flooding under the same injection volume. (2) For regions with strong water flooding capacity (injection water sweeping ability coefficient 0.30-0.80), the water-free production period is the main production stage, with a focus on improving the planar flooding conditions. For regions with poor water flooding capacity (injection water sweeping ability coefficient 0.00-0.10), the middle and late water-cut periods are the main production stages, with a focus on improving interlayer dynamic differences in the later stages. For regions with moderate water flooding capacity (injection water sweeping ability coefficient 0.10-0.30), the initial focus should be on expanding planar flooding, followed by a focus on improving interlayer dynamic differences in the later stages. (3) The dynamic relative permeability law, capable of comprehensively portraying the reservoir's influence on macroscopic oil/water movement, emerges as a rational choice for production performance prediction in such contexts. Our method can improve the accuracy, compared with traditional method without geographical factors, from 45% to 90% during water-cut rising stage and 31% to 81% during production declining stage. The high prediction accuracy (90%) observed in the AKPO oilfields underscores the method's efficacy in directing on-site optimization and adjustments for the development of deep-water turbidite sandstone oilfields.

Establishment of a protocol for rapidly expanding Epstein–Barr-virus-specific cytotoxic T cells with enhanced cytotoxicity

BackgroundLytic Epstein–Barr virus (EBV) infection plays a major role in the pathogenesis of nasopharyngeal carcinoma (NPC). For patients with recurrent or metastatic NPC and resistant to conventional therapies, adoptive cell therapy using EBV-specific cytotoxic T cells (EBV-CTLs) is a promising option. However, the long production period (around 3 to 4 weeks) and low EBV-CTL purity (approximately 40% of total CD8 T cells) in the cell product limits the application of EBV-CTLs in clinics. Thus, this study aimed to establish a protocol for the rapid production of EBV-CTLs.MethodsBy culturing peripheral blood mononuclear cells (PBMCs) from EBV-seropositive donors with EBV-specific peptides and interleukin (IL)-2, IL-15, and interferon α (IFN-α) for 9 days, we identified that IL-15 can enhance IL-2-mediated CTL activation and significantly increase the yield of CTLs.ResultsWhen IFN-α was used in IL-2/IL-15-mediated CTL production from days 0 to 6, the productivity of EBV-CTLs and EBV-specific cytotoxicity significantly were reinforced relative to EBV-CTLs from IL-2/IL-15 treatment. Additionally, IFN-α-induced production improvement of virus-specific CTLs was not only the case for EBV-CTLs but also for cytomegalovirus-specific CTLs.ConclusionWe established a novel protocol to rapidly expand highly pure EBV-CTLs from PBMCs, which can produce EBV-CTLs in 9 days and does not require feeder cells during cultivation.

Strategic and tactical planning model for the design of perishable product supply chain network in Ethiopia

This article discusses the challenges associated with ensuring food security for a growing global population and emphasizes the critical role of the Agri Fresh Food Supply Chain in addressing these challenges such as mitigating food insecurity and reducing wastes. The economic repercussions of inefficiencies in perishable supply chains impact businesses' profit margins and consumers' access to essential goods. The focus is on the effective management of the complex perishable product supply chains, considering the economic significance of this sector and the need for advanced strategies to optimize the flow of time-sensitive products. The study discusses the limited consideration of product intrinsic characteristics in strategic and tactical planning decisions. The research aims to contribute to supply chain management by proposing a mathematical model (multi echelon, multi product, and multi period) for designing a perishable product supply chain network, considering factors like perishability, quantity discount policy, souring strategies and business continuity. The study explores the impact of these factors on the Agri Fresh Food Supply Chain design and its overall performances. Although the proposed model is designed to be applicable to any country or region, but its capabilities are shown through a real case study in Ethiopia. Results show that a agri-food supply chain design model that considers the intrinsic characteristics of the product, processing capacity level, and quantity discount leads to improved configurations of the food supply chain regardless of adding the associated cost.

Cercospora leaf spot of olive: inoculum production and infections timing throughout the year

Cercospora leaf spot (CLS), caused by Pseudocercospora cladosporioides, is one of the most significant foliar diseases impacting olive production. Over two consecutive years, we investigated the temporal variation of inoculum production and the timing of foliar infections throughout the year on the Arbequina cultivar located in the northwest of Uruguay. Additionally, we examined the influence of meteorological variables in both inoculum production and the occurrence of infections. Two periods characterized by substantially higher spore production were identified, one during late spring to early summer and the other during autumn, both favored by temperatures of 20-25 °C and relative humidity between 80 and 95%. The lowest production was registered in winter explained by frequent days with temperatures below 10 °C. Infections occurred throughout the year, with a significant decrease during the early spring, probably due to a low spore available in the field and the less susceptibility of young leaves to be infected. These findings will help growers design effective management strategies focusing on the highest inoculum production periods, especially in autumn when the infections are more abundant.

Geomechanics Modeling of Strain-Based Pressure Estimates: Insights from Distributed Fiber Optic Strain Measurements

Summary Rayleigh frequency shift distributed strain sensing (RFS-DSS) has been demonstrated as a potential technology for characterizing fracture geometries and optimizing the completion design in unconventional reservoirs. The combination of RFS-DSS strain and pressure gauge measurements has been reported recently in field applications (Dhuldhoya and Friehauf 2022; Haustveit and Haffener 2023) to characterize conductive fracture dimensions and production profiles. Haustveit and Haffener (2023) demonstrated a novel technique that uses RFS-DSS strain change during production, measured from a far-field observation well, to monitor the drain profile of a horizontal multistage well. The strain change and pressure change were strongly related during production, and this relationship was applied to continuously estimate pressure drawdown along the full length of the well. However, the sensitivity or influencing factors of the relationship between strain change and pressure change along the fiber are not yet fully understood. Therefore, the main objective of this study is to investigate the relationship between strain change and pressure change under various fractured reservoir conditions and provide guidelines for better utilizing this novel strain-pressure relationship to estimate conductive fractures and pressure profiles. We use a coupled geomechanics and fluid flow model to simulate the strain and pressure changes in the near-well and far-field regions during stable production and shut-in periods. A linear relationship is used to fit the strain change and pressure change data obtained from both producing and monitoring wells. We analyze the impact of various fracture properties [size and permeability of the stimulated reservoir volume (SRV) around fractures, fracture conductivity, fracture area, and skin factor] on the linear relationship based on the R2 value and fitting error. The relationship between the strain change and pressure change during the stable production obtained by our numerical study is consistent with the field measurements. The slope of strain change vs. pressure change during one day of production is significantly influenced by fracture properties. Overall, the monitoring well shows a stronger linear relationship than the producing well during both stable production and shut-in periods. A better linear relationship between the strain change and pressure change is associated with a larger fracture conductivity or larger fracture spacing scenario on both producing and monitoring wells during the stable production period. The cluster spacing affects the linear relationship between strain and pressure change during rock deformation. When cluster spacing is reduced, the nonlocal effect of deformation becomes more pronounced, resulting in a weaker linear relationship. During the shut-in period, the monitoring well exhibits a stronger linear relationship with a high R2 value and small fitting error compared to the producing well. The linear relationship obtained during the shut-in period is less reliable for the producing well. In cases of homogeneous fractures, where the fracture properties are uniform, the strain change and pressure change are similar, except for two outer fractures. This study provides a better understanding of the relationship between strain change and pressure change measured in the near-well and far-field regions during stable production and shut-in periods. The results of our study also demonstrate the potential for utilizing the RFS-DSS strain measurement to characterize the effective fracture and drainage dimensions.

"Witzelsucht". On the introduction and meaning of the term by Hermann Oppenheim in 1890 and its distinction from "moria"

Hermann Oppenheim (1858-1919) was a German neurologist without an academic career, who in his productive period around 1900 made aname for himself during his lifetime as amajor player in the history of German neurology with his many contributions to multiple sclerosis, syphilis and the controversial study of traumatic neurosis; however, it is almost unknown that in 1890 he introduced the term "witzelsucht", which is still used internationally today. Moritz Jastrowitz dealt with behavioral abnormalities due to frontal brain injuries 1year earlier and used the term "moria" for aform of mental disorder associated with akind of childish behavior and inappropriate jocularity. Oppenheim was critical of this and differentiated his "witzelsucht" from this. With this term he wanted to describe humoristic feeble-mindedness in a much narrower sense, which stands in striking contrast to the usual symptoms in cases of cerebral tumors. Oppenheim recognized the frontal brain, particularly the right brain, to be an important functional unit for humorous behavior. Modern research has confirmed that the processing of humor requires a complex interaction of multiple brain regions. Damage to the right frontal lobe or to connecting structures can lead to the disorder "witzelsucht". Whether asimultaneous damage to the left hemisphere must be present or if this is dependent on the individual dominant hemisphere, needs further research.

Tingkat Kepuasan Petani Terhadap Penggunaan Pupuk Hayati Boc-Srf dan Pupuk Hayati X dalam Meningkatkan Produksi Cabai Merah

Red chilli is a plant that has always been the subject of discussion because it can cause inflation in Indonesia. Even though demand is high, the lack of goods causes prices to soar. One effort to increase red chilli productivity is the use of fertilizer. The Center for the Study and Application of Technology (BPPT) has produced superior biological fertilizers, namely BOC-SRF Biological Fertilizers, which farmers use on red chilli plants. Farmers as consumers certainly feel satisfied or not after using this fertilizer or other biological fertilizers; therefore, it is necessary to research the level of satisfaction of farmers regarding the use of BOC-SRF Biofertilizer and Biological Fertilizer Hayati BOC-SRF with Hayati X in Sukatani Village, Pacet District, Cianjur Regency with 40 farmers as respondents. The analysis method uses the Customers Satisfaction Index (CSI), Important Performance Analysis (IPA) and Diagonal Analysis (Suharjo Split). As a result, farmers were very satisfied with the performance of BOC-SRF biofertilizer (CSI: 81%), while farmers using X biofertilizer were satisfied with an index value of 74.4%. The attribute that is the main priority but performs poorly when using BOC-SRF biological fertilizer is the "productive period". In contrast, for X biological fertilizer, it is the "productive period and production yield". The analysis of service efficiency levels showed that over-service occurred in the HPT resistance attribute of BOC-SRF biofertilizer, while other attributes experienced under-service. At the level of biofertilizer service efficiency X, all attributes are experienced under service.

Lessons and experiences of the second period of international production in Russia

Lessons and experiences of the second period of international production in Russia

Pemberdayaan Kemitraan Masyarakat untuk Meningkatkan Kualitas Proses Produksi dan Pemasaran Jamur Tiram pada Kelompok Tani Trah Tiram Mandiri di Parungkuda

Community Partnership Empowerment (CPE) as the topic of community service activities in the Community Based Empowerment scheme with partners, namely the Mandiri Tiram Farmers group located in Parungkuda. The objectives of CPE are (1) Providing solutions to problem solving aspects of production using technology to increase partner income by 10%. (2) Assistance in developing marketing strategies by utilizing communication and information technology to expand the market. Implementation of activities through the stages of socialization, discussion, asset handover, mentoring and evaluation. The results of PKM activities can provide solutions in the production aspect by providing assistance with sterilization process equipment to improve the quality of making mushroom seeds (baglog). Press machine assistance to maintain consistent baglog density and increase production capacity. Assistance activities in developing marketing strategies by providing knowledge and skills in the use of information communication technology, packaging label designs and processed mushroom food products. The output of CPE activities is an increase in sales turnover of oyster mushrooms from Rp. 19,800,000/month to Rp. 21,780,000/month or 10% for 1 production period can be achieved successfully by applying technology in the production process of making mushroom seeds.

Decoding Capua’s roof terracotta: A multi-analytical study of the Fondo Patturelli sanctuary and Alveo Marotta furnace (6th century BCE – 1st century BCE)

The main focus of this study was to examine 25 samples of archaeological ceramic materials currently preserved in the Archaeological Museum of the Ancient Capua and Mitreo investigated in the framework of an international project. These samples primarily consist of architectural terracotta from the Fondo Patturelli extra-urban sanctuary, as well as architectural terracotta, pottery and waste material from the nearby Alveo Marotta furnace.To investigate these artifacts, a multi-analytical mineralogical-petrographic approach was performed. Thin section observations revealed that almost all samples exhibit a coarse-grained paste. The fragments were categorized into three petrographic groups based on the type and quantity of temper, which is mostly composed of volcanic grains. They include lithics and juvenile fragments (obsidians and pumices) ascribed to the products of the major Campanian eruptions as detected via FESEM-EDS. Bulk chemical analyses (WD-XRF) show that almost all samples form a homogeneous group made with Ca-rich clayey raw materials, also including three wastes of tiles from the Alveo Marotta. By contrast, other two wastes from Alveo Marotta were produced with Ca-poor clay suggesting the use of a different raw material.From a technological point of view the samples are characterized by a thermal range that varies from 750 to 900 °C, notably different between the earlier and later production periods, with the former fired at lower temperatures.

Development of farming systems in the Prienisey Siberia

The paper presents the results of research conducted to assess the development of farming systems in the Prienisei Siberia over a long period of time as a basis for identifying factors determining crop productivity, and as an information basis for forecasting crop yields by 2030. The work provides information covering more than two hundred years of land practice in the Prienisei Siberia. It was found that in all the periods of agricultural production, each of which corresponds to a certain farming system, the trend of yield change was positive. Each successive period was shorter than the previous one, with yields increasing significantly. The period of extensive technologies application in farming lasted more than 140 years. At this time, yields increased by 0.0018 t/ha per year. The period of use of the ordinal (low-intensity) farming system lasted approximately 50 years. The yields then increased by 0.0204 t/ha per year. During the period of intensification of the farming system, which took about 30 years, the yields increased by 0.0212 t/ha per year and reached about 2.1 t/ha by the end of the period. The period of formation of high-intensity farming system is the shortest, characterized by the highest productivity growth rates – 0.0639 t/ha per year. If this trend is maintained, the long-term average yield of 3.0–3.5 t/ha will be reached approximately by 2030. For each soil-climatic zone it is advisable to have its own, original farming system, developed taking into account soil-agrochemical properties, landscape and climatic peculiarities, characterized by more in-depth differentiation of individual working area. It should present digital technologies using modern electronic means of informatization, geoinformation systems, remote methods and means of technological processes control, aerial and space methods of agro-ecosystems diagnostics.

Sustainable Electrosynthesis of N,N-Dimethylformamide via Relay Catalysis on Synergistic Active Sites.

Electrified synthesis of high-value organonitrogen chemicals from low-cost carbon- and nitrogen-based feedstocks offers an economically and environmentally appealing alternative to traditional thermocatalytic methods. However, the intricate electrochemical reactions at electrode surfaces pose significant challenges in controlling selectivity and activity, especially for producing complex substances such as N,N-dimethylformamide (DMF). Herein, we tackle this challenge by developing relay catalysis for efficient DMF production using a composite WO2-NiOOH/Ni catalyst with two distinctive active sites. Specifically, WO2 selectively promotes dimethylamine (DMA) electrooxidation to produce strongly surface-bound (CH3)2N*, while nearby NiOOH facilitates methanol electrooxidation to yield more weakly bound *CHO. The disparity in binding energetics of the key C- and N-intermediates expedites C-N coupling at the WO2-NiOOH interface. In situ infrared spectroscopy with isotope-labeling experiments, quasi-in situ electron paramagnetic resonance trapping experiments, and electrochemical operating experiments revealed the C-N coupling mechanism and enhanced DMF-synthesis selectivity and activity. In situ X-ray absorption spectroscopy (XAS) and postreaction transmission electron microscopy (TEM) studies verified the stability of WO2-NiOOH/Ni during extended electrochemical operation. A Faradaic efficiency of ∼50% and a production rate of 438 μmol cm-2 h-1 were achieved at an industrially relevant current density of 100 mA cm-2 over an 80 h DMF production period. This study introduces a new paradigm for developing electrothermo relay catalysis for the sustainable and efficient synthesis of valuable organic chemicals with industrial potential.

Experimental investigation on cyclic steam stimulation assisted modified THAI to enhance oil recovery in steam-treated heavy oil

Steam injection is well accepted as a main method for heavy oil reservoirs. Currently, most heavy oil reservoirs have reached the late stage of steam treatment and encountered various challenges thus alternative methods are needed to develop the remaining oil. CSS1 Assisted Modified THAI2 (CSSAMT) is proposed to be an effective follow-up method in heavy oil reservoirs treated by steam. CSSAMT combines the benefits of ISC3 and steam, with steam acting as a protective agent for production wells threatened by combustion as well as a restrainer for oxygen breakthrough. A 3-dimensional physical model was conducted for the experiment to simulate the process and investigate the mechanism. The result demonstrates the feasibility of the CSSAMT process with a high oxygen availability of 99.8% and an average apparent H/C ratio of 0.71, achieving an oil recovery factor of 44.01%. Optimal steam injection parameters were determined as a 0.03 T (dimensionless time)-soak period followed by a 0.06 T production period. Additionally, oil upgrading results were quantitatively described through the carbon number variations, and a prediction formula correlating the sweep efficiency and the carbon number variations was proposed, showing a correlation coefficient of 0.9.

Characterization of the Dominant Stages at Which Gas Flaring Is Introduced: Impacts and Policy Options to Ameliorate Them

Information on associated gas flaring in the Niger Delta is analyzed to characterize the various stages in the lifecycle of an oil exploration and production facility through which gas flaring is introduced into an area, leading to ecological, health, and economic impacts, and possible policies and implementation strategies for the reduction of the flared gas are offered. Gas flaring is currently occurring at a rate of 5318 million m3 per year in the Niger Delta region. The impacts of gas flaring on the ecological, human, and economic systems include poor air quality, acid rain, and soil degradation. Other impacts include decreased crop yield, increased incidences of respiratory diseases amongst inhabitants in the area, and losses of billions of USD yearly in economic costs. Three dominant stages in the introduction of gas flaring are characterized in this study, using the concept of the management of the invasion of non-native species into an ecosystem and it is determined that the cheapest method of minimizing gas flaring is to incorporate mitigation measures during the design stage of the oil exploration/production facility, rather than after flaring has commenced, as is the common emphasis. During the early periods of oil production, gas flaring is largely localized, and the gas utilization measures can still be implemented to good effect. However, once the facility is established, gas flaring becomes pervasive, stretching kilometers beyond the flare points. Current policies like the imposition of flare-out years on the oil producers have helped, but they have been insufficient as the intensity of gas flaring in the region continues at double the average global levels. Working with relevant stakeholders, a realistic flare-out deadline should be agreed upon, clear and specific gas flaring legislation should be drawn up that includes measures to mitigate gas flaring for each proposed oil facility, and proper data collection and management services would enable the implementation of the policies to be based on robust evidence. These policies would shift the costs of gas flaring away from the inhabitants of the region back to the operators of the facilities that are the sources of the flares.

Numerical Simulation of Gas Production Behavior Using Radial Lateral Well and Horizontal Snake Well Depressurization Mining of Hydrate Reservoir in the Shenhu Sea Area of the South China Sea

Improving the production capacity of natural gas hydrates (NGHs) is crucial for their commercial development. Based on the data of the first on-site testing production of NGHs in the Shenhu Sea area, numerical methods were used to analyze the production behavior of radial lateral well (RLW) and horizontal snake well (HSW) with different completion lengths when they deployed at different layers of the Class-1 type hydrate reservoir (with a fixed pressure difference of 6 MPa and continuous production for 360 days). The results indicate that compared with the single vertical well production, RLW and HSW can effectively increase production capacity by enlarging drainage area and the productivity is directly proportional to the total completion length. The RLW and HSW deployed at the three-phase layer (TPL) have optimal mining performance within a 360-day production period. Different to the previous research findings, during a short-term production period of 360 days, regardless of the deployment layer, the overall production capacity of HSW is better than RLW’s. The total gas production of HSW-2 circles well type is about four times that of a single vertical well, reaching 1.554 × 107 ST m3. Moreover, the HSW-1 lateral well type stands out with an average Qg of 3.63 × 104 ST m3/d and a specific production index J of 16.93; it has the highest J-index among all well types, which means the best mining efficiency. It is recommended to choose the HSW-1 circle well type, if the coiled tubing drilling technique is used for on-site testing production of NGHs in the future. The research results provide insights into the potential applications of RLW and HSW in this sea area.