Increase Recovery Efficiency Research Articles

Enhancement of Tricyclazole Analysis Efficiency in Rice Samples Using an Improved QuEChERS and Its Application in Residue: A Study from Unmanned Arial Spraying

Enhancements to the analytical method for the determination of tricyclazole in rice samples have been applied to monitor residues during unmanned aerial spraying. The acetonitrile extraction technique QuEChERS was improved by the incorporation of ethyl acetate and 0.1% formic acid, which significantly elevated the recovery rates. Furthermore, the purification process was refined by integrating both primary–secondary amine (PSA) and C18 in the dSPE method, achieving a substantial improvement in reducing matrix effects (MEs) and increasing recovery efficiency. The optimized method demonstrated an impressive % ME value at −3.1%, with a limit of quantitation (LOQ) established at 0.01 mg/kg, and recovery rates between 94.7 and 95.6% at 0.01, 0.1, and 2 mg/kg. Using two types of adjuvants (stickers) during multi-copter spraying markedly improved the initial tricyclazole deposition on rice panicles, with residue levels initially increasing from 0.35 mg/kg to between 0.68 and 1.60 mg/kg. Residues in hulled rice at harvest (10 days post-application) remained well below the maximum residue limit (MRL) of 0.7 mg/kg, ranging from 0.02 to 0.11 mg/kg, thus affirming the safety and efficacy of adjuvants in residue management.

A comprehensive review direct methods to overcome the limitations of gas injection during the EOR process

Among the Enhanced Oil Recovery (EOR) methods, gas-based EOR methods are very popular all over the world. The gas injection has a high ability to increase microscopic sweep efficiency and can increase production efficiency well. However, it should be noted that in addition to all the advantages of these methods, they have disadvantages such as damage due to asphaltene deposition, unfavorable mobility ratio, and reduced efficiency of macroscopic displacement. In this paper, the gas injection process and its challenges were investigated. Then the overcoming methods of these challenges were investigated. To inhibit asphaltene deposition during gas injection, the use of nanoparticles was proposed, which were examined in two categories: liquid-soluble and gas-soluble, and the limitations of each were examined. Various methods were used to overcome the problem of unfavorable mobility ratio and their advantages and disadvantages were discussed. Gas-phase modification has the potential to reduce the challenges and limitations of direct gas injection and significantly increase recovery efficiency. In the first part, the introduction of gas injection and the enhanced oil recovery mechanisms during gas injection were mentioned. In the next part, the challenges of gas injection, which included unfavorable mobility ratio and asphaltene deposition, were investigated. In the third step, gas-phase mobility control methods investigate, emphasizing thickeners, thickening mechanisms, and field applications of mobility control methods. In the last part, to investigate the effect of nanoparticles on asphaltene deposition and reducing the minimum miscible pressure in two main subsets: 1- use of nanoparticles indirectly to prevent asphaltene deposition and reduce surface tension and 2- use of nanoparticles as a direct asphaltene inhibitor and Reduce MMP of the gas phase in crude oil was investigated.

Comprehensive assessment of the agronomic, environmental and economic benefits effects of nitrogen fertigation management on maize in Northeast China

ABSTRACT Seeking economical, efficient and environmentally friendly nitrogen fertigation management strategies is extremely important for sustainable maize production. A two-year field experiment was conducted to investigate the effects of four nitrogen fertilization methods N0: no nitrogen application; FP: applying 234 kg N ha−1 at sowing; NF1: applying 210 kg N ha−1, 50% N at sowing and 50% N fertigation at the V8 stage; and NF4: applying 210 kg N ha−1 sowing: 30%, fertigation at V8: 20%, V12: 20%, R1: 20%, R3: 10% on maize yield, nitrogen and water use efficiency, economic benefits and the environmental assessment in Northeast China. The results showed that compared with the FP treatment, the NF1 and NF4 treatments significantly increased maize yield by 13.2% and 18.6%, increased recovery efficiency of nitrogen (REN) by 38.6% and 68.4%, agronomic nitrogen efficiency (AEN) by 58.6% and 78.2%, water use efficiency (WUE) by 23.8% and 26.9%, and net income by 16.1% and 25.7%, respectively. Additionally, the treatments reduced the apparent nitrogen loss by 69.5% and 96.1%, nitrogen footprint by 34.4% and 37.4% and carbon footprint by 17.0% and 20.8%, respectively. The yield, REN and net income of NF4 were significantly higher than those of NF1 by 4.8%, 21.6% and 8.3%, respectively, and the nitrogen and carbon footprints of NF4 were significantly lower than those of NF1 by 4.6% and 4.6%, respectively. The NF4 treatment was recommended as an effective method for improving yield and net income and reducing the environmental cost while achieving sustainable maize production.

Numerical Simulation Study on Parameter Optimization of In-depth Fluid Diversion in Low-permeability Fractured Reservoir

Daqing Chaoyanggou Oil Field is a low-permeability fractured oil reservoir that has entered into the middle and high water-cut periods of waterflooding extraction. Now, the moisture content is 74.88% and the injected water flows along fractures. The moisture content of oil wells increases quickly, accompanied with relatively serious invalid waterflooding. The in-depth fluid diversion can be used to exploit residual oil in substrate effectively and thereby increase recovery efficiency of the low-permeability fractured oil reservoir. In this study, parameters of in-depth fluid diversion in low-permeability fractured reservoirs can be optimized by numerical simulation method. According to geologic characteristics and fracture development situations in the study area, a geologic model of the study area was constructed. A historical fitting of exploitation indexes was carried out to optimize the dosage, injection rate and injection time of control-displacement agent during in-depth fluid diversion. Results demonstrated that the optimal dosage, the optimal injection rate and the optimal injection time of the control-displacement agent were 0.1 ∼ 0.15PV, 0.03 ∼ 0.04PV/a and about 70% of comprehensive moisture content, respectively. This study can provide reference to residual oil recovery in low-permeability fractured reservoirs during middle and high water-cut periods.

Enhanced Anaerobic Digestion Using Conductive Materials through Mediation of Direct Microbial Interspecies Electron Transfer: A Review

The anaerobic digestion (AD) of organic matter is susceptible to the challenges posed by low-speed electron transfer between microorganisms and the limitation of low hydrogen partial pressure, resulting in low methane recovery efficiency and poor system stability. Numerous studies in recent years have shown that a variety of conductive materials can significantly increase the interspecies electron transfer (IET) rate, optimize the structure and function of anaerobic microbial communities, improve methane yield, and promote system stability by mediating the direct interspecies electron transfer (DIET) of reciprocal microorganisms. In this study, on the basis of investigating the IET mechanism of methanogenic microorganisms in the AD of organic matter, the effects of carbon-based conductive materials (activated carbon, biochar, carbon cloth, carbon fiber, graphite, graphite felt, graphene, and carbon nanotubes) and iron-based conductive materials (magnetite, Fe3O4, hematite, Fe2O3, goethite, and zero-valent iron) on AD performance and microbial community using DIET are reviewed. Future research should focus on establishing an evaluation system, identifying flora with DIET potential, and finding methods for engineering applications that increase recovery efficiency and reveal the principle of conductive materials to mediate DIET.

Self‐stabilizing maintenance process in plant communities of alpine meadows under different grazing intensities

AbstractBackgroundsGrazing prohibition and reduced grazing intensity, as two important “vegetation close‐to‐nature recovery” methods, have been suggested as economical and effective technologies for enhancing forage production. However, numerous studies have found that the yield of forage could be increased by removing or reducing grazing in a short time in some steady stage of alpine Kobresia meadows, but not in others. To reveal the mechanism behind this phenomenon, we proposed a series of experiments.MethodsWe monitored the plant and soil characteristics in the key steady stages of Kobresia meadows under reduced and prohibited grazing conditions in the same geographic and climatic environments in the northeastern Qinghai‐Tibet Plateau for 6 years. We estimated the relationships between the plant community and soil nutrients and obtained the following results.ResultsAll measured variables were positively correlated with each other. The plant community structure had higher path coefficients to aboveground biomass, soil organic matter, total nitrogen, and nitrate nitrogen than to other factors. The plant community structure played an important role in response to grazing intensity. Different plant functional groups (PFGs) had different responses to grazing intensity, which led to plant community re‐establishment or re‐organization under different grazing intensities. Poaceae and Kobresia were more sensitive to grazing intensity than other PFGs, and the ratio of Kobresia biomass (including Kobresia humilis and Kobresia pygmaea) to the total biomass of Poaceae and Kobresia could be used as an indicator of regime shifts within plant communities. With Kobresia pygmaea as the dominant species, the prohibition of grazing was not an efficient approach to increase the yield in the steady stages because this treatment needed more time to recover aboveground biomass. If Poaceae is the dominant PFG, grazing should only be prohibited for 3 years in the steady stages because the aboveground biomass will decrease if grazing is prohibited for more than 3 years.ConclusionsTherefore, the different steady stages of alpine meadows require different recovery methods to increase recovery efficiency and speed.

In Situ Electroplating of Ir@Carbon Cloth as High-Performance Selective Oxygen Evolution Reaction Catalyst for Direct Electrolytic Recovery of Lead

The hydrometallurgical technology provides an efficient and sustainable green lead recovery process from lead acid batteries. Methanesulfonic acid has been widely considered as a green solvent for lead electrolytic recovery. However, the competitive precipitation of PbO2 at anode and higher overpotential for OER limit the lead recovery efficiency. In this work, an anodic oxygen evolution reaction (OER) catalyst with a low Ir mass fraction of 7.2% is obtained by electroplating iridium on carbon cloth (CC), exhibiting a lower overpotential of 256 mV, longer lifetime of 10 h, and better stability in the 0.5 M MSA solution. When CC-Ir is used as an anodic catalyst for lead recovery in the lead methanesulfonate electrolyte, only a lesser Pb precipitation product with Pb atom mass fraction of 1.42% is found after electrolysis of 10 h, demonstrating the suppression effect of CC-Ir for a PbO2 side reaction. This work proves that the anodic catalyst plays an important role in the lead electrolytic recovery process, which can inhibit the side reaction, reduce the energy consumption, and increase recovery efficiency.

Evaluation of the Agronomic Efficiency of Azospirillum brasilense Strains Ab-V5 and Ab-V6 in Flood-Irrigated Rice

The rational use of nitrogen fertilization is fundamental, not only to increase recovery efficiency, but also to increase crop productivity and reduce the production costs and risks of environmental impacts. In the State of Rio Grande do Sul in Brazil, irrigated rice productivity can surpass 8 tonne·ha−1 as a result of the technification of the crop and favorable environmental conditions, yet there is great variability in the agronomic efficiency of chemical nitrogen fertilizers, which rarely exceed 50% of the applied dose. Biological nitrogen fixation is one of the technological alternatives for reducing the use of nitrogen in this crop. In this study, the agronomic efficiency of Azospirillum brasilense strains Ab-V5 and Ab-V6 in terms of biological nitrogen fixation in flood-irrigated rice cultivars in a lowland agroecosystem was evaluated through five field experiments. A. brasilense combined with reduced nitrogen fertilization (reduction of 30 kg N·ha−1) increased the dry mass of the aerial part of rice plants by 3.2%, and promoted an increase in N concentration in stems and leaves and in the N content exported by grains by 43% and 27.5%, respectively, in relation to the absence of N and inoculant, and promoted an average increase of 30% in rice production.

Preliminary evaluation of different methods to detect and quantify Taenia eggs in sludge and water samples: A spiking experiment to assess recovery efficiency

An improved understanding of the environmental transmission of Taenia spp. is key to control of the parasite. Methods to detect and quantify Taenia eggs in different environmental matrices, including sludge and water, currently lack performance validation with regard to the recovery efficiency and process ease of use. Therefore, this study aimed to assess the recovery efficiency and process duration of commonly used methods for the detection of Taenia eggs in sludge and water samples. Ten detection methods for Taenia spp. eggs were selected from a systematic review. Sludge and water samples were spiked with a high dose of Taenia saginata eggs, i.e., around 200 eggs/g sludge and 50 eggs/ml water, and were tested using five methods each. The two methods with the highest egg recovery efficiencies were selected per matrix for assessment with a lower spiking dose, i.e., 4 eggs/g sludge and 1 egg/ml water. Each time five replicates were used. Recovery efficiency was defined as the proportion of the number of eggs recovered to the total number of eggs spiked. Using the high spiking dose, all samples tested positive for all the methods. The mean egg recovery efficiency varied from 4% to 69% for sludge samples and from 3% to 68% for water samples. Using the lower spiking dose, one of the methods performed on sludge samples was able to detect all replicates, whereas only one replicate was positive using the other method. For water, all low dose samples tested positive using both methods. In conclusion, most methods performed inadequately in recovering Taenia eggs from sludge and water, with half of the methods performed on the high dose samples having a mean egg recovery efficiency of approximately 10% or less. The assessed recovery methods were generally time-consuming and labourious. A more thorough validation of existing recovery methods and improvement of method protocols to increase recovery efficiency is thus urgently needed.

Effect of impact – reflective super – speed grinding on TanRai Aluminum hydroxide characteristics and dissolution efficiency in acid and base media

Study on different characteristics of TanRai aluminum hydroxide dissolution process in acid and base media were carried out on unactivated and activated samples using 3000rpm centrifugal grinding method under other conditions. The experimental results showed that the centrifugal grinding process did not change the solid phase structure (Gibbsite), and the specific surface of the sample was increased by 1.5 times, average particle size was increased by 10 times, the surface morphology during process of TanRai aluminum hydroxide dissolution were different. In the case of the process of Al(OH)3 dissolution in NaOH media, the corrosion reaction occurs on the all surface of the particle. It goes deep and accesses into the particle. The specific surface might be increased by 10 times in reaction processing, so the grinding did not increase recovery efficiency. In case of dissolution Al(OH)3 in HCl media, the reaction occurs on surface particle so the grinding effects to dissolution recovery that increasing from 2 to 5 times.

An emergency response system by dynamic simulation and enhanced particle swarm optimization and application for a marine oil spill accident

An emergency response system is important to protect the public and the environment and mitigate the negative effects from major accidents or natural disasters. It helps minimize time and losses by optimizing response operations and use of resources. Marine oil spills, as a typical accident, can cause significant, long-term and adverse impacts on ecological, social and economic systems. An efficient response system can significantly reduce both overall response time and cost especially when dealing with a large-scale spill. This paper proposed an emergency response system based on dynamic process simulation and system optimization modeling. This was achieved by the development of an enhanced particle swarm optimization (ME-PSO) algorithm with outstanding convergence performance and low computation cost characteristics which integrated multi-agent theory and evolutionary population dynamics. The performance was evaluated using various PSO algorithms with 13 benchmark functions under 48 parameter combinations. A case study on a representative marine oil spill was conducted to demonstrate the proposed methodology and its value in supporting emergency response decision-making. Allocation and deployment of responses from multiple response centers were optimized to save time and increase recovery efficiency with the process simulations of resource dispatch, oil weathering and oil removal. The research not only contributed to emergency decision making through an integrated, dynamic and simulation-optimization coupling approach but also provided emergency responders a powerful tool to improve their response capabilities in dealing with emergencies such as marine oil spills.

Evaluation of a modified method for the detection of Cryptosporidium oocysts on spinach leaves

Despite the infection risk associated with the consumption of contaminated food, techniques for recovering and detecting Cryptosporidium oocysts from fruit and vegetables are generally inadequate due to the variable recovery efficiencies and high reagent costs, such as those presented by ISO 18744:2016 “Microbiology of the food chain -Detection and enumeration of Cryptosporidium and Giardia in fresh leafy green vegetables and berry fruits”. Although an improved method for recovering these parasites from Iceberg lettuce, which reported increased recovery efficiency as well as lower costs, has been published, it appears to have limitations for the recovery of Cryptosporidium from saponin-rich leaves such as spinach (Spinacia oleraceae), which have previously been implicated in Cryptosporidium parvum outbreaks. In this study, we refined the method to improve its use with these more challenging samples. The use of alkaline elution buffer (1 M glycine) of different pH values was evaluated for their effectiveness in removing C. parvum from spinach leaves. The refinement of Utaaker's method showed, from spinach leaves inoculated with 100 oocysts, an increased oocyst recovery rate with an overall mean recovery rate of 33.79% ± 2.82%. The emergence of parasitic foodborne illnesses and outbreaks associated with the consumption of fresh produce demonstrates the need for the development of an optimal recovery process for parasites from suspected foods. Results showed that refinement of existing protocols could improve the retrieval of Cryptosporidium oocysts from these more challenging leafy greens.

Displacement of Oil in a Porous Medium on Diphasic Flow by Water Injection

The purpose of this article is to show the role and influence of fluid injection, porosity on two-phase flows in porous media for the purpose of improving and increasing recovery efficiency assisted by oil. An experimental study was carried out in porous media, it is a plexiglass cylinder filled with sands saturated with crude oil. Pressure drop and data processing for two-phase flow are measured and processed using a differential pressure sensor connected to an acquisition computer. It thus makes it possible to determine the pressure difference between the inlet and the outlet of the porous medium over time. In this experiment, the flow rates at the inlet and the outlet of the porous medium were measured as a function of time using a flow rate and a pump. To describe these flows we will use Darcy’s model.

Coupling Smart Seawater Flooding and CO2 Flooding for Sandstone Reservoirs: Smart Seawater Alternating CO2 Flooding (SMSW-AGF)

Petroleum engineers continue to seek cost-effective improved oil recovery (IOR) methods to increase recovery efficiency, especially in heavy oil accumulations. Currently, smart water, low-salinity ...

Energy, Environment, and Social Development: The Role of R&D in Energy Sustainability - Global Oil and Gas Supply Security and Future Energy Mix

President's column A key component of sustainability is human lifestyle—meeting not just the basics, but for all people to have the opportunity to grow, develop, and prosper. Unquestionably, access to energy is a key component of achieving this goal. Having an adequate, reliable, affordable, environmentally-cleaner and uninterrupted supply of energy is crucial. Despite the calls to immediately cease using fossil fuels, hydrocarbon resources are essential to support the global economy. We cannot achieve a sustainable world in the long term without access to oil and gas. Currently, more than 50% of world energy demand is met by oil and gas. The difficult and yet-to-be-answered questions in the energy industry are the timing of oil and gas depletion and the energy mix afterward. Will oil remain as the primary source of energy at the end of this century, especially in the transportation sector which currently consumes from 75 to 80% of the oil produced? Will gas remain as a primary source of energy for power generation and petrochemicals by the end of this century? Even with renewable energy growing by 400% or more, when will there be enough of these sources to replace oil and gas? Will they be practical for transportation? No one disagrees that oil and gas are depletable energy sources, and that we must find other sources of energy to replace them if mankind’s lifestyle on Earth is to be maintained or improved for hundreds, or I may say, thousands of years to come. However, knowing precisely when this will happen is quite challenging. The oil and gas industry long ago embraced the challenge of finding and producing enough resources to meet growing world demand. Replacing what is produced each year isn’t enough; as demand grows, production capacity must grow, which means discovering more resources. We’ve met that challenge. How? By making enormous investments in research and development (R&D). There is absolutely no doubt that the last few decades’ R&D efforts have reduced uncertainties on the exploration side and have increased recovery efficiency. Thanks to newly developed technologies, fields that were not economically feasible before are now being developed. We’ve learned how to economically and safely produce tight and unconventional resources, and those in hostile environments. All of this has resulted in significant reserves addition and recovery increases.

“NEW” resource recovery from wastewater using bioelectrochemical systems: Moving forward with functions

Bioelectrochemical systems (BES) have been extensively studied for resource recovery from wastewater. By taking advantage of interactions between microorganisms and electrodes, BES can accomplish wastewater treatment while simultaneously recovering various resources including nutrients, energy and water (“NEW”). Despite much progress in laboratory studies, BES have not been advanced to practical applications. This paper aims to provide some subjective opinions and a concise discussion of several key challenges in BES-based resource recovery and help identify the potential application niches that may guide further technological development. In addition to further increasing recovery efficiency, it is also important to have more focus on the applications of the recovered resources such as how to use the harvested electricity and gaseous energy and how to separate the recovered nutrients in an energy-efficient way. A change in mindset for energy performance of BES is necessary to understand overall energy production and consumption. Scaling up BES can go through laboratory scale, transitional scale, and then pilot scale. Using functions as driving forces for BES research and development will better guide the investment of efforts.

Narrowing yield gaps and increasing nutrient use efficiencies using the Nutrient Expert system for maize in Northeast China

A science-based, reliable, and feasible fertilizer recommendation method is required to respond to the low nutrient use efficiency caused by inappropriate fertilization practices. Soil test-based fertilizer recommendations are difficult to use for smallholder farms because of constraints such as access, cost and timeliness in multiple cropping systems. In this study, we combined on-farm experiments from 2012 to 2014 in 20 farmers’ fields on spring maize in Northeast China with a simulation model (Hybrid Maize model), to test the continual performance in agronomic, economic and environmental aspects of the Nutrient Expert for Hybrid Maize decision support system. Six treatments were set as follows: Nutrient Expert (NE), farmers’ practice (FP), soil testing (OPTS) and nitrogen (N), phosphorus (P), and potassium (K) omission treatments based on NE. We estimated yield gaps as the difference between simulated yields with the Hybrid Maize model and measured yields; calculated economic benefit and nutrient use efficiency; and estimated greenhouse gas emissions using published equations approximating nitrous oxide emissions as a function of N fertilizer rate. On average, the NE, FP, and OPTS treatments attained yields of 80%, 74%, and 77% of the potential yield, respectively. The exploitable yield gap between the NE and FP treatments was 0.9tha−1, and between the NE and OPTS treatments was 0.5tha−1. On average, the NE treatment increased the gross return above fertilizer cost (GRF) by US$303 and US$167 compared with the FP and OPTS treatments across all sites, respectively, in which about 91% and 98% of increase GRF was attributed increase in grain yield rather than reduction in fertilizer cost. There were slightly higher nutrient use efficiencies under the NE treatment than under the OPTS treatment. Relative to the FP treatment, however, on average, the NE treatment increased recovery efficiency of N, P, and K by percentage point of 12, 15, and 10, respectively. Agronomic efficiency of N, P, and K were increased by 6, 35, and 10kgkg−1, respectively. Finally, partial factor productivity increased by 14kgkg−1 for N and 45kgkg−1 for P while decreased by 29kgkg−1 for K. Furthermore, the calculated soil inorganic N at harvest of maize crop, total greenhouse gas (GHG, kg CO2 eqha−1) emissions, and GHG emission intensity (kg CO2 eqt−1 grain) were 42%, 17%, and 23% lower in the NE treatment than the FP treatment, respectively. We conclude that the Nutrient Expert for Hybrid Maize system has the potential to close existing yield gaps in the spring maize production systems of Northeast China by improving yield, nutrient use efficiency, and profitability with low environmental pollution.

Enhanced heavy oil recovery for carbonate reservoirs integrating cross-well seismic – A synthetic Wafra case study

Abstract Heavy oil recovery has been a major focus in the oil and gas industry to counter the rapid depletion of conventional reservoirs. Various techniques for enhancing the recovery of heavy oil were developed and pilot-tested, with steam drive techniques proven in most circumstances to be successful and economically viable. The Wafra field in Saudi Arabia is at the forefront of utilizing steam recovery for carbonate heavy oil reservoirs in the Middle East. With growing injection volumes, tracking the steam evolution within the reservoir and characterizing the formation, especially in terms of its porosity and permeability heterogeneity, are key objectives for sound economic decisions and enhanced production forecasts. We have developed an integrated reservoir history matching framework using ensemble based techniques incorporating seismic data for enhancing reservoir characterization and improving history matches. Examining the performance on a synthetic field study of the Wafra field, we could demonstrate the improved characterization of the reservoir formation, determining more accurately the position of the steam chambers and obtaining more reliable forecasts of the reservoir’s recovery potential. History matching results are fairly robust even for noise levels up to 30%. The results demonstrate the potential of the integration of full-waveform seismic data for steam drive reservoir characterization and increased recovery efficiency.

Nitrogen, Stover, and Tillage Management Affect Nitrogen Use Efficiency in Continuous Corn

Improving nitrogen use efficiency (NUE) in corn (Zea mays L.) is critical for optimizing yield and reducing environmental impact. Stover removal in continuous corn (CC) for biofuel production, coupled with reduced‐tillage systems, could alter NUE and residual soil nitrate‐N. Experiments were conducted in Minnesota over 3 yr to determine how N uptake, NUE, and residual soil nitrate‐N are affected by stover (remove and retain), tillage (chisel‐ [CT], strip‐ [ST], and no‐till [NT]), and fertilizer N (0, 45, 89, 134, 179, and 224 kg N ha−1) management. There was a linear response of grain and total aboveground N uptake to fertilizer N across stover management and tillage treatments. Stover removal increased recovery efficiency for ST and NT at fertilizer N rates ≤134 kg N ha−1, but did not enhance N recovery in plots fertilized at rates >134 kg N ha−1. Internal efficiency was 5% greater with stover removal with no fertilizer N, but did not change with fertilizer N application. Stover removal did not affect agronomic efficiency in CT but did enhance it in ST and NT at fertilizer N rates ≤134 kg N ha−1. Residual soil nitrate‐N to a depth of 1.2 m was 10 to 16 kg NO3–N ha−1 greater with stover removal at fertilizer N rates of 134 to 224 kg N ha−1. Greater residual soil nitrate‐N with stover removal indicates a need for judicious management of N when stover is removed in intensively‐managed Upper Midwestern CC systems.

A Distribution Regularity Study about Ternary Composite Expulsion of Residual Oil within the Third Grade of Reservoir Bed in the Northeast Massif of Lamadian, Heilongjiang, China

In the Northeast massif of La (Lamadian), it is going into the later exploit period with higher containing water in reservoir. In order to increase recovery efficiency, it is needed to discover a potential extract ability of residual oil. By studying the higher sub-layer II 1-18 in the northeast massif of Lamadian oil field this time, based on developing a carefully detailed reservoir description for that, in terms of resisting inter layer recognition in single well, depositional microfacies delineation, and reservoir features study, combined with dynamic data, control factors and distribution of residual oil in that region are analyzed and concluded. The result illustrated that the vertical rhythmic structure of reservoir is closely related to residual oil distribution, some different models of residual oil can be distinguished by rhythm; additionally, the planimetric position of residual oil is mainly controlled by depositional microfacies and reservoir features, planimetric heterogeneity, as well as inject-exploit relation.