Soil Resources Research Articles

Response of maize yield to changes in soil organic matter in a Swedish long‐term experiment

AbstractAgricultural practices that lead to soil carbon sequestration may be a win–win strategy for mitigating global warming and improving soil fertility and resource use efficiency. The mechanisms through which soil organic carbon (SOC) concentration affects crop yields are numerous but difficult to separate. The objective of this study was to disentangle these processes and estimate to what extent the yield response to SOC is mainly driven by changes in physical or biochemical properties and processes. This was achieved by analysing the response of yields in continuous maize to SOC concentrations during 20 years (2000–2019), which had evolved in 14 experimental treatments in a Swedish long‐term field experiment at Ultuna since 1956, ranging from 0.94% to 3.65% in the topsoil (0–20 cm). Average maize yields during this period varied between 1.9 and 8.4 Mg dry mass per hectare in the different treatments. The treatments comprise applications of different mineral nitrogen (N) fertilizers and organic amendments and combinations thereof. Our analysis showed that maize yield in the treatments that were not severely limited by nitrogen supply or soil acidity increased by 16% for each percentage unit increase in SOC. We applied the widely used concept of critical N concentration in plant biomass to diagnose the N status in maize in the different treatments (N nutrition index [NNI]) and parameterized a response function between yield and pH (RpH). Dry soil bulk density (BD) was used as a proxy for soil physical properties. These three variables NNI, RpH and BD explained 95% of the variation in maize yields among treatments. Further analysis of the relationship between BD, SOC and plant available water capacity revealed that about two thirds of the yield increases in response to SOC change could be ascribed to associated changes in soil physical properties. Our analysis suggests that the extra storage capacity of water, which increased by up to 15 mm in the topsoil for each unit percentage increase in SOC, was the main driver for the observed yield responses. We conclude that measures for increasing SOC in soils most likely are an effective adaptation strategy for reducing the risk of crop damage during dry spells, which probably are becoming more frequent in the future due to climate change, even in relatively humid climates as in Sweden.

Short‐term conservation tillage degrades soil infiltration properties in the black soil region of Northeast China

AbstractSoil infiltration properties (SIPs) are crucial soil hydraulic parameters for hydrological and erosion models as they regulate the movement of water and nutrients within the soil. Tillage practice can significantly impact the hydrological and erosional processes of sloping farmland by changing SIPs through altering soil structure. Nevertheless, knowledge regarding the effects of short‐term conservation tillage on SIPs is unclear, which greatly limits the management of soil and water resources of sloping farmland. This study aimed to clarify the potential impact and underlying mechanisms of short‐term implementation of conservation tillage on SIPs under three typical tillage management types: conventional downslope tillage (DT), conservation contour tillage (CT), and no‐tillage (NT) in the black soil region of Northeast China. SIPs of initial infiltration rate (IIR), steady infiltration (SIR), and hydraulic conductivity (Ks) were determined by a field disc infiltration experiment under pressure heads (h) of −3, −1.5, and 0 cm. The results revealed that short‐term implementation of conservation tillage management degraded SIPs, with a significant difference observed between DT and NT. In comparison to DT, the mean SIPs of IIR, SIR, and Ks of CT decreased by 27.5%, 31.2%, and 28.6%, and the corresponding reduced values of NT were 54.1%, 65.0%, and 65.5%, respectively. SIPs were significantly correlated with soil texture, bulk density (BD), capillary porosity (CP), total porosity (TP), field capacity (FC), saturated water content (SSWC), and organic matter content (SOM). Among these influencing factors, the variations in SIPs among different tillage management and soil layers were primarily influenced by differences in clay and gravel contents, FC, and SSWC and SSWC played the most critical role. These results highlight the substantial impacts and clarify the mechanisms of short‐term conservation tillage on SIPs, which is helpful for understanding the potential effect of short‐term conservation tillage management on hydrology and erosional processes, thereby improving the sustainable utilization of arable land.

Effects of thiobacillus bacteria on physiology and vegetative growth of pomegranate

The climate change and consequent degradation of soil and water resources have led to difficult conditions for farmers; thus, they should make intelligent decisions to face these statuses. Managing soil nutrient and mineral uptake by plants and its feasibility under harsh environment must be considered. Therefore, the present research was conducted to investigate the response of pomegranate variety Shishe Kab to Thiobacillus bacteria (B) and sulfur (S) fertilization. Treatments included sulfur fertilization (three levels: 0, 500 and 1000 g−1 tree) and inoculation with Thiobacillus bacteria (two levels: inoculated and non-inoculated). Totally, sulfur fertilization and inoculation with bacteria improved physiological and biochemical aspects and fruit production of pomegranate. Supplying S decreased soil pH, which the lowest value (5.2) was recorded in 500 g S tree−1 when accompanied with bacteria. Soil electrolyte leakage (EL) increased, when sulfur incorporated or when bacteria added to the soil. The interactive effects of B × S was significant on fruit diameter and weight, chlorophyll (Chl), carotenoid and potassium content, which were improved, although non-inoculated plants also showed high values of potassium content. Anthocyanin and total carbohydrate improved when bacteria inoculation was done; however, total acidity (TA) and total soluble solids (TSS) showed a significant decrease. The EL variable significantly decreased and tissue water content increased in this experiment, when inoculation or sulfur fertilization was used. The results obtained from present study emphasized on the necessity of using sulfur and Thiobacillus bacteria in increasing growth and yield and also chilling tolerance of pomegranate trees.

Research on thermal insulation materials properties under HTHP conditions for deep oil and gas reservoir rock ITP-Coring

Deep oil and gas reservoirs are under high-temperature conditions, but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability, resulting in distorted resource assessments. The development of in situ temperature-preserved coring (ITP-Coring) technology for deep reservoir rock is urgent, and thermal insulation materials are key. Therefore, hollow glass microsphere/epoxy resin thermal insulation materials (HGM/EP materials) were proposed as thermal insulation materials. The materials properties under coupled high-temperature and high-pressure (HTHP) conditions were tested. The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased; additionally, increasing temperature accelerated the process. High temperatures directly caused the thermal conductivity of the materials to increase; additionally, the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity. High temperatures weakened the matrix, and high pressures destroyed the HGM, which resulted in a decrease in the tensile mechanical properties of the materials. The materials entered the high elastic state at 150 °C, and the mechanical properties were weakened more obviously, while the pressure led to a significant effect when the water absorption was above 10%. Meanwhile, the tensile strength/strain were 13.62 MPa/1.3% and 6.09 MPa/0.86% at 100 °C and 100 MPa, respectively, which meet the application requirements of the self-designed coring device. Finally, K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100 °C and 100 MPa. To further improve the materials properties, the interface layer and EP matrix should be optimized. The results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resource development.

Technology Focus: Geothermal Energy (March 2024)

As the world seeks transformative solutions to ensure a sustainable energy future, there is a growing interest in geothermal energy because of its versatility and evolving technologies that enable the application of low-enthalpy fluids. One area where the untapped potential of geothermal energy has been realized is in harnessing thermal energy from abandoned or inactive oil and gas wells. Such wells could be exploited for electricity generation or direct use through well repurposing. Three innovative papers elucidate the challenges, complexities, applicability, and key operational considerations associated with repurposing abandoned or idle oil and gas wells for geothermal energy. The first paper offers a comprehensive overview of 20 case studies from various countries, including actual and simulated cases. Downhole and surface parameters, including production scenarios, heat exchangers, circulation fluids, and power-generation efficiency, are meticulously examined. The investigation concludes with a positive outlook, highlighting the potential of producing geothermal energy from underused oil and gas wells. The second paper delves into the technical and economic feasibility of repurposing oil and gas wells specifically for community heating through geothermal energy. The multidisciplinary approach involves a thorough analysis of physical, technical, economic, and environmental aspects. The results showcase the potential benefits of repurposing low-temperature wells for community heating, emphasizing the cost-effectiveness and sustainability of this approach. The third paper introduces a geothermal assessment project conducted in an operational high-pressure/high-temperature field on the UK Continental Shelf. This innovative project uses a novel integrated work flow to assess the geothermal energy potential of offshore oil and gas assets and provides insights into CO2 emission reduction. The life of oil and gas wells can be extended through repurposing for geothermal energy production. The findings underscore the technical viability, economic feasibility, and environmental benefits of oil and gas well repurposing, providing a promising avenue for transforming existing oil and gas resources and infrastructure into contributors to a cleaner and greener energy future. Recommended additional reading at OnePetro: www.onepetro.org. SPE 213068 A Robust Screening Tool To Repurpose Hydrocarbon Wells to Geothermal Wells in Oklahoma by Esteban R. Ugarte, University of Oklahoma, et al. SPE 215554 A Feasibility Study of Geothermal Energy Extraction in the Baram Basin, Sarawak, Using Numerical Reservoir Simulation Based on Analog Data by M. Bataee, Curtin University Malaysia, et al. SPE 212075 Geothermal Energy in the Caspian Region: Study of Heat-Extraction Methods From Deep Wells by Dmitriy Abdrazakov, SLB

Development of Oil and Gas Condensate Fields

In the world, with the development of science, brand new technologies are being created to generate energy resources (e.g., hydrogen energy, electric car, etc.). These inventions will reduce the consumption and cost of hydrocarbon resources. This leaves oil and gas resource producers with only one option – accelerated development of oil and gas fields with low capital investment. This monograph is devoted to the development of oil and gas fields in a short period of time with a reduction in the volume of drilling operations and well quality by at least 50%. The developed technology of simultaneous split operation will give an impetus to volumetric production of hydrocarbons, accelerated field development and reduction of capital investments, as well as lead to the production of all recoverable and non-recoverable reserves from the subsoil. This monograph also delves into the technological aspects of operating wells in the Altyguyi gas condensate field. The scientific work examines the operational and technological aspects of hydrodynamic and thermohydrodynamic studies. To support this research, patents for invention No. 643 and 644, dated January 6, 2015, were obtained (application numbers 14/101317 and 15/101320). These patents cover the “Simultaneous method of separate and joint operation of several productive horizons by one chink and device for its realization” and the “Method of dual oil and gas production from one well in a multizone”. Based on the findings of the conducted analyses, studies, and calculations, the implementation of the intensification of the gas condensate field using the oil and gas DC method by one well is justified. This approach represents a first in global practice and aims to reduce capital investments and accelerate development.

Paleoenvironmental reconstruction and organic matter accumulation of the paleogene shahejie oil shale in the Zhanhua Sag, Bohai Bay Basin, Eastern China

The controlling factors of organic-rich shale accumulation is essential for the exploration and development of shale oil and gas resources. The sedimentary environment plays a vital role in the formation of organic-rich sediments in lacustrine facies. This article unravels the mineralogy, geochemistry, and paleoenvironmental evolution during the deposition of the Paleogene Shahejie Formation (Es3L). It discusses the effects of paleoclimate, paleosalinity, paleoredox conditions, paleowater depth, and paleoproductivity on organic matter (OM) enrichment. Finally, the OM enrichment model was established. The results show that the mineralogical compositions are mainly composed of calcite (avg. 40.13%), quartz (avg. 21.64%) and clay minerals (avg. 24.07%), accompanied by dolomite (avg. 7.07%), feldspar (avg. 6.36%) and pyrite (avg. 2.95%). The Es3L shale has a high abundance of OM, with total organic carbon (TOC) ranging from 1.07% to 5.12%. The organic matter type is mainly composed of type Ⅰ-Ⅱ1 kerogen, which is generally considered a good-quality source rock. The source of OM is a mixture of lower bacteria, algae, and plants. During the early sedimentary period, the paleoclimate was dry and cold, with high salinity, intense reducibility, and relatively low productivity. During the late sedimentary period, the climate became warmer and more humid. As a result, the salinity decreased to a level that was suitable for biological reproduction, and productivity increased gradually due to the input of terrigenous plants. Paleosalinity and paleoclimate determined the environment of the sedimentary period, in addition, paleoproductivity and paleoredox condition indicated the formation and preservation conditions of OM. The warm and humid climate, brackish water, suitable reduction conditions and high productivity are the favorable conditions for the generation and preservation of organic matter. The research results may have implications for the genetic mechanisms of organic matter accumulation. They will provide theoretical and technical insights into the exploration and development of shale oil.

ڕۆڵی هەرێمی كوردستان لە دابینكردنی وزەی وڵاتانی ئەوروپا: توێژینەوەیەک لە دەرفەت و ئاڵنگارییەکان

This research discusses the role of the Kurdistan region in supplying energy to European countries, with the most obvious challenges facing the region in this issue. the variables have been examined in the form of a political-analytical study. this study attempts to answer the following key question: is the Kurdistan region able to meet Europe's energy needs? and what obstacles and challenges does it face in this regard? the study also assumes that despite its rich Oil and Natural gas resources, the Kurdistan region faces many challenges in supplying energy to European countries. to answer this question and hypothesis, the study relied on “analytical methods” and “qualitative analysis”. the study finds that the energy of the region has become of interest to European countries, which is due to the efforts of europeans to find different and alternative sources to meet their energy needs. however, there are many internal and external obstacles in the way of the Kurdistan region in meeting the energy needs of European countries.

Biochar improves fertility in waste derived manufactured soils, but not resilience to climate change

We present a soil manufactured from waste materials, which could replace the use of peat and topsoil in plant production and reduce the pressure on natural soil resources. We tested the effect of the manufactured soil on ecosystem functions and microbial communities with and without plants present, and with and without biochar addition (Experiment 1). The resilience of the soil in response to drought and flooding, and also the effect of biochar was also tested (Experiment 2). Biochar increased soil C and N regardless of plant presence and negated the effect of the plant on soil peroxidase enzyme activity. The manufactured soil was largely resilient to drought, but not flooding, with negative impacts on microbial communities. Results indicate that biochar could improve soil properties, but not resilience to climatic perturbations. Results suggest that manufactured soils amended with biochar could offer a useful alternative to natural soil in many contexts.

Taxonomic attribution of the haplic gleysols of the Azerbaijan Republic in world reference base for soil resources

<p><span>The aim of the research was to obtain new information about the genesis, status, diagnostic features, and properties of the meadow-boggy soils of the Azerbaijan Republic and to perform the taxonomic attribution of those soils in accordance with the international soil classification system in compliance with the world reference base (WRB) for soil resources. Field experiments, physical, and chemical analyses of soil samples were carried out by standard methods. The morphological properties of the meadow-boggy soils in the Greater Caucasus and Lankaran regions of Azerbaijan have been characterized. Carbonate sediments are almost always invisible in the upper layers (13.27-17.14% (No 426); 10.46-27.39% (No 5); 0.87-1.33% (No 55)). According to the humus content, they are not highly humic (1.44-1.85% (No 426); 0.90-1.58% (No 5); 3.10-3.29% (No 55) in the upper layers). The magnitude of the reaction of the soil solution varies from 8.0 to 8.5. For the first time, an attempt is made to determine the name of meadow-boggy soils in accordance with the international soil classification in compliance with the WRB 2015. The above soils are assigned to the gleysols reference soil group (RSG) with various principal and supplementary qualifiers.</span></p>

Walnut growers want rootstocks that can resist diseases

Abstract: English walnuts are the walnut species of choice for nut production. In the United States, edible English walnuts are almost exclusively produced in California, using soil and water resources on more than 370,000 acres. Scion cultivars of English walnuts are grafted onto rootstocks. Traditional rootstocks are seedling populations of so-called Paradox hybrids generated from crosses of black walnut with English walnut. These rootstocks are susceptible to soil-borne diseases, including crown gall, Phytophthora root and crown rot, and plant-parasitic nematodes. Strategies to respond to these diseases include the use of newly developed clonal walnut rootstocks with genetic resistance. In a survey conducted during 2020 through 2021, walnut growers revealed their willingness to pay higher prices for clonal walnut rootstocks with some disease resistance. The survey showed that they were most concerned with crown gall and nematodes, and were willing to pay significant price premiums for rootstocks that are resistant to these pathogens.

Effects of the Roasting-Assisted Aqueous Ethanol Extraction of Peanut Oil on the Structure and Functional Properties of Dreg Proteins.

The effects of the roasting-assisted aqueous ethanol extraction of peanut oil on the structure and functional properties of dreg proteins were investigated to interpret the high free oil yield and provide a basis for the full utilization of peanut protein resources. The roasting-assisted aqueous ethanol extraction of peanut oil obtained a free oil yield of 97.74% and a protein retention rate of 75.80% in the dreg. The water-holding capacity of dreg proteins increased significantly, and the oil-holding capacity and surface hydrophobicity decreased significantly, reducing the binding ability with oil and thus facilitating the release of oil. Although the relative crystallinity and denaturation enthalpy of the dreg proteins decreased slightly, the denaturation temperatures remained unchanged. Infrared and Raman spectra identified decreases in the C-H stretching vibration, Fermi resonance and α-helix, and increases in random coil, β-sheet and β-turn, showing a slight decrease in the overall ordering of proteins. After the roasting treatment, 62.57-135.33% of the protein functional properties were still preserved. Therefore, the roasting-assisted aqueous ethanol extraction of peanut oil is beneficial for fully utilizing the oil and protein resources in peanuts.

Effect of stand age on soil microbial metabolic limitation and enzyme activities in Robinia pseudoacacia L. plantations in the loess hilly‐gully region, China

AbstractSoil heterotrophic microorganisms play crucial roles in soil biogeochemical cycles by secreting extracellular enzymes, but their metabolism is often limited by resource availability. Identifying major resources that limit soil microbial metabolism could help to create reasonable management practices for the maintenance of ecosystem function. Robinia pseudoacacia plantations perform crucial functions in reconstituting the ecological integrity of disturbed ecosystems; however, soil microbial metabolic limitations in R. pseudoacacia plantations remain poorly understood. Herein, R. pseudoacacia plantations of four age classes (10, 22, 37, and 47 years old) were sampled in the loess hilly‐gully region of northern Shaanxi Province in China. This study analyzed the effects of stand age on soil extracellular enzyme activities and soil microbial metabolic limitation. It also determined the main factor driving soil microbial metabolic limitation and extracellular enzyme activities. The results of ecoenzymatic stoichiometry showed that nitrogen (N) limited soil microbial metabolism in R. pseudoacacia plantations. Soil microbial metabolism at 10 and 22 years old were more carbon (C)‐ and N‐limited than that at 37 and 47 years old. Except for N‐ and phosphorus (P)‐acquiring enzyme activities at 10–20 cm, soil C‐, N‐, and P‐acquiring enzyme activities (in 0–10 and 10–20 cm of soil) at 10 and 22 years old were significantly higher than those at 37 and 47 years old. The enzymatic ratio of C:N:phosphorus(P) acquisition in all R. pseudoacacia plantations, regardless of stand age and soil depth, deviated from 1:1:1. Soil nutrients explained most of the variation (90.80%) in soil extracellular enzyme activities based on variation‐partitioning analysis. The partial least squares path model showed that soil nutrients had the highest total negative effect on microbial C limitation and microbial N/P limitation. Our results confirmed that microbial metabolic limitation was induced by soil resource deficits. The findings provide another visual that increases our understanding of soil microbial metabolic limitation in R. pseudoacacia plantations.

Potential Development of Unconventional Oil and Gas Resources in Indonesia

The demand for energy is increasing along with the rise in population. Indonesian people rely on conventional resources such as coal, oil, and natural gas to meet their energy needs. It is estimated that coal can only be exploited for up to 61 years, natural gas for 34 years, and oil for 19 years. Meanwhile, Indonesia possesses unconventional oil and gas resources (e.g., coal bed methane (CBM), tight gas, shale gas and oil, and methane hydrate), estimated to reach 1,800 trillion cubic feet (TCF). These resources are in the exploration stage and have yet to be fully exploited due to technological limitations. Nevertheless, the Indonesian government continues to emphasize the development of this type of energy resource. Therefore, this study conducts a review of the potential of unconventional oil and gas resources in Indonesia, covering characteristics, potential occurrences in Indonesia, exploitation methods, utilization as a source of energy, and opportunities and challenges in their application. The method used is a narrative review based on secondary data by examining papers published in reputable national and international journals in the last ten years. Results show that unconventional oil and gas resources have different characteristics, including permeability, porosity, and depth. CBM can be found at the shallowest depth, followed by tight gas, methane hydrate, and the deepest is shale gas. Potential occurrences of these resources in Indonesia include gas hydrate (858.2 TCF), then shale gas (574.07 TCF), coal-bed methane (453.3 TCF), and shale oil 11.24 million tons. Exploitation can be done in various ways, such as dewatering for CBM, hydraulic fracking for tight and shale, and depressurization for methane hydrate. Once exploited, methane gas can be used for power plants, vehicle fuel, and industrial and household needs. Opportunities and challenges from various aspects, as well as applicable laws in Indonesia, are also discussed. In this light, the contribution of our study is to provide a comprehensive review of the characteristics, location, exploitation methods, opportunities, and challenges of utilizing unconventional oil and gas resources in Indonesia.

DISCUSSION ON ECOLOGICAL AQUACULTURE AND INNOVATIVE OPERATION STRATEGY

This study aims to improve the problems faced by Taiwan's aquaculture industry, such as the increased risk of drug residues caused by excessive use of water and soil resources and high-density farming, and to improve its competitiveness. Improve regional production and marketing operations, increase environmental protection production methods, and increase young people's willingness to return to their hometowns to invest. In order to increase consumers' trust in aquaculture aquatic products, basic safety requirements can be achieved through production and sales history labels, vacuum-sealed packaging, and clear labels, thereby enhancing consumer loyalty. Brand features and product discounts can also enhance loyalty. This study uses the focus group interview method to understand the problems of regional farming and the expected future prospects. Results found that it is possible to integrate regional farmers, establish sales channels for agricultural and fishery products in Chiayi, achieve sustainable development and improve competitiveness, and increase the willingness of young people to return to their hometowns to invest. To sum up, there are the following three propositions: (1) Construct cooperation channels to increase the added value of production and sales. (2) Introduce friendly breeding and increase product differentiation. (3) Establish an intelligent platform to train young people to return hometown. In addition, it is also suggested to combine the promotion of local recreational fishery and the characteristics of e-commerce distribution and sales to establish an operation model of online distribution and sales; and widely publicize Taiwan's seafood and aquatic product certification and inspection system to promote friendly farming methods to improve the existing breeding environment. Protect the sustainable environment and increase production value.

Karık ve Damla Sulama Yöntemleriyle Kırmızı Biberde Farklı Sulama Stratejilerinin Yaprak Osmotik Potansiyeli ile K ve Ca İyon Konsantrasyonları Üzerine Etkilerinin Belirlenmesi

A study was managed to identify the water stress effect on marketable yield, osmatic potential, and potassium (K) and calcium (Ca) ions for drip and furrow irrigated processing red pepper in the 2010 and 2011 growing seasons in Tarsus, Turkey. The treatments for drip irrigation; comprise full irrigation (DFI1.0), deficit irrigation DDI0.75, DPRD0.5, DFPRD0.5, and DDI0.5; for furrow irrigation; full irrigation (FFI1.0), fix alternative furrow (FAF0.5) and PRD furrow (FPRD0.5). FAF0.5 and FPRD0.5 received 50 % of the water applied to FFI1.0. In FAF0.5 the same furrows were irrigated while in FPRD0.5 irrigated alternately. Irrigation methods and irrigation levels had a remarkable effect on the total yield of red pepper in both experimental years. Drip irrigation treatments manufactured higher red pepper yields than the furrow irrigation treatments. The maximum yield in the drip irrigation system was acquired from the DFI1.0 treatment followed by DDI0.75, DDI0.5, and DFPRD0.5 treatments. Though DPRD0.5, DFPRD0.5, and DDI0.5 applied the same amount of water, DPRD0.5 resulted in a higher yield. In furrow treatments, FFI1.0 resulted in the highest yield followed by FPRD0.5 and FAF0.5. Water use efficiency (WUE) diminished with increasing the water amount for drip and furrow irrigation methods. While lower osmotic potential values were measured in full irrigation treatments in furrow and drip irrigation plots, higher osmotic potential values were determined in treatments where water stress was determined in both years. In both drip and furrow irrigation, the lowest Ca (%) values were obtained in full irrigation, while the highest Ca values were obtained in limited irrigation with water stress in the 2010 and 2011 years. K ion values were generally similar in the first and fourth pepper harvests in drip and furrow irrigation.

Effects of carboxylated styrene‐butadiene latex nanoparticles on channeling leakage and pore structure of oil well cement

AbstractThe exploitation efficiency of oil and gas resources depends on the cementing quality. In cementing engineering, interlayer migration occurs in the underground gas layer with cement hole as the main channel, which seriously threatens the sealing integrity of cement casing and leads to the failure of cementing operation. To improve the gas migration control ability of oil well cement (OWC), two carboxylated styrene‐butadiene latex nanomaterials styrene butadiene latex containing itaconic acid and sodium p‐styrene sulfonate (SBSI) and styrene‐butadiene latex containing methacrylic acid and sodium p‐styrene sulfonate (SBSM) were synthesized. The effects of SBSI and SBSM with different carboxyl structures on the gas migration control ability and pore structure of cement were investigated. The results show that the latex is densely packed on the cement matrix through the dissociation and adsorption behavior of carboxyl groups, and the smaller particle size and lower adsorption are more conducive to the formation of the film. The introduction of latex effectively shortened the transition time of cement gel state and significantly reduced the permeability of interlayer material migration. Compared with OWC, the transition time of cement containing SBSI and SBSM latex (SBSI/OWC and SBSM/OWC) decreased from 28 to 18 and 17 min, respectively, and the filter loss decreased from 60 to 40 and 36 mL, respectively. The isolation effect of the latex film on the interlayer gas and the provision of mechanical support have greatly improved the gas migration control ability of the cement and ensured the cementing quality. In addition, the refinement of cement pore structure caused by latex brings better rheological and mechanical properties to cement. This study clarified the change of latex in the gel transition stage of OWC from liquid to solid and revealed the mechanism of latex on the internal structure change of cement. It broadens the application range of latex nanomaterials in the field of OWC and provides a new possibility for the use of OWC in high temperature and high salt environment.

Research Status and Prospect of Liquid Carbon Dioxide Fracturing Technology

Liquid carbon dioxide fracturing technology has emerged as a novel unconventional method of retrieving oil and gas resources. As carbon dioxide is used as the fracturing fluid, it reduces the dependence on water resources and environmental pollution. The low viscosity and high diffusion properties of liquid carbon dioxide allow it to penetrate rocks more effectively, improving the efficiency of oil and gas extraction. In addition, the technology has potential carbon dioxide sequestration benefits that could help mitigate climate change. However, liquid carbon dioxide fracturing technology still faces challenges in terms of cost, technology maturity, and environmental impact. At present, academia and industry are actively engaged in research to improve the feasibility and economics of this technology, with the goal of providing new solutions for the sustainable development of energy in the future. This paper focuses on the research status and prospect of liquid carbon dioxide fracturing technology.

Toward a coordinated understanding of hydro-biogeochemical root functions in tropical forests for application in vegetation models.

Tropical forest root characteristics and resource acquisition strategies are underrepresented in vegetation and global models, hampering the prediction of forest-climate feedbacks for these carbon-rich ecosystems. Lowland tropical forests often have globally unique combinations of high taxonomic and functional biodiversity, rainfall seasonality, and strongly weathered infertile soils, giving rise to distinct patterns in root traits and functions compared with higher latitude ecosystems. We provide a roadmap for integrating recent advances in our understanding of tropical forest belowground function into vegetation models, focusing on water and nutrient acquisition. We offer comparisons of recent advances in empirical and model understanding of root characteristics that represent important functional processes in tropical forests. We focus on: (1) fine-root strategies for soil resource exploration, (2) coupling and trade-offs in fine-root water vs nutrient acquisition, and (3) aboveground-belowground linkages in plant resource acquisition and use. We suggest avenues for representing these extremely diverse plant communities in computationally manageable and ecologically meaningful groups in models for linked aboveground-belowground hydro-nutrient functions. Tropical forests are undergoing warming, shifting rainfall regimes, and exacerbation of soil nutrient scarcity caused by elevated atmospheric CO2. The accurate model representation of tropical forest functions is crucial for understanding the interactions of this biome with the climate.

EOR of heavy oil polymer on Alaska's North Slope: History matching challenges and solutions in a significant long-term water cut reduction

In 2016, a pilot program in Alaska's Milne Point Field tested polymer flooding for heavy oil recovery. Using four wells in the Schrader Bluff reservoir, it aimed to assess its effectiveness in capturing heavy oil resources. Generally, polymer flooding can boost oil production by 10-15%, typically occurring 6-9 months after injection. However, in this case, it took over 24 months for a polymer breakthrough. The method proved highly effective, consistently reducing water content by over 40% and maintaining a low level below 20% for 18 months. Applying standard simulation methods, like history matching, became challenging due to this prolonged low water cut. The usual history-matching processes focus on relative permeability, permeability corrections, and skin effect modifications. Nevertheless, these alternatives proved ineffective. In response to the extended low water cut in Alaska's North Slope, a unique approach was suggested. This approach entails highlighting the low-end point (Krw) across multiple relative permeability curves and adjusting these values according to the water cut history. Additionally, the method takes into account permeability adjustments, Equation of State on analyzes of oil viscosity, J-function incorporation, and considers the potential for viscous fingering during the process. The pilot program displayed remarkable polymer flooding effectiveness, but its unique performance on the North Slope required a modified history-matching approach to simulate its success accurately.