LIANG Yukai, ZHENG Hua’an, ZENG Qianyi, SONG Jifeng, TIAN Zhongyuan, JIANG Shu
The Yinggehai Basin is a key area for natural gas exploration in the western South China Sea. In recent years, commercially viable gas formations and abundant high-temperature formation water have been discovered in the Huangliu Formation of the X gasfield, indicating promising prospects for hydrothermal geothermal resource development. However, geothermal resource evaluation for this system are still lacking. Taking the X gasfield in the Yinggehai Basin as a case study, a heterogeneous 3D geothermal reservoir geological model was constructed by integrating drilling, logging, core, and seismic data. Key properties such as porosity, permeability, temperature, and water saturation were modeled and assigned in a gridded format. During the model construction, multiple stochastic simulations and seismic attribute constraints were introduced to enhance the rationality and accuracy of the spatial distribution of geological parameters. Based on this model, the volumetric method was applied to evaluate the geothermal resource potential of the Huangliu Formation, and the main geothermal resource-rich zones were identified. The results showed that the reservoir temperatures in the Huangliu Formation ranged from 167.0 ℃ to 197.6 ℃, with an average of 186.5 ℃, indicating favorable conditions for high-temperature geothermal development. The total geothermal resource was estimated to be 3.84×10¹⁶ kJ, equivalent to 1 310.5×10⁶ t of standard coal, with fine sandstone serving as the main reservoir lithology. Assuming a recovery coefficient of 8%, the recoverable resource was approximately 0.31×1016 kJ, equivalent to standard coal of 104.8×10⁶ t. The spatial distribution of resources revealed two major geothermal-rich zones, both located in the sand bodies of deepwater turbidite channels of the Huangliu Formation. These zones were characterized by high temperatures, favorable physical properties, and well-developed fine sandstone, making them preferred areas for future development. Meanwhile, water saturation model analysis indicated high water content in both the eastern and western parts of the Huangliu Formation, suggesting the presence of isolated water bodies that could serve as potential development areas. The research results provide clearer insights into the distribution characteristics and development potential of geothermal resources in the Yinggehai Basin and offer important guidance for promoting the integrated development of offshore gas fields and geothermal energy in China.
Petroleum refining. Petroleum products, Gas industry
<b>[Objective]</b> China's backbone natural gas pipeline network comprises numerous large-diameter and long-distance pipelines.Periodic pigging operations play a crucial role in ensuring the safe, stable and efficient operation of these pipelines. However, since current pigging operations rely heavily on operator experience and the establishment of monitoring points, the inability to simulate pigging schemes in advance prevents accurate prediction of parameters such as the operating speed, position and arrival time of the pig, and pressure changes in the pipe. <b>[Methods]</b> To address this challenge, a mathematical model for dynamic prediction of the pigging process was constructed and put into practice according to the characteristics of actual pigging operations. Subsequently, the software for dynamic prediction of the pigging process was developed and applied to the actual pigging operations of several sections(A-B, B-C and D-E) of a designated pipeline for predicting the pigging time and pigging speed. <b>[Results]</b> The improved two-phase flow transient pigging model and the dynamic prediction software accurately forecast critical parameters, including the running speed, position and arrival time at each station of the pig during the pigging process; The accuracy of the dynamic pigging prediction technology and the reliability of the software were verified using the monitoring data of 52 actual pigging operations; And compared with actual measurements, the software's predictions had average relative errors of 5.94% for pigging time and 6.56% for pigging speed. <b>[Conclusion]</b> The utilization of the dynamic prediction technology and software enables efficient preparation of pigging operation schemes for natural gas pipelines, reduces manual workload, ensures pigging process safety, and enhances pipeline management intelligence.
Husnu Gerengi, Muhammed Maraşlı, Marziya Rizvi
et al.
This study evaluated the corrosion behavior of steel hooks embedded in GFRC, which were protected by a zinc-rich (96% Zn) galvanizing coating. The coating provided the hooks with active cathodic protection and a passive physical shield. Macrocell corrosion may form when the anode is smaller than the total steel surface. Thus, the steel hooks at the embedment juncture were additionally sealed against water ingress and air exchange using a construction sealant. The study was conducted in three phases in a salt-spray chamber. First, the electrogalvanized steel hooks embedded in GFRC were allowed to freely corrode for 7 days. In the second phase, the electrogalvanized steel hooks were painted with the zinc-rich coating and observed over 7 days. In the third phase, the steel hooks were protected by the zinc-rich coating together with a primer and construction sealant, and observed over 7 days. To evaluate the electrogalvanized hooks and the corrosion products formed, the thickness of the material was measured. Corrosion on the metal surface was inferred by studying the surface morphology of the hooks at various points of contact and after different periods of time.
Oils, fats, and waxes, Petroleum refining. Petroleum products
<b>[Objective]</b> Due to the scarcity of helium resources, insufficient production, high external dependence and single source, the security situation of helium resources in China is very severe. Utilizing salt caverns for helium storage is a significantly advantageous technology for large-scale helium storage that can effectively guarantee the helium supply capacity and improve helium security. However,China is devoid of underground salt cavern helium storage in operation, and related research and construction are still in the stage of initial development, requiring targeted feasibility and key technology researches. <b>[Methods]</b> Based on an investigation of helium resources and helium storage construction as well as China's experience in salt cavern gas storage construction, the feasibility of salt cavern helium storage construction in China was analyzed, and the suggestions on the development of key technologies for salt cavern helium storage were proposed,such as site evaluation, airtightness evaluation, cavern construction, storage construction, and helium injection and extraction. <b>[Results]</b> China is facing a high risk of helium supply disruption, necessitating the enlargement of reserve capacity. Salt cavern is suitable for large-scale helium storage for its satisfying performance in security and airtightness. The construction of salt cavern helium storage is feasible to increase China's helium reserve, giving that China has abundant salt cavern resources and a technological base for cavern construction. In addition, it is necessary to perform targeted research on key technologies for salt cavern helium storage construction, considering the geological conditions and helium resource conditions for storage construction in China differ from those in foreign countries. The salt mine in the southeast coastal area is close to the import and consumption of helium, and the transportation cost is low, so it can be used as the preferred storage site for the construction of salt cavern helium storage in China. <b>[Conclusion]</b> It is recommended to construct salt cavern helium storage in China in stages.At the early stage, 1 to 2 helium storage caverns should be constructed to explore and verify the construction technology of helium storage and ensure a stable supply of helium in China, after that more caverns should be constructed gradually to build up a strategic reserve that can meet China's helium demand for 5 to 10 years.
郑爱芳1,2,3,4， 何欢1, 高晔1, 张名雪1， 王煦1， 赵凯1,2 ZHENG Aifang1,2,3,4, HE Huan1, GAO Ye1, ZHANG Mingxue1， WANG Xu1，ZHAO Kai1,2
为预防花生储藏过程中的黄曲霉污染，从农田土中分离出2株拮抗芽孢杆菌，通过平板对峙法优选出1株作为研究对象，研究其对黄曲霉的抑制效果及对花生采后黄曲霉污染的防控效果。采用平板对峙法检测拮抗菌的抑菌广谱性并绘制生长曲线，并通过生理生化实验、形态特征观察及16S rDNA序列分析对该菌株进行鉴定。结果表明：优选出拮抗菌B419作为研究对象，其可有效抑制黄曲霉的生长，在拮抗菌浓度为1.0×106 CFU/mL，黄曲霉孢子浓度为1.0×103 CFU/mL时，黄曲霉孢子萌发抑制率达到98%；相比拮抗菌无菌发酵滤液和拮抗菌细胞悬浮液，拮抗菌发酵液防治花生黄曲霉污染效果最好；该菌株对互隔交链孢霉、枝孢霉、青霉、拟盘多毛孢等多种霉菌都有抑制作用，对大肠杆菌、酵母菌也有抑制作用；该菌株在培养4 h后进入对数期，14 h达到最大，26 h后进入衰亡期；该菌株被鉴定为贝莱斯芽孢杆菌（Bacillus velezensis）。综上，分离的拮抗菌B419对多种微生物都有抑制作用，不仅可以用来预防花生储藏过程中的真菌污染，在防治植物微生物病害方面也具有良好的应用潜力。In order to prevent Aspergillus flavus (A. flavus) contamination of peanut during storage, two antagonist Bacillus sp. were isolated from farmland soil, and one was screened as the subject to study its inhibitory effect on A. flavus and its preventive and control effect on A. flavus contamination of postharvest peanut by plate confrontation method. The inhibitory broad-spectrum of the antagonistic bacterium was detected by plate confrontation method and its growth curve was plotted. The strain was identified through physiological and biochemical test, colony morphological characteristics observation and 16S rDNA gene sequences analysis.The results showed that B419 was screened as the antagonistic bacteria on A. flavus; it could inhibit the growth of A. flavus, and the inhibition rate of A. flavus spore germination could reach 98% when the concentration of antagonistic bacteria was 1.0×106 CFU/mL and the concentration of A. flavus spores was 1.0×103 CFU/mL. Compared with antagonistic bacteria sterile fermentation filtrate and antagonistic bacteria cell suspension, antagonistic bacteria fermentation broth had the best prevention effect on peanut A. flavus. This strain had inhibitory effects on various molds such as Alternaria altemata, Cladosporium sp. , Penicillium sp. and Pestalotiopsis sp. , as well as on Escherichia coli and yeast. The strain entered the logarithmic phase after 4 h of incubation, reached a maximum at 14 h, and entered the decay phase after 26 h of incubation. The strain was identified as Bacillus velezensis. In summary, the isolated antagonistic bacteria B419 has inhibitory effects on various microorganisms, it can not only be used to prevent fungal contamination during peanut storage, but also has good potential in the control of plant microbial diseases.
Clavijo-Bernal Enrique J., Martínez-Force Enrique, Garcés Rafael
et al.
Climate change is forcing our societies to undertake socioeconomic changes to mitigate greenhouse gas emissions, primarily carbon dioxide, which continue to rise globally. Governments are applying policies to offset carbon emissions, despite the significant economic impact. Biotechnology offers solutions to dampen this impact, particularly in agriculture and industry, where plant biotechnology enhances production efficiency while reducing environmental impact. Camelina sativa, a climate-flexible oilseed crop with low agronomical exigence, offers promising alternatives to petroleum-derived oils. Oil derived from camelina seeds has the potential to substitute petroleum as the feedstock for the production of oleochemicals, which are compounds derived from vegetable or animal oils and/or petrochemical feedstock. The deep knowledge of the camelina genome, together with the optimized process to obtain genetically engineered camelina lines with on-demand modified oils, makes this oilseed crop a workhorse to counteract the environmental impact derived from human activity.
Based on the results of drilling, tests and simulation experiments, the shales of the Cretaceous Qingshankou Formation in the Gulong Sag of the Songliao Basin are discussed with respect to hydrocarbon generation evolution, shale oil occurrence, and pore/fracture evolution mechanism. In conjunction with a substantial amount of oil testing and production data, the Gulong shale oil enrichment layers are evaluated and the production behaviors and decline law are analyzed. The results are drawn in four aspects. First, the Gulong shales are in the stage of extensive hydrocarbon expulsion when Ro is 1.0%–1.2%, with the peak hydrocarbon expulsion efficiency of 49.5% approximately. In the low–medium maturity stage, shale oil migrates from kerogen to rocks and organic pores/fractures. In the medium–high maturity stage, shale oil transforms from adsorbed state to free state. Second, the clay mineral intergranular pores/fractures, dissolution pores, and organic pores make up the majority of the pore structure. During the transformation, clay minerals undergo significant intergranular pore/fracture development between the minerals such as illite and illite/smectite mixed layer. A network of pores/fractures is formed by organic matter cracking. Third, free hydrocarbon content, effective porosity, total porosity, and brittle mineral content are the core indicators for the evaluation of shale oil enrichment layers. Class-I layers are defined as free hydrocarbon content equal or greater than 6.0 mg/g, effective porosity equal or greater than 3.5%, total porosity equal or greater than 8.0%, and brittle mineral content equal or greater than 50%. It is believed that the favourable oil layers are Q2–Q3 and Q8–Q9. Fourth, the horizontal wells in the core area of the light oil zone exhibit a high cumulative production in the first year, and present a hyperbolic production decline pattern, with the decline index of 0.85–0.95, the first-year decline rate of 14.5%–26.5%, and the single-well estimated ultimate recovery (EUR) greater than 2.0×104 t. In practical exploration and production, more efforts will be devoted to the clarification of hydrocarbon generation and expulsion mechanisms, accurate testing of porosity and hydrocarbon content/phase of shale under formation conditions, precise delineation of the boundary of enrichment area, relationship between mechanical properties and stimulated reservoir volume, and enhanced oil recovery, in order to improve the EUR and achieve a large-scale, efficient development of shale oil.
Due to the unique landform in northern Shaanxi,the gas transmission pipeline through this area is found with considerable undulation.Liquid accumulation is likely to occur in low points and up-dip sections of pipelines,associated with frequent slug flow,which seriously impact the normal production of gas field.The prediction of critical liquid-carrying velocity is of great significance to reduce the harm brought by liquid accumulation and guide the design of the surface wet gas pipeline.Therefor,the critical liquid-carrying velocity prediction model for wet gas pipelines with undulation was built based on the minimum gradient method combined with uniform design and BP neural network,using the extended dual-fluid separated flow model.The model was validated using the field operation data of the Yan'an gas field.The wellhead temperature,pipeline operation pressure,water volumetric fraction,up- and down-slope angles,and pipe diameter were discussed with respect to their effects on the critical liquid-carrying velocity and their interactions,and then ranked through grey relational analysis(GRA).The results show that the critical liquid-carrying velocity is negatively correlated with the pipeline operation pressure and down-slope angle,and positively correlated with the wellhead temperature,water volumetric fraction,up-slope angle and pipe diameter.It is found that the proposed model is practical and operable for predicting the critical liquid-carrying velocity for the undulating surface pipelines of the Yan'an gas field and provides theoretical support for the prediction and prevention of liquid accumulation.
Chemical engineering, Petroleum refining. Petroleum products
Several international oil companies had conducted petroleum exploration, but failed to make any commercially viable discoveries in the Doseo Basin for over 30 years. In this article, an integrated analysis, based on the latest seismic and drilling data combined with exploration practice and tectonic, sedimentary as well as petroleum-geological characteristics of the basin, has been conducted with the aim to disclose the key factors of hydrocarbon accumulation and enrichment and then to find the potential petroleum plays. The Doseo Basin in Chad is a Meso-Cenozoic lacustrine rift basin developed on the Precambrian crystalline basement in the Central African Shear Zone. It is a half graben rift controlled by the strike-slip fault at the northern boundary, and can be divided into two sub-basins, an uplift and a slope. The basin experienced two rifting periods in the Cretaceous and was strongly inverted with the erosion thickness of 800–1000 m during the Eocene, and then entered the depression and extinction period. Structurally, a large number of normal faults and strike-slip faults are identified in the basin, and the boundary faults are inverted faults with normal at first. The main structural styles include inverted anticlines, fault noses, complex fault-blocks and flower structures. The Lower Cretaceous is the main sedimentary strata, which are divided into the Mangara Group, Kedeni, Doba and Koumra Formations from bottom to up. Two transgressive-regressive cycles developed in the Lower Cretaceous indicates with mainly lacustrine, fluvial, delta, braided-delta, fan-delta sandstone and mudstone. The effective source rock in the basin is the deep-lacustrine mudstone of the Lower Cretaceous containing the type I and type II1 organic matters. Furthermore, Inverted anticlines and fault-complicated blocks comprise the main trap types and the Kedeni Uplift is the most favorable play, followed by the Northern Steep Slope and Southern Gentle Slope. Lateral sealing capacity of faults controls the hydrocarbon abundance.
郭旭1,2，张东2，孙晓丽1，田荣荣1GUO Xu1,2, ZHANG Dong2, SUN Xiaoli1,TIAN Rongrong1
为改善紫苏籽油的品质，对紫苏籽在不同条件下焙炒（温度140~180 ℃，时间10~30 min）预处理后提取紫苏籽油，测定不同焙炒条件下紫苏籽油理化性质（色泽、酸值、过氧化值、共轭二烯含量、共轭三烯含量）和化学组成（脂肪酸、生育酚、甘油三酯），研究焙炒对紫苏籽油品质的影响。结果表明：焙炒温度在140~180 ℃，随焙炒时间的延长，紫苏籽油的色泽逐渐加深；酸值整体低于未焙炒的，过氧化值在140、160 ℃变化不明显，在180 ℃先升高再降低；共轭二烯和共轭三烯的含量在140、160 ℃变化不明显，在180 ℃增加明显；生育酚含量在180 ℃下损失明显，而脂肪酸和甘油三酯的组成和含量无明显变化。综合各指标，焙炒温度140~160 ℃和焙炒时间10~20 min条件下焙炒紫苏籽得到的紫苏籽油品质良好。
To improve the quality of perilla seed oil, perilla seed oil was extracted after pretreatment by roasting under different conditions (temperature 140-180 ℃, time 10-30 min), and the physicochemical properties (color, acid value, peroxide value, conjugated diene content, conjugated triene content) and chemical composition (fatty acids, tocopherols, triglycerides) of perilla seed oil were determined to study the effect of roasting on the quality of perilla seed oil. The results showed that with the increase of roasting time，the color of perilla seed oil deepened at 140-180 ℃, the acid value was lower than that of the oil prepared with the unroasted perilla seed, the peroxide value did not change significantly at 140 ℃ and 160 ℃, but increased and then decreased at 180 ℃, the content of conjugated diene and conjugated triene did not change significantly at 140 ℃ and 160 ℃, but increased significantly at 180 ℃, and the tocopherols content lost significantly at 180 ℃，while the composition and content of fatty acids and triglycerides did not change significantly. In summary,the quality of perilla seed oil obtained by roasting perilla seeds at 140-160 ℃ for 10-20 min was good.
Abstract Understanding the formation damage surrounding the well during the drilling operation is the key to predict damage degree and protect the formation in oil/gas reserviors. Based on the core drainage results, we obtained an empirical relationship between the invasion volume of drilling fluid and permeability reduction of formation. Furthermore, the equation is incorporated into a commercial reservior numerical simulation simulator to characterize the behaviors of drilling fluid invasion process. The results show that, although the invasion depth in low permeability reservoirs is short with the range of 1.7–2.5 m, the effect on recovery factor is significant due to the narrow seepage area in the near fracture region. When considering the formation damage, the pressure in the near-fracture damage region drops sharply, leading to a three-stage shape in pressure distribution curve. In addition, we found that high viscosity and low density oil-based slurry and shorter soaking period are conducive to decrease the formation damage during drilling operation. This work reveals the fundamental mechanisms of formation damage in low permeability reservoirs, which is a theoretical basis in formulation drilling fluids and optimization operation parameters.
Drilling through active shale formations has been a challenging practice in the oil and gas industry for a long period of time, given the complexity of shale structure and its interaction with Water Based Muds (WBMs). Although there have been many additives and methodologies proposed for a safe drilling through shale formations using WBMs, little success has been reported to the application of these methods once tested under different field conditions. In this paper, a new WBM formulated by nanomaterials was proposed to stabilize active shale layers during drilling. A series of rheological, density, filtration loss, bentonite dispersion and shale recovery tests were conducted on the mud samples formulated by nanosilica and Nano Glass Flakes (NGFs). The results indicated that NGF, as a cheap but effective nanomaterial, is able to significantly reduce the flirtation loss without posing any significant impacts on the density and the rheology of WBMs. It also appeared that the bentonite molecules were incapable to either hydrate or disperse in the drilling fluid system in the presence of NGFs. It seems that NGFs can stabilize clay minerals and reduce the filtration loss as remarkably efficient additive, but caution must be taken to ensure that they are properly disperse in the WBMs.
Petroleum refining. Petroleum products, Engineering geology. Rock mechanics. Soil mechanics. Underground construction
Through a case study to the gas pipeline network of Suzhou Industrial Park, a corrosion risk assessment model of gas pipeline network was established in combination with the risk assessment theory to assess the corrosion risk of the gas pipeline network in the industrial park. The assessment model adopted the fuzzy comprehensive evaluation method based on the improved AHP. By establishing the corrosion risk index system of gas pipeline network, the weight of each index was determined with the improved AHP method, the corrosion risk assessment level was established with the fuzzy comprehensive evaluation method, and finally the risk level of each pipeline section in the industrial park was solved. Excavation inspection was conducted for six gas pipelines in Suzhou Industrial Park randomly selected to judge the corrosion status of the pipeline, and the inspection results were compared with the evaluation results. The results show that the corrosion risk model can accurately assess the risk status of the gas pipeline network, and it is of some significance to improve the early warning and management level of the corrosion risk of city gas pipelines.