Hasil untuk "Oils, fats, and waxes"

Wang Xiaoming, Song Chenglin, Sun Wei et al.

Quantitative assessment was carried out on the sticking risk in the drilling and completion stage to fill the gap in this field， and provide scientific basis and technical support for the risk control of sticking in drilling operations. Based on the analysis of causes， inducing factors and common types of sticking， a fault tree model was constructed and mapped to a Bayesian network model. Using expert knowledge and real data from an oil field in Southwest Sichuan Basin， fuzzy analytic hierarchy process （FAHP） was used to quantify the risk of sticking， and the main risk factors affecting sticking were identified by sensitivity analysis. The research results show that human error is the main cause of sticking， with its contribution rate significantly exceeding other factors. Sensitivity analysis identifies key causal factors such as improper drilling parameters， inadequate connections and long rig downtime. The constructed model can dynamically update the risk probability， thereby effectively supporting risk warning and decision-making. The research conclusions not only provide theoretical support for the oil and gas industry， but also provide practical guidance for risk management in drilling operations， and have important engineering application value.

JIANG Beibei, LIU Jiabo, ZHANG Guoqiang, WANG Dong, LI Ying, LUO Hongwen, ZHOU Lang

In the context of the global carbon neutrality strategy, greenhouse gas emissions —mainly CO₂— are continuously rising, exerting adverse effects on the global climate, ecosystems, and human life. Geological storage of CO2 is an important technological approach to achieving carbon neutrality targets. As sealing barriers within potential storage formations, the sealing property of caprocks is crucial for the long-term or even permanent CO2 storage. Salt-gypsum caprocks exhibit favorable properties such as low porosity, low permeability, high structural stability, and high breakthrough pressure, making them promising candidates for long-term and secure CO2 storage. However, their physicochemical characteristics differ significantly from those of other lithological caprocks, posing challenges to evaluating their sealing performance for CO2 storage. Therefore, there is an urgent need to establish an evaluation method tailored to salt-gypsum caprocks. Firstly, based on the Analytic Hierarchy Process (AHP), a comprehensive evaluation index system was developed by considering key influencing factors, such as macro indicators, micro indicators, and breakthrough pressure, affecting the sealing performance of caprocks. Four grading levels were defined for each index, and the influence weight of each index on the sealing performance of salt-gypsum caprocks was determined. Secondly, by integrating the Fuzzy Comprehensive Evaluation Method, the total weight for evaluating the sealing performance of salt-gypsum caprocks for CO2 storage was calculated. This resulted in the development of a comprehensive evaluation method of CO2 storage sealing tailored to these types of caprocks. Finally, the method was applied to the Gaoshiti-Moxi block in the Sichuan Basin as a case study, where the CO2 storage sealing performance of its potential salt-gypsum caprock in a depleted gas reservoir was systematically evaluated. The results revealed that the total weight of the sealing performance evaluation of Gaoshiti-Moxi structural gas reservoir caprocks ranged from [2.5,3.0), corresponding to a grade of “relatively good”, indicating a relatively strong capacity for CO2 storage. This suggested the site was suitable for the future application of Carbon Capture and Storage (CCS) technology. The research results can provide technical guidance for site selection and storage safety evaluation of CO2 storage in depleted gas reservoirs with salt-gypsum caprocks.

Mi Kaifu, Shen Pengyu, Qiao Shihang et al.

The current staged deep shale gas testing and production mode cannot meet the requirement for interactions between surface processes and production data under complex conditions. Thus， it is necessary to develop a technology for integrated deep shale gas testing and production （hereinafter referred to as “integrated technology”） and associated equipment. Considering the complexities of deep shale gas such as high temperature and high pressure， multi-phase flowback and temperature and pressure fluctuation， an integrated technology featuring digital wellhead fine control and multi-phase separation intelligent metering was proposed. Through constructing a gas well choke production control and multi-phase two-dimensional separation control model， taking modular equipment as the carrier， the integrated technology was systematically analyzed. The field applications in deep shale gas fields of southern Sichuan Basin show that the number of process modules of the integrated technology is reduced by 60.6%， and the field operation time is shortened by 68.1%. For production capacity analysis， the dynamic control method of “fixed choke coarse adjustment + electric throttling fine adjustment” considering wellbore critical sand production can stably control the pressure drop rate of shale gas wells less than 0.1 MPa/d. For dynamic sand fluid discharge， the liquid level-time two-dimensional collaborative separation control method can effectively reduce the adjustment frequency of control units. The research results effectively improve the overall production efficiency of deep shale gas wells， and provide reference for the efficient development and optimal management of deep shale gas fields.

QU Jinghui, LIU Xingbin, LIU Dongmei et al.

The capacitance method is widely used to measure the water content of oil-water two-phase flow, whether it is the surface oil-water measurement or the stratification test of the production profile in the well. To measure the water holdup (water phase volume fraction), it is necessary to establish the relationship between the water holdup and the sensor capacitance, so it is necessary to establish the theoretical or empirical model of the miscible equivalent dielectric constant and the water holdup. Since the formation water produced from wells and tap water used in surface laboratory calibration have good electrical conductivity at low and medium frequencies, considering only the dielectric property without considering the electrical conductivity will have a significant impact on the accuracy of water retention measurement. Based on the effective electric field theory of dielectric polarization, the equivalent dielectric constant model of oil-water two-phase flow is established, considering water as a good conductor under the condition of low water content and fine bubble flow. According to this model, the equivalent permittivity of oil-water two-phase flow is determined only by the water holdup and the permittivity of oil phase, and has nothing to do with the permittivity of water phase and the conductivity of water phase. The correctness of the model is verified by preliminary experiments. The research is of great significance for the design and field application of the water content sensor for oil-water two-phase flow when the oil is continuous phase.

张沁强，陈竞男，姚双燕，窦伟国，彭丹，毕艳兰 ZHANG Qinqiang, CHEN Jingnan, YAO Shuangyan, DOU Weiguo, PENG Dan, BI Yanlan

为减少甾醇酯的生产工序，提高大豆油脱臭馏分重相组分中总甾醇得率，采用柱层析法直接分离提取甾醇酯，通过单因素试验考察吸附剂种类、上样量、洗脱剂比例和柱长直比（填料高度与直径比）对甾醇酯产品纯度和得率的影响，确定最佳工艺条件，并对最佳工艺条件下分离提取的甾醇酯产品进行傅里叶红外光谱表征，以及甾醇组成和脂肪酸组成测定。结果表明，柱层析法分离提取甾醇酯的最佳工艺条件为吸附剂为硅胶（粒径50~75 μm），上样量0.5 g，洗脱剂比例为正己烷、乙醚、冰乙酸体积比95∶ 5∶ 1，柱长直比16∶ 1。在最佳工艺条件下，甾醇酯产品纯度为(89.90±0.94)%，得率为(9615±1.49)%；傅里叶红外光谱分析证实提取的产品中含甾醇酯，甾醇酯上的甾醇组成主要为β-谷甾醇、豆甾醇、菜油甾醇，脂肪酸组成主要为亚油酸、油酸、棕榈酸、硬脂酸和亚麻酸。综上，柱层析法无需复杂工序，即可实现大豆油脱臭馏分重相组分中甾醇酯的有效回收。In order to reduce the process of sterol ester production and increase the yield of total sterols in the waste residue of soybean oil deodorizer distillate (WRSODD), column chromatography was used to extract the sterol esters from WRSODD. The influence of absorbent type, sample loading amount, eluent ratio and ratio of column material height to diameter on the recovery rate and purity of sterol esters were examined by single factor experiment, and the optimum process conditions were selected. The sterol esters obtained under the optimum process conditions was analyzed by Fourier-infrared spectroscopy, and its sterols and fatty acid compositions were analyzed. The results showed that the optimum conditions were as follows: with silica gel powder (particle size 50-75 μm) as absorbent, sample loading amount 0.5 g, volume ratio of a mixture of n-hexane, diethyl ether and glacial acetic acid 95∶ 5∶ 1, and ratio of column material height to diameter 16∶ 1. Under these conditions, the purity and recovery rate of sterol esters were (89.90±0.94)% and (96.15±1.49)%, respectively. Fourier-infrared spectroscopy results verified that the product contained sterol esters. The sterol compositions of sterol esters were mainly β-sitosterol, stigmasterol and campesterol. The fatty acid compositions were palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. In conclusion, effective recovery of sterol esters from the waste residue of soybean oil deodorizer distillate can be achieved through column chromatography without complex process.

Sun Jiaxiang, Zhao Hongshan, Ma Li

The strata below the Qingshuihe Formation in the Junggar Basin are found with high uncertainty,low drillability and complicated pressure system,which severely restrains the progress of exploration and development by deep exploration wells in the lower-assemblage reservoirs.Therefore,the challenges in drilling deep layers in Well Zheng 10 were analyzed,and the key technologies were discussed,including optimization of casing program,development of special-shaped-cutter PDC bit,high-efficiency wellbore-stabilizing drilling fluid system and constant-bottomhole-pressure drilling.The results show that,the package of technologies for deep exploration wells in the lower-assemblage reservoir enabled Well Zheng 10 to record the largest well depth(7 802 m)in the Junggar Basin.The combination of the ridged-cutter PDC bit and the durable positive displacement motor(PDM)with uniform wall thickness has allowed an enhanced rate of penetration(ROP)in deep layers of the Junggar Basin hinterland.The synthetic-based drilling fluid can effectively suppress wellbore chipping due to hydration swelling of water-sensitive strata induced by drilling fluid filtrate invasion,and it is preferred for avoiding wellbore instability and ensuring wellbore quality in target layers in central Junggar Basin.The research findings provide guidance for the enhancement of ROP and efficiency in complex ultra-deep well drilling.

Sun Qiaolei, Jin Zuwen, Wang Jiangang et al.

In order to analyze the operation strength of HXJ180 offshore workover rig under various complex working conditions,the command stream method was used to build a workover rig model.By means of numerical simulation on the operation strength of the workover rig in 32 sub-working conditions corresponding to 4 working conditions and 8 wind directions,the cloud chart of displacement and equivalent stress distribution of the workover rig was obtained.Based on the <i>UC</i> value determination method in AISC 360—16,the operation strength of workover rig under various working conditions was checked and verified.The study results show that under all working conditions,the maximum equivalent stress is concentrated at the front end of the pipe setback region of upper movable base,and the wind direction has little effect on the position of the maximum stress point.Under two working conditions,the wind direction has little effect on the displacement distribution of the workover rig,and the maximum displacement point is located in the region of derrick crown base and bearing beam of gas-solid pipeline respectively.Under the unexpected and expectable working conditions,the wind direction has a significant impact on the displacement distribution of the upper part and monkey board of the derrick,and the maximum displacement point is also mainly concentrated in the region.Under all working conditions,the maximum <i>UC</i> value of the component occurs at the front end of the pipe setback region of upper movable base,and the maximum <i>UC</i> value is less than 1,indicating that the comprehensive strength of the workover rig is enough to meet the operating requirements of the API standard.The analysis method and related results in this paper provide reference for strength check and design improvement of drilling and workover rigs.

Mukhutdinov N.U., Khozhiev B.I., Karshiev O.A. et al.

The article discusses the features of the geological structure, the identification of petroleum bearing promising zones and the scientific substantiation of the optimal areas of prospecting and exploration for the Khorezm monocline and adjacent territories through a comprehensive analysis of cosmo-geological study and geological and geophysical data. A comprehensive interpretation made it possible to minimize the existing multivariance in solving certain problems related to the tectonic features of the study area, determining possible zones of oil and gas accumulation, identifying fracture zones, predicting structural traps of the sedimentary cover for setting prospecting seismic surveys in a poorly studied, but potentially petroleum bearing promising territory of Uzbekistan.

Hongju Chen, Shunkang Fu, Shuai Chai et al.

With the exploration and development of oil and gas fileds going towards into deep-water fields, high waxy reservoir has much more flow assurance issues of encourage complex solids depositions in the transportation system, especially hydrates and wax. Applying risk management such as hydrate slurry technology to control hydrate blockage, has much more economic and technical advantages, comparing to the traditional methods. It is significant to understand the viscosity of the waxy-hydrate slurry using hydrate slurry technology in high wax content reservoir. In this work, based on a simplification idea by coupling the wax content effect into the viscosity, volume and density of the water-in-waxy oil emulsion, a new viscosity model of waxy-hydrate slurry is established according to the Einstein effective medium theory, based on the experiments carried out in a high-pressure rheology system with different wax contents ranging from 0.5 wt%∼2.0 wt%. The effect of the complex aggregate coupling wax-hydrate-water is considered by function the non-Newtonian coefficient by four dimensionless parameters. Well-fitting results within an improved deviation of ±15% indicate the feasibility of this method is feasibility. This work can provide a valuable reference for the application of hydrate slurry technology in deep-water fields with high wax content reservoir.

Wang Changxu

In order to quantitatively evaluate the water flooding effect and remaining oil distribution in thin and poor reservoirs in Daqing Changyuan Oilfield, and to explore the method to maximize the remaining potential of thin and poor reservoirs, the technical difficulties of continuous closed coring in horizontal wells in thin reservoirs were analyzed. Based on this, closed coring tools with different specifications were developed for horizontal wells in thin reservoirs. Combining with the BHA, three types of drilling assembly were developed, namely inclination-increase type, inclination-stabilization type and inclination-decrease type. By means of LWD monitoring while drilling, continuous coring from horizontal wells in thin reservoirs was completed and meanwhile the wellbore trajectory was adjusted. The application results of Well Xing 6-20-Jianping 647 in Daqing Oilfield show that, this coring tool performs well in precise control of wellbore trajectory and closed coring simultaneously. For the first time, 315.54 m of continuous coring was completed in the target with only 0.6～1.0 m effective thickness, with coring harvest rate of 99.76% and closed rate of 97.10%. It created the longest record of continuous closed coring from thin reservoir horizontal wells for the first time in China and achieved good application results. The research results could provide some references for the effective development of three types of reservoirs in Daqing Changyuan Oilfield.

Alireza Noohnejad, Kaveh Ahangari, Kamran Goshtasbi

Abstract Use of vital geomechanical parameters for determination of safe mud pressure window is generally associated with high level of uncertainty primarily because of absence of sufficient calibration data including laboratory and field test information. The traditional deterministic wellbore stability analysis methodologies usually overlooked the uncertainty of these key parameters. This paper exhibits implementing a quantitative risk assessment technique on the basis of Monte-Carlo modeling to consider uncertainty from input data so as to make it possible to survey not just the likelihood of accomplishing a desired level of wellbore stability at a particular mud weight, but also the impacts of the uncertainty in each single parameter on the wellbore stability. This methodology was implemented to a case study. The most important parameters have been recognized using a sensitivity analysis approach in which the outcome of this QRA procedure suggests the mud weight window with likelihood of well drilling success which can elude the wellbore collapse and lost circulation events. This sort of stochastic approach to deal with anticipated safe mud weight window can guarantee stable wellbore with considerable cost viability associated with drilling success. The technique built up in this paper can give the scientific foundation for assessment of wellbore stability under complicated geological circumstances. It was likewise noted that based on sensitivity analysis, uniaxial compressive strength and maximum horizontal stress are the most effective parameter in estimation of mud weight window. This accentuates the significance of trustworthy determinations of these two parameters for safe drilling of the future wells in the field.

Enze WANG, Guoyong LIU, Xiongqi PANG et al.

The reservoir properties, diagenetic features and evolution of the Paleogene Shahejie Formation (Es) in the Nanpu sag, Bohai Bay Basin were analyzed based on mineralogical and petrological data, and the main controlling factors and formation mechanisms of medium to deep high-quality reservoir were revealed by multiple regression analysis. The results show that the sedimentary microfacies, rigid grains content, and dissolution process are the key factors controlling the formation of high-quality clastic reservoir in middle to deep depth in the Nanpu sag. The formation mechanisms of middle to deep sandstones of the Es in different structural belts differ widely in formation mechanism. The Es1 (uppermost member of Es) sandstone reservoirs in the Nanpu No.3 structural belt is low porosity, moderate to high permeability reservoir in the mesodiagenesis A2 stage on the whole, and the formation of high-quality reservoirs is mainly attributed to strong compaction resistance ability primarily, and dissolution process secondarily. The Es3 (third member of Es) sandstones in Gaoshangpu structural belt is classified as tight sandstones in the mesodiagenesis A1 stage, in which the development of favorable reservoirs is primarily controlled by dissolution. This study provides references for reservoir evaluation of deep clastic reservoirs and exploration deployment in the Bohai Bay rift basin. As there are high-quality reservoirs, it is believed that the deep clastic reservoirs in the eastern of China, such as Bohai Bay Basin still have significant exploration potential. Key words: middle to deep clastic reservoir, high-quality reservoir, diagenetic evolution, Nanpu sag, Bohai Bay Basin, Shahejie Formation

Fengrui Sun, Yuedong Yao, Xiangfang Li et al.

Abstract Huge amount of works was done on modeling of gas transport in nanopores (both organic and inorganic) of shale formation. However, the study on oil transport behaviors is quite limited. Based on the study on water transport in carbon nanotubes, an analytical model is developed for oil transport in nanopores of shale formation. The new model takes the effect of oil–wall interaction on the oil viscosity in the adsorption region into consideration. Results show that: (1) the oil–wall interaction on oil viscosity in the adsorption region plays an important role in oil transport behaviors and cannot be neglected; (2) when the critical thickness is smaller than 1 nm, the volume flux increases slowly with increasing contact angle; (3) when the critical thickness increases to 2 nm, the volume flux increases rapidly to infinity when the contact angle is larger than 140°.

Zeai Wang, Jianjun Tian, Xiaozhu Huang et al.

Hydroprocessing has become the main technology for the production of API Group II and III base oils. One of the key properties is viscosity index for Group II and III base oils. The effect of wax content in hydrocracker unconverted oil on viscosity index and yield was studied in a 400 kton/year hydroisomerization dewaxing plant at a total pressure of 15 MPa, a feed rate of 38 ton/hour, and a gas to oil ratio of 710 Nm³(H₂)/m³(feed). The contribution of wax hydroisomerization to the viscosity index of the main product 150N base oil increases with the wax content in the 11-19% range and reaches a constant value of 6 VI units rather than continuously rising with the wax content. The 150N yield decreases about 1.3%, when the wax content increases by 1%. This is related to a higher dewaxing temperature required at increased wax contents in order to keep the low pour point of 150N, which results in more multi-branched compounds with a low viscosity index in the base oils and more light hydrocracking products.

EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS)

Abstract Chlorophyllins (E 140(i)) are obtained by saponification of a solvent extract from sources, such as grass, lucerne, and nettle, that could not be regarded as edible plant material or food for humans. Chlorophyllins represent 90 % of the colouring matter in the food additive E 140(ii); the remaining part consists of other pigments, such as carotenoids, together with oils, fats and waxes derived from the source material. The Panel noted that the material used in many studies, identified as “chlorophyllins”, was quite often, if not always, a copper complex of chlorophyllins (E 141(ii)). There are no data regarding the absorption, distribution, metabolism and excretion (ADME) and toxicity of chlorophyllins (E 140(ii)). Considering the available data on chlorophylls (E 140(i)), the Panel concluded that chlorophyllins are not metabolites of chlorophylls in humans and owing to their differences in physico‐chemical properties, it was not possible to support read‐across for toxicity data between these two compounds. The Panel considered that it is necessary to carefully review the definition and identity of E 140(ii) in order to adequately characterise the food additive E 140(ii)) as used in the market. This will also allow proper assessment of its safety when relevant studies of the compound to which consumers are actually exposed become available. Considering the absence of relevant ADME and toxicity data, and because chlorophyllins (E 140(ii)) are neither natural constituents of the regular diet nor metabolites of chlorophylls in humans, the Panel concluded that it was not possible to assess the safety of chlorophyllins (E 140(ii)) as food additives.

Lei Na, Chang Yulian, Ren Fushen

The dynamic characteristic of gear rack rig hoisting system is an important factor in affecting its working performance.On the basis of dynamic analysis,the single gear and rack meshing dynamical model and the dynamical model of the hoisting system with the multiple gear and rack meshing are established.The effects of the time varying meshing stiffness of gear on the system dynamic response are determined.Through unite-modeling method of Solidwork and ADAMS,the time varying law of gear rack contact force and gear speed under different hoisting system working conditions are analyzed.The result shows that the output speed of hoisting system gear changes over time due to the internal incentives,and has the synchronism impact peak with engaging force.Given the same working condition,the amplitude is greater during tripping in than in tripping out.Both the curve amplitude of gear speed and the contact force increase during tripping in.The study lays a foundation for structure optimization and reliability design of gear rack rig hoisting system.

Astoin Marie-Florence, Champolivier Josiane, Messean Antoine

Ce texte est tiré du rapport « Introduction de variétés génétiquement modifiées de colza tolérantes à différents herbicides : évaluation des impacts agro-environnementaux et propositions de scénarios de gestion » établi par le Cetiom dans le cadre du moratoire sur les variétés génétiquement modifiées de colza. Les auteurs se réservent la possibilité d’ici publication définitive du rapport d’apporter des modifications à ce texte.

Delseny Michel, Verdoucq Lionel, Maisonneuve Sylvie et al.

Il existe dans les bases de données publiques une énorme quantité de séquences d’ADN dérivées de plantes, et notamment la séquence complète du génome d’Arabidopsis thaliana, une plante modèle pour les oléagineux, proche parente du colza. Ces données constituent une ressource importante non seulement pour la compréhension de métabolisme lipidique et de sa régulation, mais aussi pour la sélection et le développement de variétés nouvelles d’oléagineux produisant davantage d’huiles ou des huiles de composition nouvelle. Cette abondance de séquences peut être exploitée, en utilisant les recherches d’homologies, pour identifier les gènes, pour obtenir des informations sur leur fonction, comme pour repérer des gènes candidats codant des fonctions nouvelles. L’analyse de ces bases de données a révélé que la majeure partie des gènes codant des enzymes impliquées dans le métabolisme lipidique appartient à des petites familles multigéniques, reflétant la diversification des fonctions des isoformes. Une analyse du catalogue des ADNc séquencés en aveugle reflète les niveaux d’expression des différents gènes et fournit un aperçu des régulations des flux au travers des voies métaboliques conduisant à la biosynthèse des lipides de réserve. La disponibilité de mutants et de lignées transgéniques d’Arabidopsis et le développement de puces à ADN qui permettent l’analyse simultanée de plusieurs milliers de gènes conduiront à une meilleure compréhension des facteurs qui régulent le métabolisme des huiles dans les graines. Une telle connaissance facilitera la manipulation de la composition des huiles et des quantités produites dans les graines.