Effects of Temperature and Catalyst to Oil Weight Ratio on the Catalytic Conversion of Heavy Oil to Propylene Using ZSM-5 and USY Catalysts

It is useful for practical operation to study the rules of production of propylene by the catalytic conversion of heavy oil in FCC （fluid catalytic cracking）. The effects of temperature and C/O ratio （catalyst to oil weight ratio） on the distribution of the product and the yield of propylene were investigated on a micro reactor unit with two model catalysts, namely ZSM-5/Al2O3 and USY/Al2O3, and Fushun vacuum gas oil （VGO） was used as the feedstock. The conversion of heavy oil over ZSM-5 catalyst can be comparable to that of USY catalyst at high temperature and high C/O ratio. The rate of conversion of heavy oil using the ZSM-5 equilibrium catalyst is lower compared with the USY equilibrium catalyst under the general FCC conditions and this can be attributed to the poor steam ability of the ZSM-5 equilibrium catalyst. The difference in pore topologies of USY and ZSM-5 is the reason why the principal products for the above two catalysts is different, namely gasoline and liquid petroleum gas （LPG）, repspectively. So the LPG selectivity, especially the propylene selectivity, may decline if USY is added into the FCC catalyst for maximizing the production of propylene. Increasing the C/O ratio is the most economical method for the increase of LPG yield than the increase of the temperature of the two model catalysts, because the loss of light oil is less in the former case. There is an inverse correlation between HTC （hydrogen transfer coefficient） and the yield of propylene, and restricting the hydrogen transfer reaction is the more important measure in increasing the yield of propylene of the ZSM-5 catalyst. The ethylene yield of ZSM-5/A1203 is higher, but the gaseous side products with low value are not enhanced when ZSM-5 catalyst is used. Moreover, for LPG and the end products, dry gas and coke, their ranges of reaction conditions to which their yields are dependent are different, and that of end products is more severe than that of LPG. So it is clear that maximizing LPG and propylene and restricting dry gas and coke can be both achieved via increasing the severity of reaction conditions among the range of reaction conditions which LPG yield is sensitive to.

Feasibility study on buoyancy-weight ratios of a submerged floating tunnel prototype subjected to hydrodynamic loads

The research progress of a novel traffic solution,a submerged floating tunnel（SFT）,is reviewed in terms of a study approach and loading scenario.Among existing publications,the buoyancy-weight ratio（BWR） is usually predefined.However,BWR is a critical structural parameter that tremendously affects the dynamic behaviour of not only the tunnel tube itself but also the cable system.In the context of a SFT prototype（SFTP） project in Qiandao Lake（Zhejiang Province,China）,the importance of BWR is illustrated by finite element analysis and subsequently,an optimized BWR is proposed within a reasonable range in the present study.In the numerical model,structural damping is identified to be of importance.Rayleigh damping and the corresponding Rayleigh coefficients are attained through a sensitivity study,which shows that the adopted damping ratios are fairly suitable for SFTP.Lastly,the human sense of security is considered by quantifying the comfort index,which helps further optimize BWR in the SFTP structural parameter design.

Development of High Viscous Oil in Sandstone Reserviors During the High Water Cut Stage，Gudao Oilfield

The oi!bearing area of Gudao Oilfield covers 80.9 square kilometers.with 373 million tons of oil in place.It is a large drape anticlinal.Neogene Gu-dao Formation is main oil-beraing reservoir devel-oped with dip gentle from 30'to 1°30'in general.The main oil-bearing sequences can be divided into 6 sand groups and 34 layers in detail.in which the Ng°-Ng°sand groups are the main payzones in which oil in place accounts for 97.2%of the total.

Study on Flow Unit of Heavy Oil Bottom Water Reservoir with Over-Limited Thickness in Offshore Oilfield

The upper Ming section of L oilfield is a typical offshore heavy oil bottom-water reservoir with thick fluvial layers. All horizontal wells are developed by natural energy. Due to the few drilling holes and influence by the resolution of seismic data, it is difficult to describe reservoirs with thickness over 20 meters. In this paper, seismic resonance amplitude inversion technology is introduced to restore the real response of thick reservoirs and interbeds by drilling and drilling verification, and the geological bodies with different thickness are displayed by frequency division RGB three primary colors. Flow units of heavy oil reservoirs with bottom water are divided according to the three major factors of interlayer, lithologic internal boundary and water-oil thickness ratio which have the greatest influence on horizontal well development, thick sand bodies are divided into 10 different flow units in three levels, each unit is separated from each other, and the reservoir structure, water-cut characteristics and water-flooding characteristics are different. The reliability of the research is improved by using the dynamic data of horizontal wells and newly drilled passing wells, which provides a basis for tapping the potential of heavy oil reservoirs with bottom water.

Developing High Water-cut Oil Fields Deeply to Enhance Their Oil Recovery

In order to recognize the distribution of dispersed remaining oil,reservoirs should be described in more detail and quantitatively to establish refined and sophisticated 3D quantified reservoir model which can reflect the detailed variation in the reservoir and its structure.The key point of sophistication and quantification of reservoir characterization is to describe the geo-metry of interwell sandbodies and to estimate their reservoir parameters.

Developing High Water-cut Oil Fields Deeply to Enhance Their Oil Recovery

As stated above,the ultimate recovery of conventional oil in our country is estimated to be 33.6%,i.e,about 66.4%of the oil reserves cannot be recovered by water injection and may only be targeted for tertiary oil recovery or for other ty pes.of new technologics.A screening of 82 major oifields developed by water injection and an analysis of their potential showed that application of tertiary recovery technique such as polymer flooding,surfactant flooding and gas miseible flooding will inerease the oil recovery by 12.4%.The total recoverable reserve increment cor-responds to 56%of the current remaining recover-able reserves.This means that the recoverable r'eserves in OUr country can increase by more than one half by a fully tapping of the potential.Therefore,the development of tertiary recovery technology will be an important strategic measure in China's petroleum industry.

Mitigation effects on the reflected overpressure of blast shock with water surrounding an explosive in a confined space

The mitigation of blast shock with water has broad application prospects. Understanding the mitigation effects on the reflected overpressure of the explosion shock with water surrounding an explosive in a confined space is of great significance for military explosives safety applications. To estimate the effects of the parameters on the reflected overpressure of blasted shock wave, a series of experiments were carried out in confined containers with spherical explosives immersed in a certain thickness of water,and numerical simulations were conducted to explore the corresponding mechanisms. The results reveal that the reflected overpressure is abnormally aggravated at a small scaled distance. This aggravation is due to the high impulse of the bulk accelerated water shell converted from the explosion. With increasing scaled distance, the energy will be gradually dissipated. The mitigation effects will appear with the dispersed water phase front impacting at a larger scaled distance, except in the case of a dense water phase state. A critical scaled distance range of 0.7-0.8 m/kg^(1/3) for effective mitigation was found. It is suggested that the scaled distance of space walls should be larger than the critical value for a certain water-to-explosive weight ratio range(5-20).

Complicated water-oil distribution and water out in high permeable fracture and cave system,but relatively good oil-bearing condition presents in low permeable ones

According to drilling core analysis and a lot of.field information,it was proved that the current reservoir range above oil-water contact detected by observation wells,was no more a complete pure oil bearing zone with exception of water cone,but a complicated oil-water mixed zone.The oil,satura-tion in the fracture system varied greatly.The large fractures with width of over 100μm were al-most water flushed,the middle fractures between 50-100μm were water encroachment zone and the small fractures less than 50μm were still in a good oil-bearing condition.

The Colored Oil Property Effect on Switching Behavior of Electro-Fluidic Display

The switchable oil layer driven by electrowetting gives visible color and light valve control, which is the basis of Electro-Fluidic Displays. The colored oil’s property is a key factor that influences the Electro-Fluidic Displays switching behavior. A purple oil was formulated by the oil-soluble purple dye in decane in this study. The dye molecule itself is nonpolar and it doesn’t dissolve in water. The concentration of colored oil influenced the oil/water interfacial tension and oil viscosity. The relationship of EFD switching behavior with oil/water interfacial tension, oil viscosity, and oil conductivity has been systematically investigated. The oil/water interfacial tension decreased with increasing oil concentration, in the meanwhile, the conductivity increased. Oil conductivity was one of the key factors that influenced the Electro-Fluidic Displays optical property. We found for the first time that at the lower oil concentration (2% - 10%), the interfacial tension plays a main role effect on the rupture voltage and response time, but as the conductivity of higher concentration of colored oil increased (at 20%), the rupture voltage-controlled both by conductivity and interfacial tension.

Correlation between hydrocarbon distribution and water-hydrocarbon ratio in Fischer-Tropsch synthesis

In order to shorten the evaluation cycle of cobalt catalyst before the optimized catalyst is fixed on, a mathematical method is proposed to calculate weight percentage of C5＋ hydrocarbons. Based on the carbide polymerization mechanism and the main hydrocarbons being linear alkanes and α-olefins, the correlation between hydrocarbon distribution and the molecular mass ratio of water to hydrocarbons is discussed. The result shows the ratio was within the range of 1.125-1.286 and the lower the ratio, the more gaseous hydrocarbons were obtained. Moreover, a linear equation between the weight percentage of C5＋ hydrocarbons and the weight ratio of C5＋ hydrocarbons to the total water is established. These results are validated by corresponding experiments. The weight percentage of C5＋ hydrocarbons could be immediately calculated by this linear equation without detailed gas chromatography （GC） analysis of them.

Diagnostic Method and Adaptability Analysis of Multiple Water Breakthroughs in Horizontal Well in Combined Well Pattern

The combined well pattern has been widely used in reservoir development, with a common pattern being a horizontal well in the center for oil production and multiple vertical wells around for water injection. For this type of well pattern, determining the horizontal well is affected by which injection wells, especially when the injecting water breaks through, accurately determining the direction of water inflow will provide an important basis for targeted water well measures. Based on the production performance data of horizontal wells, the semi logarithmic relationship curves of water-oil ratio, derivative water-oil ratio, and cumulative production were used for the first time to determine the breakthrough problem of water injection in the surrounding water injection wells of horizontal wells based on their response characteristics. The adaptability of this method under different influencing factors was analyzed. Introducing the parameter of cumulative production not only preserves the variation trend of the derivative of water-oil ratio with time, but also facilitates the processing of actual production data.

A new approach of proration-injection allocation for water-flooding mature oilfields

This paper presents a new method of injection-production allocation estimation for water-flooding mature oilfields.The suggested approach is based on logistic growth rate functions and several type-curve matching methods.Using the relationship between these equations,oil production and water injection rate as well as injection-production ratio can be easily forecasted.The calculation procedure developed and outlined in this paper requires very few production data and is easily implemented.Furthermore,an oilfield case has been analyzed.The synthetic and field cases validate the calculation procedure,so it can be accurately used in forecasting production data,and it is important to optimize the whole injection-production system.

Differential Aphid Colony Establishment in <i>Dolichos lablab</i>Varieties Correlated with Some Plant Specific Factors That Impact on Aphid Fecundity

Aphid establishes colony in the selective plant parts like vine, leaf petiole, leaflet, inflorescence, and tender fruit in Dolichos lablab Linn but not the entire plant. In this study, the aphid colony establishment in vine is focused to understand the differential resistance response between two varieties. At the early stage of aphid infestation, the aphid colony establishment was significantly different between two genotypes (p value = 0.00) and abbreviated as “resistant” variety that supported lower aphid proliferation (mean value = 48.2 ± 2.2) and “susceptible” variety that supported comparatively higher aphid proliferation (mean value = 215.5 ± 16.9). The total aphid number was significantly different between the two varieties, realized at the early infestation stage when both “antixenosis” and “antibiosis” defense mechanisms were working on. Some plant specific factors like vine diameter, wet/ dry weight ratio of vine, phloem sap pressure, the compactness of the vine, wet/dry weight ratio of leaflet, length of leaf petiole, diameter of leaflet vein were identified as modulating factors. The impact of resistant variety on aphid was also investigated for better understanding of aphid defense mechanism.

微波含水率检测技术在复杂油水混合形态下的应用研究

在油水混合物中会出现不同的乳化形态,不同的乳化形态对应的电导率和介电常数也具有显著差异,从而导致通过检测电导率和介电常数值间接测量含水率的测量结果不准确。针对复杂油水混合状态下含水率难以测准的问题,提出一种基于微波技术的复杂油水两相流含水率检测技术,建立了基于微波技术的“油包水”和“水包油”状态分析方法。首先通过检测微波信号穿过不同介质后信号幅值的衰减和相位的偏移,推测油水混合物的含水率值。再利用不同输入功率的微波信号在不同介电常数下功率衰减比不同的原理,来区分油水混合物的乳化状态,优化含水率的测量。室内验证和矿场试验结果表明,该系统可有效区分乳化液的混合状态,通过含水率标定值对实测数据进行修正,最终测量的含水率误差可控制在1个百分点以内,实现了复杂油水混合形态下含水率的高精度测量。

断溶体油藏追踪油水界面变化的新方法

在底水驱动型断溶体油藏中确定原始油水界面及追踪动态油水界面变化一直是制约剩余油预测的重要难题。此文聚焦油水界面的油藏本质,精细量化了储集体的孔隙体积,开发动态数据试井化处理计算水油体积比,动静结合等比例分配油水体积计算出原始油水界面。在油藏内部划分出油水界面,后期根据水驱动用过程评估曲线划分水驱阶段,追踪动态油水界面变化,避免陷入前期常规方法选取参数困难、计算误差大的困境。开发实践证实该方法得到的结果误差小,计算方便快捷,具有推广应用前景。

咸淡水组合灌溉对土壤盐分和棉花生长的影响

为揭示不同微咸水(农田排水)与淡水在“先咸后淡”的组合灌溉模式下对土壤容重、盐分迁移和棉花生长的影响。以淡水灌溉为对照(CK),设置7种不同微咸水、淡水组合灌溉(微咸水∶淡水=1∶14(T1)、2∶13(T2)、3∶12(T3)、6∶9(T4)、9∶6(T5)、12∶3(T6)),T7处理采用全额微咸水灌溉,于2022年4-9月进行了棉花田间试验。结果表明,采用微咸水灌溉造成土壤表层盐分积累,0~40 cm土层出现积盐现象,棉花生育期结束后,各处理与淡水对照(CK)比较,T1~T6在0~40 cm土层的电导率分别增加1.16%~26.61%,T7处理电导率增加86.40%;与淡水对照相比,组合灌溉后各处理土层0~40 cm土壤容重明显增加,土壤孔隙度降低,以全额微咸水灌溉T7处理最为显著(容重增加10.24%);微咸水组合灌溉有效提高棉花株高、叶面积指数、茎粗。合理利用微咸水组合灌溉能够为棉花生长提供良好的水盐环境,提高棉花产量,能够为极端干旱区合理利用微咸水提供一种新的灌水模式,为灌区发展节水灌溉及农业可持续发展提供理论支撑。

断控型碳酸盐岩油藏动态储量计算方法

断控型碳酸盐岩油藏非均质性强,不同尺寸的孔、缝、洞交错发育,采用一般物质平衡方法计算的动态储量可能大于静态储量。在引入水油比的基础上,考虑孔缝洞介质不同时的岩石压缩系数,得到了适用于断控型油藏的综合压缩系数,并在此基础上建立了断溶体流动物质平衡新方程,通过数值模拟,验证了新方程的准确性与适用性。结果表明:新方程计算的动态储量与数值模拟得到的静态储量误差仅为0.1099%,验证了新方程准确可靠;哈拉哈塘地区多口井用新方程计算的动态储量与地质建模雕刻的静态储量相对误差为-4.82%~-0.15%,远远低于物质平衡方程计算的动态储量与静态储量的相对误差,新方程计算结果更接近实际情况,更适用于哈拉哈塘地区断控型碳酸盐岩油藏的储量计算。

普通稠油非均相复合体系组分驱油贡献率

非均相复合体系能实现协同调驱,在稠油开发方面极具潜力,但各组分驱油贡献率不明确,给体系优化与选择带来盲目性。针对由部分水解聚丙烯酰胺、双效型表面活性剂和预交联凝胶颗粒(B-PPG)组成的非均相复合体系,在分析其界面与封堵性能和驱油特征的基础上,开展了聚合物、二元复合体系和非均相复合体系驱油实验;依据3类体系驱油的采收率增幅,归一化计算了不同水油黏度比下非均相复合体系组分驱油贡献率。结果表明,0.106~0.150 mm(150~100目)B-PPG膨胀后的粒径中值为800μm。该非均相复合体系与渗透率为1.1μm~2的填砂模型匹配,运移封堵阻力系数与残余阻力系数分别为420.5和203.0,更低渗透率(0.30μm~2)的填砂模型则难以进入。对于渗透率级差约为3.0的并联填砂模型,非均相复合体系具有较强的调驱能力,最高注入压力为0.42 MPa、低渗透模型分流率最高达到42.2%;而二元复合体系的最高注入压力仅为0.25 MPa、低渗透模型分流率仅为24.3%。当水油黏度比为0.05~0.46时,非均相复合体系中聚合物驱油贡献率(43.1%~84.1%)最高,表面活性剂(22.1%~7.6%)最低,B-PPG(34.8%~8.3%)介于两者之间。水油黏度比(≥0.46)较高时,表面活性剂和B-PPG驱油贡献率较小,聚合物或二元复合驱后非均相复合驱增油潜力有限;水油黏度比(≤0.2)较低时,表面活性剂和B-PPG驱油贡献率大,水驱或聚合物、二元复合驱后非均相复合驱增油潜力较大。

电潜螺杆泵入口处气液比动态变化特性分析

随着油田开发的不断深入,螺杆泵采油技术得到进一步发展与完善,近年来,在高含气和稠油等非常规油气藏中也得到广泛应用,但由于游离气和溶解气的存在,气体进入泵内会影响螺杆泵的工作性能和使用寿命。针对这种情况,综合考虑油气水三相流体对螺杆泵运行工况的影响,结合钻井液密度、生产气油比、含水率和气体状态方程,建立了螺杆泵入口处的气液比计算模型,并以大港油田J36-6和J36-8油井的生产数据进行模拟分析。结果表明,在动液面高度一定的情况下,增加下泵深度有利于降低泵入口处的气液比,高密度、高含水和低生产气油比是保证泵入口气液比较低的关键。

低油水比油基钻井液体系研究

现阶段国内大量应用的油基钻井液体系油水比居高不下,且由于部分处理剂性能欠佳导致在钻井液体系中用量过大,两者叠加为降低油基钻井液体系综合成本带来极大困难。为此,提出了低油水比油基钻井液体系设计思路,并以此为指导研选了油基钻井液体系关键处理剂,通过配伍性实验构建了低油水比油基钻井液体系配方,并开展了现场应用。以保障在良好的乳化稳定性、流变性和较强的随钻封堵性基础上有效降低油水比为整体思路,研制了多活性点新型乳化剂,增加了分子内活性吸附基团的数量,在低油水比的情况下表现出良好的乳化稳定性和流变性;优选了具有良好增黏提切效果且可降低滤失量的有机土、具有良好降滤失效果的降滤失剂、具有改善流变性且提高乳化稳定性的流型调节剂,以3种处理剂为核心构建了低油水比油基钻井液体系;该体系在70/30的油水比条件下老化前后破乳电压>1000 V,在60/40的油水比条件下老化前后破乳电压>500 V,动塑比均>0.40,具有良好的乳化稳定性和流变性;低油水比油基钻井液体系在12口页岩水平井开展了现场应用,钻井液体系性能稳定、井眼净化效果良好,且乳化稳定性可控,大幅节约了基础油的用量,显著降低了油基钻井液体系的成本。