Insight into the oxidative desulfurization of high-sulfur petroleum coke under mild conditions:a journey of vanadium-substituted Dawson-type phosphotungstic acid

High-sulfur petroleum coke(HSPC),that is a by-product from slag oil in the coking process of refning,shows versatility values in practical applications and,however,concentrates the majority of organic sulfur.Herein,we design and construct a highly efective CTAB@HPA composites to be explored for the catalytic oxidative desulfurization of HSPC under mild conditions using hydrogen peroxide as the oxidant and 1-butyl-3-methylimidazole tetrafuoroborate ionic liquid as the extractant.The results demonstrate that the sulfur content of HSPC could be strikingly reduced from 4.46 wt%to 2.48 wt%under 60℃ and atmospheric pressure,and that the organic sulfur in HSPC is mainly oxidized to sulfoxide,sulfone and sulfate,which latter can be directly separated from petroleum coke.Moreover,the efect of reaction conditions on the desulfurization performance of HSPC as well as the catalytic oxidation reaction kinetic of HSPC desulfurization was systematically investigated.Furthermore,a mechanism for the oxidative desulfurization of HSPC over CTAB@HPA catalysts was proposed.Therefore,this work provides new insight into how to construct active catalysts for the desulfurization of HSPC under mild conditions.

Digestion mechanism and crystal simulation of roasted low-grade high-sulfur bauxite

Low-grade high-sulfur bauxite was pretreated via suspension roasting and muffle furnace roasting to remove sulfur and enhance digestion properties.The results show that sulfur can be efficiently removed,and the alumina digestion properties are significantly improved after suspension roasting.Under optimal conditions(t=70 min,T=280°C,w(CaO)=8%and Nk=245 g/L),the digestion ratios are 94.45%and 92.08%for the suspension-roasted and muffle-roasted ore,respectively,and the apparent activation energies are 63.26 and 64.24 kJ/mol,respectively.Two crystal models were established by Materials Studio based on the XRD patterns.The DFT simulation shows that the existing Al—O bands after suspension roasting can improve alumina digestion.The(104)and(113)planes of Al2O3 after suspension roasting are found to combine with NaOH more easily than those of Al2O3 treated in a muffle furnace.

Speciation and thermal transformation of sulfur forms in high-sulfur coal and its utilization in coal-blending coking process:A review

The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur,high-quality coal resources,and sulfur removal from high-sulfur coal is the most important issue.This paper reviews the speciation,forms and distribution of sulfur in coal,the sulfur removal from raw coal,the thermal transformation of sulfur during coal pyrolysis,and the sulfur regulation during coal-blending coking of high organic-sulfur coals.It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization,which raises the need of a combination of current or newly adopted characterization methods.Different from the removal of inorganic sulfur from coal,the organic sulfur can only be partly removed by chemical technologies;and the coal structure and property,particularly high-sulfur coking coals which have caking ability,may be altered and affected by the pretreatment processes.Based on the interactions among the sulfur radicals,sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char,regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry.An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested.That is,the high volatile coals with an appropriate releasing temperature range of CH4 overlapping well with that of H2 S from high organic-sulfur coals is blended with high organic-sulfur coals,and the C–S/C–C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogencontaining radicals generated from high volatile coals.Wherein,the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend.

Geochemical Characterization and Origin of High-Sulfur,Heavy Oils in Jiyang Sub-Basin,East China

High-sulfur,heavy petroleum is widely occurring in the Tertiary lacustrine Jiyang sub-basin, Bohai Bay Basin.They are differentiated into two families based on the bulk properties and biomarker compositions.Family 1 is characterized by high resins（40%-71%）and sulfur（2%-4%）,and low wax （l%-6%）,with n-alkanes removed by biodegradation,whereas family 2 is characterized by extremely abundant sulfur（3%-10%）,and high asphaltenes（7%-31%）and wax（2%-19%）,with no evidence of microbial attack.The oils of family 1 are distributed in the reservoir,lower than 1500 m throughout the sub-basin.Biomarker assemblages,such as low pristane/phytane ratios（1 Pr/Ph）and a high abundance of carotane,gammacerane,and dinosterane,suggest that they are derived from the calcareous mudstones and shales among the stratified,saline Es_4~u unit,in addition to the in situ biodegradation-concentrated sulfur content.However,the oils of family 2 are identified only in the western Zhanhua and eastern Chezhen depressions,with a depth deeper than 1700 m.Physical properties,together with biomarker ratios,including even-numbered n-alkanes,1 Pr/Ph,trace diasteranes,higher C35 homohopanes,and abundant dibenzothiophene series,with1 dibenzothiophene/phenanthrene,indicate an origin from carbonate source rocks.The X-ray diffraction analysis showed that the carbonate source rock is limited in the Es_4~u unit of the Bonan sag,which is different from most other source rocks in the same horizon.It is suggested that the high-sulfur,heavy oils are generated at the early stage of the oil window.Bacterial sulfate reduction might be responsible for the occurrence of sulfur species in the high-sulfur,heavy oils,while heavy biodegradation will enhance sulfur concentrations.

Removal and recovery of titanium(Ⅳ) from leach liquor of high-sulfur bauxite using calcium alginate microspheres impregnated with di-(2-ethylhexyl) phosphoric acid

In the leaching solution of high-sulfur bauxite roasted by sulfuric acid,a high concentration of aluminum presented along with titanium and iron.The present work was to remove Ti(IV)from the leach liquor by calcium alginate microsphere sorbent material(CA-P204)based on natural alginate impregnated with di-(2-ethylhexyl)phosphoric acid(D2EHPA)to purify leaching solution.Cation exchange and chelation make major contributions to the adsorption mechanism according to Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis.The results showed that Ti(IV)was successfully removed by the CA-P204 adsorbent from the Ti(IV)-Al(III)-Fe(III)ternary system with a dynamic column experiment.The removal rate of titanium was nearly 95%under optimal conditions and the maximum adsorption capacity was 66.79 mg/g at pH 1.0.Reusability of CA-P204 was evaluated over three consecutive adsorption/desorption cycles.The adsorption process was simple,low-cost,and had no waste discharge,suggesting that the CA-P204 was promising,efficient,and economical for removing Ti(IV)from high-sulfur bauxite leaching solution.

Multi-objective optimization of high-sulfur natural gas purif ication plant

There exists large space to save energy of high-sulfur natural gas purification process.The multi-objective optimization problem has been investigated to effectively reduce the total comprehensive energy consumption and further improve the production rate of purified gas.A steady-state simulation model of high-sulfur natural gas purification process has been set up by using ProMax.Seven key operating parameters of the purification process have been determined based on the analysis of comprehensive energy consumption distribution.To solve the problem that the process model does not converge in some conditions,back-propagation(BP)neural network has been applied to substitute the simulation model to predict the relative parameters in the optimization model.The uniform design method and the table U21(107)have been applied to design the experiment points for training and testing BP model.High prediction accuracy can be achieved by using the BP model.Nondominated sorting genetic algorithm-II has been developed to optimize the two objectives,and 100 Pareto optimal solutions have been obtained.Three optimal points have been selected and evaluated further.The results demonstrate that the total comprehensive energy consumption is reduced by 13.4%and the production rate of purified gas is improved by 0.2%under the optimized operating conditions.

Problems Encountered and Countermeasure Adopted During Processing of Shengli High-sulfur and High-acidity Crude

The centralized processing of high-sulfur and high-acidity crude has contributed to improvement of the overall economic benefits of the oil refining enterprise, but has also resulted in crude emulsification, severe corrosion of process units and environmental protection issues. The long-cycle, safe and smooth operation of process units were guaranteed after selection of optimal processing routes and adoption of a series of technical measures.

World Bank's Financial Aid to Sichuan Gasfield

World Bank offered 255 million RMB Yuan bank loan and 10 million RMB Yuan donation in equivalent US dollars to"Sichuan Natural Gas Development and Energy-saving Project".This project includes evaluation and development of 13 gasfields and gas-bearing structures in the east-ern Sichuan,reformation of low-permeability gas fields,reformation and expanding of gas pipeline system and related environmental protection in Moxi,Bajiaocang in Middle Sichuan,technical assistance and personnel training,etc.The loan period is limited to 20 years,including five years of extension period.

苏里格气田气井增产挖潜技术对策

本文根据苏里格气田地质特征及气井生产情况分析了气井增产挖潜的必要性,从储层、积液、井筒、地面四个方面对增产技术进行研究分析,提出了16项增产挖潜技术系列,从多个角度全方位对挖潜技术进行介绍,有效地解决了苏里格气田低产气井增产挖潜难题,保障了低产气井系统化、规模化评价挖潜实施。

东胜气田致密高含水气藏合采气井效果评价及产出影响因素分析

为了确定鄂尔多斯盆地北缘致密高含水气藏合采气井开发效果,指导同类型气藏合采气井高效开发。以东胜气田致密高含水气藏为研究对象,分析了单采井与合采井不同开发阶段、不同井区及纵向上的产出效果,以及合采井层间含气性差异对合采井产出的影响,明确了东胜气田致密高含水气藏合采井的开发效果及层间产出的影响因素。研究结果表明:①东胜气田致密高含水气藏合采井具有初期压力高、产量高的特征,但整体开发效果与气藏含气性或产水情况有相关性;②通过参数对比分析,合采井生产层产出效果与产层物性、含气性具有明显的正相关性,产层之间的含气性差异也会影响合采开发效果;③合采井稳定生产临界携液(携泡)流量与气井水气比也具有一定的相关性。结论认为:①东胜气田致密高含水气藏合采井初期压力、产量较高,但在低含气饱和度(高水气比)区域合采井整体开发效果较差,同时气田合采井随着开发时间的推移纵向上层间的产出状况也不断发生变化;②合采气井生产层物性、含气性越好,生产层的产出效果越好,且以物性条件为主导,但在较大的层间含气性差异下,合采井层间易发生严重的气液倒灌使得整体开发效果变差;③合采气井水气比越高,稳定生产临界携液(携泡)流量越大。

东胜气田致密高含水气藏合采气井层间干扰影响因素

为了明确鄂尔多斯盆地北缘致密高含水气藏合采气井层间干扰及其影响因素,指导同类型气藏合采气井高效开发,以该盆地北缘东胜气田致密高含水气藏为研究对象,分析了储集层地质条件、储集层改造对合采井产层段贡献的影响,指出了该类合采气井层间干扰的主控因素。研究结果表明:(1)合采井各产层段贡献率主要受各产层段的孔隙度、渗透率及含气饱和度控制,其产层段孔隙度占主导地位;(2)储层压裂改造对于提高气井产量具有较大的作用,但对合采井各产层段的贡献率却很小;(3)对于致密高含水气藏而言,含气饱和度是合采井产层段贡献率及层间干扰的一个重要影响因子;(4)合采井各产层段之间的孔隙度级差、渗透率级差及含气饱和度级差直接影响着合采井层间干扰程度。结论认为:(1)合采井产层段的孔隙度越大、渗透性越好、含气饱和度越高,则产层段的产量贡献率越大;(2)合采井孔隙度、渗透率及含气饱和度3个参数的级差越大,层间干扰程度越大,当孔隙度级差大于1.248或渗透率级差大于2.69或含气饱和度级差大于1.22时,合采井层间干扰已经非常严重,亟需开展治理。

西南油气田CCUS/CCS发展现状、优势与挑战

中国石油西南油气田公司(以下简称西南油气田)是中国西南地区首个天然气年产量超400×10^(8) m^(3)的油气生产企业,其天然气新建产能、产量的增量分别占到全国增量的1/4和1/3,预计2030年天然气开发的碳排放量将突破500×10^(4) t。为解决天然气高质量上产过程中碳排放量刚性增长的问题,西南油气田主动围绕“天然气+CCUS”的战略规划,积极部署CCUS/CCS工作,以期打造“绿色能源西南模式”,助力实现“双碳”目标。为此,系统阐述了西南油气田在CCUS/CCS业务规划、标准体系、技术系列等方面的发展现状,梳理了其CCUS/CCS业务在资源、技术方面的优势,并分析了面临的技术成熟度不高、经济效益缺乏、社会接受度不高等挑战,最后作出了展望并有针对性地提出了下一步建议:①攻关形成具有气田特色的CCUS/CCS技术体系,打造气田CCUS/CCS原创技术策源地;②建立气田CCUS/CCS标准体系,推广应用气田CO_(2)驱气提高采收率(CCUS-EGR)和CO_(2)埋存技术;③依托西南油气田自有碳捕集、输送、驱气、封存等技术,进一步延伸拓展传统油气主营业务产业链,建立西南片区CCUS/CCS产业集群和碳库,助力中国石油成为CCUS/CCS产业链链长;④探索页岩气注CO_(2)及混合气体提高采收率技术,支撑在页岩气领域开辟新的CCUS方向。

东胜气田独贵气区高含水致密砂岩气藏气井合理工作制度

为了有效支撑高含水致密砂岩气藏高效开发,以鄂尔多斯盆地东胜气田独贵气区为研究对象,在研究高含水致密砂岩气井不同水气比条件下产出特征的基础上,分析了应力敏感及生产压差对气井产出的影响,评价了不同配产工作制度下气井的产出效果,提出了气井差异化配产方案及压降速率控制标准。研究结果表明:①研究区气藏储层孔喉组合以微孔细喉为主,具有低孔隙度—特低孔隙度、致密低渗透及强非均质性的特征;②高含水致密砂岩气藏气井开发效果受产水量影响较大,气井水气比越高,产气量递减越大、压降速率越快、弹性产率越低;③随着生产压差不断扩大,造成部分毛细管水和束缚水膜变成可动水,气井产水量增加,弹性产率变低,累计产气量减小,稳产难度增大,开发效果变差。结论认为:①对于衰竭式开发的高含水致密砂岩气藏,控制气井的配产和压降速率是延长气井稳产期、提高天然气采收率的重要手段;②所建立的高含水致密砂岩气藏气井差异化配产方案和气井压降速率控制图版在生产实践中证明符合率达到87.5%,可推广应用于同类型气藏的开发开采,更好地指导气井效益开发。

延安气田延长东地区盒8段致密气藏储层特征研究

为深化延安气田延长东地区致密气藏地质认识,对研究区盒8段储层开展了岩石学、物性和孔隙结构特征研究,并对物性主控因素进行了分析。结果表明:1)砂岩类型以岩屑石英砂岩为主,碎屑组分以石英为主,黏土矿物以绿泥石和伊利石为主,脆性指数和成分成熟度较高,孔渗呈强指数正相关和不对称双峰状分布,平均孔隙度为5.3%,平均渗透率为0.101×10^(-3)μm^(2),有效物性下限孔隙度为2.3%、下限渗透率为0.035×10^(-3)μm^(2),渗透率主要受宏孔隙控制;2)平均喉道半径为0.41μm,平均孔隙半径为135.38μm,原生孔隙空间损失较大,孔隙半径、有效孔隙体积和孔喉比为储集空间的主控因素,有效喉道体积为渗流能力的主控因素,储层孔隙结构分为Ⅰ类优质储层、Ⅱ类一般储层和Ⅲ类较差储层;3)储层物性主要受强压实作用、弱胶结作用和弱溶蚀作用控制,初始孔隙度为36.81%,视压实率为71.83%,压实作用减孔量为26.44%,视胶结率为24.50%,胶结作用减孔量为9.02%,视溶蚀率为9.48%,溶蚀作用增孔量为3.49%。该研究成果可为研究区乃至延安气田致密气藏高效勘探开发提供一定的地质依据。

气田采出水处理关键技术研究

气田采出水存在产出量大、水质复杂、乳化严重等问题,同时气区集气站分布广、距离远,采出水的运输和处理难度较大。为进一步提升采出水运输效率、优化水质指标,强化除油效果,挖掘轻烃增产潜力,全面推行“拉运-管输”工艺改造,优选液压单缸双作用柱塞泵保障输送效率,攻关形成了“破乳+油水分离+气浮+旋流分离”水处理工艺,同时开展油水混输及药剂配伍效果试验,评价工艺运行效果。研究表明:(1)在采出水管输工艺改造基础上,采用集气站-处理厂油水混输模式,可有效提高生产效率,减轻员工劳动强度,降低生产运行成本;(2)采用油水混输,经过“前端破乳+油水分离”工艺处理,可强化油分分离效果,产油率较单一的大罐沉降处理模式提升4.73%;(3)结合“破乳+油水分离+气浮+旋流分离”工艺,按照水处理量60 m^(3)/h,确定了最佳加药类型7种、加药顺序、加药数量等影响水处理效果的关键因素,处理后水质悬浮物去除率为64%,油分去除率为92%。

临兴气田致密砂岩储层可动流体分布特征及主控因素

针对鄂尔多斯盆地临兴地区储层微观孔隙结构复杂、可动流体分布特征及控制因素不明等问题,综合利用低场核磁共振、场发射扫描电镜、X射线衍射分析、核磁共振成像以及CT扫描等手段,对临兴气田上石盒子组和太原组可动流体饱和度特征进行定量刻画,分析了孔隙度、渗透率、岩石矿物组成、微观孔隙连通性与可动流体饱和度之间的关系。结果表明:临兴地区石盒子组储层平均可动流体饱和度为58.05%,太原组储层平均流体饱和度为48.60%,石盒子组储层平均流体饱和度明显高于太原组;渗透率及孔隙连通百分比是影响致密砂岩储层可动流体饱和度的重要因素。研究结果可为临兴致密砂岩储层渗流规律认识及开发方案编制提供有力支撑。

电磁涡流内检测技术在含硫双金属复合管道的应用研究

含硫气田集输管道因输送天然气成分及输送成分复杂,管道内壁可能会发生电化学腐蚀,因此对酸气管道开展腐蚀检测十分重要。常规的漏磁检测技术因无法磁化双金属复合管的非铁磁性内衬管而不适用,电磁涡流检测技术利用电磁感应原理及趋附效应对管道内表面缺陷检测敏感性强、检出率高,涡流内检测器在管道中通过性好,可用于多种运行管控。本文结合电磁涡流内检测技术在某含硫气田双金属复合管的首次应用,阐述涡流内检测技术的基本原理,总结其优势和局限性,验证其在现场的适应性,为其今后在含硫气田双金属复合管道内检测中推广应用提供借鉴。

低渗含硫气藏开发后期井筒化学解堵工艺——以磨溪雷一1亚段气藏为例

磨溪雷一1亚段气藏(简称“磨溪雷一^(1)气藏”)属低渗透碳酸盐岩中高含硫气藏,为了解决气藏开发后期地层压力低、井筒堵塞严重导致气井低产甚至停产的难题,进行了井筒化学解堵工艺措施的研究。在分类统计低压气井井筒堵塞现状的基础上,分析堵塞机理,优选解堵剂,并选择磨溪雷一^(1)气藏的典型堵塞气井,开展化学解堵现场试验。针对气井低压特征,优化关键工艺参数,最终形成井口泵注解堵剂、连续油管解堵剂冲洗两套化学解堵工艺措施,适用于堵塞程度不同的气井。研究结果表明:(1)磨溪雷一^(1)气藏井筒堵塞物主要由烃类、酯类组成的有机物和由FeS、Fe_(3)O_(4)等组成的无机物构成,大部分堵塞物来源于井下工具及管材的腐蚀产物;仅无机解堵剂对堵塞物有溶解分散作用,其中CT4-12B性能最优。(2)井口泵注解堵剂工艺,适用于井筒内有一定流动通道的中、轻度堵塞井以及堵塞井段较短的重度堵塞井;解堵剂加注量0.5 m^(3)、浸泡时间24 h时,效果最佳。(3)连续油管解堵剂冲洗工艺,能够有效解除井筒重度堵塞,但井筒造斜点以下施工难度增大;解堵剂加注量1 m^(3)、直井段浸泡时间3 h、斜井段浸泡时间24 h时,效果最佳。两种井筒化学解堵工艺在磨溪雷一^(1)气藏的现场应用试验结果,4口中度堵塞井、8口重度堵塞井共计12口气井实现解堵,日增产气量共计24.1×10^(4)m^(3),取得较好效果,表明两种井筒化学解堵工艺切实可行,对同类气藏具有一定借鉴意义。

米脂气田太原期古地貌对砂体的控制作用

鄂尔多斯盆地米脂气田太原组砂岩是致密气藏的主力产层,但砂体横向变化快。研究表明:古地貌是控制砂体沉积的重要因素,决定着砂体发育位置及分布规模。基于三维地震资料,结合完钻井数据,运用印模法与沉积学综合分析相结合的方法,采用三维地震地层水平切片、多属性融合技术,通过沉积厚度求取,恢复米脂气田二叠系太原组沉积期的古地貌,分析古地貌对三角洲前缘砂体及油气的控制作用,进而通过地震属性和神经网络技术预测太原组有利砂带的分布规律。研究成果优化井位部署,新井钻遇太原组砂岩的符合率达到90%,进一步证实了基于古地貌的储层预测技术的可靠性,对米脂气田的效益开发具有重要的指导意义。