不同条件下高硫减渣加氢裂化对比性实验

高硫减渣通过悬浮床加氢裂化装置进行加氢裂化实验研究,文中重点就高硫减渣在不同温度、压力条件下进行对比性实验研究.研究表明随着温度的升高,热裂化反应不断加剧,C1～C4低碳烃的产率相应提高,加氢裂化反应也有一定程度的提高,氢耗也有一定程度的提高;相同温度下提高反应压力有利用加氢裂化反应的发生,进而促进>525℃渣油组分转...     

A kinetic model for pyrolysis of petroleum residue under nonisothermal conditions

Kinetic study on pyrolysis of petroleum residue was carried out by an accurate Arrhenius type equation at heating rate of 0.5–30.0°C/min under nonisothermal conditions. The influence of some critical parameters including temperature, heating rate and activation energy on mass conversion was evaluated. The apparent activation energies for during the pyrolysis process were in the range of 198–361 kJ/mol at various mass conversions of 5–94%. The reaction temperature was introduced as the most important parameter for the improvement of mass conversion, compared to that of other parameters. The pyrolysis of petroleum residue was occurred in a broad temperature range, from 150–650°C, yielding 33 wt% unpyrolyzed residue. It also was found that an increase in heating rate has a minor impact in the process. Model predictions were compared with experimental data, which showed fully good agreement.     

Chlorpyrifos residue levels on field crops (rice,maize and soybean) in China and their dietary risks to consumers

In this study, chlorpyrifos residue levels in field crops of rice, maize and soybean were investigated according to the “Guideline on Pesticide Residue Trials” of China. On the basis of the residual results, human dietary risks were further evaluated. Chlorpyrifos residues of harvest grains were firstly prepared by QuEChERS method and analyzed using Gas Chromatography Tandem Mass Spectrometry (GC–MS/MS). Dietary risks were assessed by a deterministic approach. The median residues in field trials of rice, maize and soybean were 0.617, 0.0227 and 0.0136 mg kg⁻¹, respectively. The highest residues in field trials of rice, maize and soybean were 3.23, 0.114 and 0.102 mg kg⁻¹, respectively. Chronic intake assessment indicated that only 39.0% of acceptable daily intake (ADI, 0–0.01 mg kg bw⁻¹ day⁻¹) was consumed through rice, maize and soybean. The acute hazard indexes (aHI) of adults was 26.1% of acute reference dose (ARfD, 0–0.1 mg kg bw⁻¹) and aHI of children was 63.5% of ARfD in dietary exposure assessment through rice, maize and soybean consumption. Single pathway risk assessment indicated that chlorpyrifos application on field crops in manner of the good agricultural practices didn't pose public health risks.     

流动条件下原油乳化含水率与水相组成的关系

油田采出水中含有大量的无机阴、阳离子,如Na⁺、Ca²⁺、Mg²⁺、Cl^-、HCO₃^-等,这些离子对油-水两相体系的乳化特性有重要影响。以流动条件下原油的乳化含水率表征油-水两相体系的乳化特性,针对以CaCl₂、NaHCO₃、Na₂SO₄、MgCl₂和NaCl共5种盐溶液为水相、存在游离水的高含水油-水两相体系,通过搅拌实验,研究了水相组成对原油乳化含水率的影响。研究表明,这些无机盐的加入可以使原油的乳化含水率增大,但随着矿化度的增大,原油乳化含水率增大的速率逐渐减小;这5种无机盐对流动条件下原油乳化含水率的影响大小排序为:NaCl>(Na₂SO₄、NaHCO₃)>MgCl₂>CaCl₂;酸性环境不利于原油的乳化,而碱性环境能够促进原油的乳化,一定矿化度条件下,pH值越高,其乳化含水率越高。对于一定矿化度下的高含水油-水两相体系,不同剪切条件下的乳化含水率可以与搅拌槽内的黏性流动熵产率进行归一化关联,并且二者符合幂律关系。通过回归分析得到了该幂率关系式中的待定参数与水相组成之间的定量关系式。     

苏里格西区气水分布特征及产水类型解析

利用钻井、测井、生产测试、分析化验资料,运用统计分析、经验公式计算以及相渗-压汞综合分析方法,研究苏里格西区气水分布规律,确定气藏产水类型及其构成.研究结果表明:该区气水分布呈"渐变互补"关系,相对富水区在西北部;地层产出水由凝析水、可动水和自由水构成,控制生产压差即可控制地层产水.该研究为气田产水井管理及开发选区工作...     

复杂条件下油井套管损坏原因及预防措施

在油田开采过程中,尤其是开采中后期,经常发生油井套管损坏现象,严重影响了油田的开发效益.引起油井套管损坏的因素很多,既有地质方面的,也有工程方面的.为了深入了解油井套管损坏的原因,以便采取有效措施保护套管,对地层的地质和井下工程情况进行了综合研究.首先,根据井筒中套管所受的应力场分布和作用机制,针对套管、水泥环、地层为弹性介质和塑性介质2种情况,分别建立了与之相对应的弹性和塑性数学物理模型及射孔后的流固耦合模型;然后,模拟计算分析了射孔、水泥环、地层岩性、注水压力、放喷流量、温度和压力等因素对套管受力的影响.结果表明:水泥环的弹性性质和厚度具有降低套管载荷的作用,地层的塑性和流变性对套管受力影响很大,地层压力的变化会引起套管应力的变化;可采取提高固井质量、确定射孔方向和选择合理的注水压力等措施来预防套管损坏.     

四川盆地安岳特大型气田不同产能状态下龙王庙组的储层特征

下寒武统龙王庙组是安岳特大型气田的主力产气层,认识和刻画其储层特征对勘探开发至关重要。基于对安岳气田不同产能状态下龙王庙组储层的岩性、类型以及不同类型储层的厚度占比和孔洞发育情况的分析,建立高产井、中产井、低产井和干井中储层特征与油气产能的联系,其结果表明:龙王庙组储层主要发育于颗粒白云岩和结晶白云岩层段,储集空间有溶蚀孔洞、粒间溶孔、晶间溶孔和裂缝等,其中,孔洞和孔隙是主要类型;孔洞型储层是安岳气田中龙王庙组高产井的主导储层,其占比、孔洞发育密度、孔洞大小、孔洞段的单层厚度和累计厚度等是影响油气产能的主要因素;孔洞型储层的非均质性强,孔径呈双峰分布,表现为大尺寸(毫米级和微米级)的孔洞和小尺寸(纳米级)的晶间孔、晶间溶孔;孔隙型储层的孔隙分布均匀,孔径呈单峰分布,主要发育微米级孔隙。     

国内天然气分析测试标准掺氢适应性探讨北大核心CSCD

目的确认国内现行的天然气分析测试标准对掺氢天然气分析计算的适应性,以促进掺氢天然气标准化工作。方法通过对国内天然气分析测试标准进行分析,筛选出与掺氢天然气相关的标准共10项,研究了天然气组成分析标准和物性计算标准在掺氢条件下的适应性。结果以GB/T 13610-2020《天然气的组成分析气相色谱法》为代表的天然气组成分析标准和以GB/T 17747.2-2011《天然气压缩因子的计算第2部分:用摩尔组成进行计算》为代表的物性计算标准规定的氢气摩尔分数最高为10%,在高含量氢气的条件下,相关标准需要修订;若管道掺氢后下游氢气不分离,天然气互换性及其标准化亟需研究。结论提出的标准制修订框架对今后掺氢标准化工作思路具有参考意义。     

Analysis of rdx vapors in pre- and postdetonations using the ion mobility spectrometer under field conditions

The purpose of this work was threefold: To determine if the presence of RDX vapors could be detected both before and after an explosion in an enclosed area; to determine if this could be done with an ion mobility spectrometer (IMS) in the field; and to test the concept of using a 6–in. quartz tube (0.25-in. od) as a preconcentrator in the field. All three purposes were fulfilled.     

考虑技术经济条件下的威远页岩气田水平井长度优化

页岩储层水平井合理长度优化对合理开发至关重要.综合考虑技术与经济条件,对威远页岩气田不同长度水平井开发周期内(10 a)的产量、单井投资、经济效益进行详细分析,明确了该区最优经济价值条件下水平井长度范围,讨论了天然气价格、页岩气补贴、建设投资、单井产量对不同长度水平井开发效益的影响.研究结果表明:威远页岩气田高产井比例...     

海上油田水聚干扰影响因素分析及矿场试验研究

水聚交叉井网会造成水聚干扰现象,导致聚驱效果变差。针对此问题,结合海上典型注聚油田地质油藏特征,利用数值模拟软件开展水聚干扰机理及影响因素研究,并在此基础上制定相应的调整策略。矿场试验表明,通过针对性优化注水井转注聚顺序及水聚注入强度,有效控制了分批次转注聚期间出现的水聚干扰,油井受益率达到86%,实现净增油482.0×10^4 m^3,提高采出程度5.1%。聚驱降水增油效果稳定,达到改善聚驱开发效果的目的。     

西南油气田含锂气田水资源调查分析

截至2020年底,国内锂资源供应对外依存度高达70%。据统计,中国石油西南油气田公司(以下简称西南油气田)各气田在开发过程中普遍产水,目前西南油气田拥有生产井1 900余口,其中超80%的生产井产水,2020年常规气气田累计产水超120×10⁸ m³。据研究报道,气田水与油气等烃类物质共同经历了漫长的油气成藏阶段,通常含有更多的微量元素,甚至部分锂资源含量高于盐湖卤水。通过气田水取样分析证实,西南油气田17口井气田水中锂离子质量浓度最高达131.6 mg/L,约50%取样井气田水中锂离子含量高于最低工业品位,同时还含有较为丰富的溴、钾等伴生资源。通过对重点井气田水跟踪评价证实西南油气田气田水锂、溴资源长周期稳定性较好,此外,西南油气田地层水资源丰富,3处重点区块地层水储量达13.3×10⁸ m³,初步估算了3处区块锂资源(以Li₂CO₃计)总价值超3 100亿元,具有较大的开发利用价值。     

Coalescence behavior of two water drops in viscous oil under an AC electric field

Electric coalescence in alternating current (AC) electric field is one of the important electrical dehydrate technologies. In this study, the coalescence behavior of two water drops in an AC electric field was studied experimentally using a high-speed camera. There is a critical electric field strength above which the two drops would not coalescence. Such coalescence behavior was supposed to be depended on the electric field strength and the frequency. Lower electric field strength, lower frequency and smaller size would facilitate the coalescence of drops. The understanding of the electric coalescence could be helpful to advance the design of the electrocoalescencers.     

塔顶注水除盐系统在渣油加氢的应用

大连石化300×104 t/a渣油装置由于进料油品中的氮、氯等多种杂质的存在,塔顶低温部位易生成氯化铵盐沉积,导致汽提塔顶馏出物管线持续腐蚀.目前装置汽提塔顶增设注水除盐系统,降低顶循环油中的氨氮及氯离子含量,缓解设备内氯化铵结盐堵塞、垢下腐蚀,汽提塔顶系统腐蚀问题得以解决.     

苏里格气田气井产水分析及新型泡排剂试验

分析了苏里格气田气井的产水类型,主要有地层水、淡化地层水、凝析水、凝析油及陈发型出水;分析了气井的井底积液特征,通过压力峰值、油套压变化、产气量变化曲线等特征可以判断气井井底积液情况。介绍了三种产水气井排查方法:生产动态分析法、关井恢复压力排查法、井筒压力梯度测试法,这三种方法是苏里格气田产水气井排查常用且有效的方法。介绍了泡沫排水采气的泡排剂优选方法及优选原则,结合试验区所产地层水的水质分析情况,优选了ERD-05起泡剂和ERD-06泡排棒这两种泡排剂;优化了泡排剂的加注制度,进行了泡沫排水采气现场试验,试验井排水、增产效果明显。