带压作业现状与发展浅析

带压作业是在保持井筒内一定压力,不压井、不放压的情况下进行起下管柱的一种先进井下作业技术。相较于传统井下作业,带压作业的优势在于它能够最大限度的实现对油气层和环境的保护,有利于油气水井修复后的稳产和提高注水效率。带压作业技术在国外已经广泛应用,开发出了系列带压作业装置,并形成了较为完善的配套技术体系。目前国内也开展了相应的研究,逐步推广应用,并取得一定成果,但仍存在着较多问题。文章通过借鉴国外的先进经验,找出国内技术现存问题,并提出应当把管柱内堵塞技术、短冲程带压作业装置的完善及长冲程带压作业装置的引进和研发作为切入点,希望对国内带压作业技术的发展有所促进。     

清洁生产在江苏油田采油工艺中的应用

近年来,江苏油田加大采油清洁生产系列工艺技术的研究力度,自行研发了插管卡堵水采油工艺、侧钻井卡堵水工艺、带压作业技术、中频感应加热单管集输工艺、太阳能辅助电加热技术等一系列新型节能、降耗、减污、增效的采油清洁生产工艺技术,并在油田开发中得到了广泛的应用,取得了明显的经济和社会效益。     

带压作业技术的应用前景

油气田开采中后期，油气井作业频繁，修井工作量大。为提高采收率，延长开采周期，不伤害地层，且能保持油气井产能增产等，可使用带压作业技术。     

大庆油田井下环保作业模式的建立与完善

大庆油田从污染源头抓起,针对整个井下作业流程中存在的环保问题,建立了污油污水不落地的清洁环保作业模式,通过原井管柱污染防治、起下过程废液收集、管柱内防喷、高压油水井带压作业等新型技术的研发和应用,有效地抑制了井下作业过程中环境污染问题的发生。文章对新型清洁环保作业模式进行了阐述,介绍了所研发新型环保技术的工艺特点及应用效果;并基于油田经济与生态环境的平衡和谐发展,对未来环保作业技术研究方向提出了意见和建议。     

井下作业环境污染防治技术研究及应用

通过对井下作业过程中产生的各种污染物及其来源进行分析,有针对性地制订出一系列配套的环境治理工艺技术及控制措施,并对带压作业、循环冲砂车等新技术、新工艺的设备构造、工作原理进行介绍,对其应用效果进行分析。通过采用这一系列控制措施,环境污染防治效果显著;通过带压作业最大限度地保持了油气层原始地层状态,避免了发生溢流或井喷的风险;循环冲砂车的使用年节约用水22500 m~3,回收原油约1000 t。     

大庆油田带压作业安全环保风险分析与对策

通过对大庆油田近15年油水井带压作业施工进行分析，从井筒管柱、地面设备设施、现场管理3个方面找出存在的安全环保风险，评价这些风险产生的机理和危害，完善现场管理制度、研发或配备遏制安全环境事故发生的专业设备装置、优化完井及配合施工工艺等防范措施，有效减少带压作业可能出现的安全环保问题。     

油气管线带压不停输封堵技术在长庆油田的应用

长庆油田通过对管道不停输带压封堵施工技术的探索,在改扩建工程施工中取得了良好的效果。实践证明,与常规施工方法相比可有效缩短维护抢修作业工期20%～30%。它在油气田风险管理、事故预防、环境污染治理方面是积极安全有效的。     

长庆油田井下作业关键环保技术及应用

井下作业过程中会产生大量返排液和含油污泥,易造成井场环境污染。文章梳理了长庆油田井下作业存在的环保问题,提出了采油管柱密闭清洗技术、油管连续循环密闭洗井技术、分段压裂上提油管防喷技术、液压式防喷泄油器和带压作业5项井下作业关键环保技术。自2017年以来,现场应用井下作业环保技术150余井次,单井平均减少废液28.2 m~3,减少含油污泥0.2 t,实现作业过程零污染,有效地抑制了环境污染。     

会议信息

正数控机床可靠性快速试验技术研讨会在京召开2014年1月21日,"数控机床可靠性快速试验技术"研讨会在北京召开。研讨会上,国家机床监督检验中心赵钦志主任作了"数控机床可靠性快速试验技术"研究报告,报告从可靠性分析方法、新产品可靠性预测的技术特点、基于失效征兆映射的可靠性快速试验原理、征兆映射模型的隐函数建模及分析技术、数控机床失效征兆确定的原理和方法、可靠性快速试验工况系数的确定、可靠性快速试验、可靠性快速试验情况及分析等八个方面详细介绍了课题的研究成果。     

水驱气藏污水回注能力评价与指标预测

为避免水驱气藏产出污水排海而引起海洋污染问题,开展了水驱气藏回注能力评价技术研究:以物质平衡为基础,确定不同气水界面和饱和度分布下的可注入总量;建立井筒管流模型,确定不同注入量下的摩擦阻力、井底流压,预测注入泵压的变化趋势;提出了回注指标优化图版,可快速优化回注井的瞬时注入量。研究成果已初步应用于靶区首次污水回注试验,单井日注水规模达100~250 m³,回注总量为1.06×10⁴ m³,有效避免了地区的环境污染问题。     

驱排剂解堵工艺的研究与应用

吐哈温米油田属于低孔、低渗、低产能油藏,原油含蜡量、沥青质较高,油井的近井地带结垢严重。文章介绍了驱排剂的解堵作用原理、酸化工作液配方、驱排剂解堵工艺技术和现场应用效果。研究结果表明,驱排剂解堵工艺技术对解除油井的堵塞具有良好的效果,对提高油井的产液能力有重要作用,同时又是低渗透油田增产的一种新工艺。从2004年7月份开始,温米油田利用驱排剂解堵后油井平均单井日增油量3.0t,日增液量21.0t,动液面平均上升400.00m,平均单井有效生产期为90天以上。     

油气处理终端环境风险评估与防范对策

环境风险评价是油气处理终端环境影响评价工作的重要组成部分。根据HJ 169—2018《建设项目环境风险评价技术导则》的要求,文章对油气处理终端潜在的环境风险进行评估,进行了环境风险识别、风险事故情形分析,确定了油气终端环境风险管理的薄弱环节,选择原油储罐、液化石油气储罐全破裂和陆地混输管线全管径泄漏为最大可信事故。并针对性地提出了环境风险防范措施,提高工程设计安全系数,实现本质环保;构建地表水环境风险防控体系,完善事故水封堵系统;做好分区防渗措施,实现污染物源头控制等;为油气终端环境风险评估及风险防控提供了理论和技术支持。     

农村家园污水人工湿地处理示范工程研究

近年来国内农村家园和乡镇建设了不少人工湿地，但常出现渗漏、堵塞、短流、恶臭、去除效率低、管理粗放、资源未综合利用等问题，能长期正常运行的少，缺乏可靠运行的范例。为此，我们开展了农村家因污水、雨水人工湿地处理及综合利用研究，取得了一定的进展并在四川省成都市安德镇安龙村建设了示范工程。     

Certification framework based on effective trapping for geologic carbon sequestration

We have developed a certification framework (CF) for certifying the safety and effectiveness of geologic carbon sequestration (GCS) sites. Safety and effectiveness are achieved if CO₂ and displaced brine have no significant impact on humans, other living things, resources, or the environment. In the CF, we relate effective trapping to CO₂ leakage risk which takes into account both the impact and probability of leakage. We achieve simplicity in the CF by using (1) wells and faults as the potential leakage pathways, (2) compartments to represent environmental resources that may be impacted by leakage, (3) CO₂ fluxes and concentrations in the compartments as proxies for impact to vulnerable entities, (4) broad ranges of storage formation properties to generate a catalog of simulated plume movements, and (5) probabilities of intersection of the CO₂ plume with the conduits and compartments. We demonstrate the approach on a hypothetical GCS site in a Texas Gulf Coast saline formation. Through its generality and flexibility, the CF can contribute to the assessment of risk of CO₂ and brine leakage as part of the certification process for licensing and permitting of GCS sites around the world regardless of the specific regulations in place in any given country.     

LEACHATE LEAKAGE FROM LANDFILLS WITH MODERN LINER SYSTEMS1

ABSTRACT: Recent technological advances have led to a new generation of landfill liner systems that are highly effective at intercepting and removing leachate. Many of the modern liner systems are so effective that they allow very little or no leakage. Indeed, the amount of leakage through those liners is so minimal that, although it can be theoretically predicted, it cannot be measured with the available monitoring well technology. In addition to being highly effective, some modern liner systems are constructed with two liner layers separated by a drainage medium that detects and removes any leakage through the top liner. These significant improvements in liner system technology have led to the questioning of the necessity for the currently required high number of monitoring wells. Reduction of the number of the monitoring wells and/or of the frequency of sampling would result in substantial cost savings. The present study reports the results of a research project conducted at eleven municipal landfills with modern liner technology throughout the State of Florida. Through actual field data and computer modeling, it was found that the liner systems standards applied in the State of Florida are very effective at preventing any groundwater contamination. Thus, the present monitoring well regulations are too conservative.     

自愿减排项目碳泄漏：内涵、类别及应对

自愿减排项目是碳排放交易市场抵消机制的运行载体,灵活的自愿减排抵消机制是碳排放交易市场的补充,对应对全球气候变化问题具有重要意义。碳泄漏,作为严重影响抵消项目减排效率的热点问题值得关注。目前,中国已形成较大规模的自愿减排市场,截至2018年底,国家发展改革委共签发了约7200万tCO_2当量减排量,我国在建立健全自愿减排抵消市场机制的过程中,需要把握项目碳泄漏的负外部性这一实质,厘清其运行机理并积极应对。本文旨在系统阐述该问题,并为进一步实现抵消项目减排潜力提供思路和方向:从自愿减排项目碳泄漏的内涵与定义出发,首先对项目碳泄漏的分类进行梳理,并依据产生途径的不同重点分析了活动转移排放、生命周期、市场路径、生态以及技术泄漏的作用机制、影响因素及其相应的研究方法;其次从具体项目应用、系统项目应用和宏观应用三个层面讨论了应对自愿减排项目碳泄漏问题的管理对策;最后结合我国自愿减排抵消市场的实际情况,建议未来抵消项目碳泄漏的应对和管理应在分门别类对其概念进行精准定义的基础上将解决措施的成本效益考虑在内,此外,在评估泄漏量时需要同时测算不同类型的碳泄漏,探究其协同效应以免高估其泄漏程度。     

Drain-blocking techniques on blanket peat: A framework for best practice

In recent years there has been a dramatic increase in artificial drain-blocking in world peatlands. The UK blanket peatlands have been severely drained over the past few decades but now drains are being blocked in an attempt to improve peatland environments. The drain-blocking has been a disparate process with limited knowledge transfer between organisations and within organisations operating in different geographic areas. Consequently, there has been no compilation of techniques used and their effectiveness. During this study thirty-two drain-blocked sites were surveyed and all the key stakeholders interviewed. Drain-blocking using peat turf was preferred by practitioners and was also the most cost-effective method. Peat turves were successful except on steep slopes, in areas of severe erosion, in very wet or very dry locations, or if the mineral substrate was exposed. A drain-blocking best practice guide is offered by this paper, providing information on the most suitable methods for blocking peatland drains under different circumstances. Additional considerations are provided for practitioners to ensure peatland drain-blocking is as successful as possible.     

The Influence of Tip Leakage Flow on Flowfields in a Highly Loaded Transonic Rotor with Forward Sweep

A three-dimensional numerical simulation on a highly loaded transonic rotor with zero, 0.2 mm, 0.3 mm, and 0.5 mm tip gap, respectively, is performed in this article. The flowfields above 60% span of transonic rotors are affected by leakage flow, but the stall margin of rotor has obviously improved with small tip gap. Typical leakage vortex structures with double cores are generated by the interaction of incoming flow, leakage flow, and second flow in flowfields, and then the two vortex cores merge into a stronger one in front of shock. The shape of passage shock changes seriously by strong leakage vortex after interaction and a large low-velocity region generates behind shock in tip region. The blockage, produced by leakage flow and boundary layer separation, induces detached shock wave near leading edge of rotors and triggers the rotating stall of compressor. However, with tip gap increasing, the blockage produced by leakage flow tends to be dominant in occurrence of rotating stall. Once the tip clearance adds to 0.5 mm, vortex breakdown in tip region of rotor appears and the flow deteriorates drastically, which aggravates the onset of stall in rotor.     

Comparison of data-based methods for monitoring of air leakages into oxyfuel power plants

Air leakages compromise the CO₂ capture rate and auxiliary power consumption of oxyfuel power plants. Constructive measures can significantly improve the leakage rate in newly built plants. However, the mitigation of increasing leakage rates during the plant lifetime is crucial for high plant efficiency. In this paper, we apply three statistical methods on experimental process data gathered in an air leakage test in Vattenfall's Oxyfuel Pilot Plant in Schwarze Pumpe, Germany. The performance of the methods in identifying increasing leakage rates and localizing the leakage source is investigated. It was found that all three methods can identify and localize even small increases of the leakage rate. A combination of all three methods allows taking advantage of the individual features of each method. Additional installation of CO₂, O₂, H₂O, and SO₂ measurements in the oxidizer can considerably enhance localization performance. Finally, it is shown that the results can be transferred to commercial-scale oxyfuel pilot plants by generating training data with thermodynamic plant models.     

石油石化企业泄漏检测技术现状及前景

石油石化站场设备繁多,挥发性介质泄漏易造成安全事故。目前站场点式、线式等固定式检测设备存在泄漏检测反应滞后、泄漏点定位困难等缺点,便携式检测设备人工巡检工作量大。文章对可调谐二极管激光吸收光谱技术、红外热成像技术、红外多光谱技术和红外高光谱技术进行了分析,提出红外成像检测技术在泄漏检测方面优势明显,具有视频成像、反应迅速、定位准确、连续监控等优点,有望在石油石化行业普及。