超声在超重油降粘和高凝油降凝中作用机理的研究

Due to the shortage of the fossil fuel and with the increasing demand for it, the unconventional oil and gas such as ultra-heavy crude oil (UHCO) whose density is less than 10 API and the high pour point crude oil (HPPCO) whose pour point is above 40℃ are getting more and more attention in the world. But their properties of heavier density, higher viscosity, higher pour point, higher wax content and worse fluidity make it very difficult to produce and transport them. The present methods of reducing viscosity and pour point, such as heating, diluting lighter crude oil and adding viscosity reducer and pour point depressant may damage the formation, have the difficulties in desalting and dewatering and are not safe enough. To solve the problems which are still very difficult technically in the world, the safer, more economical and effective methods which can be used to reduce viscosity of UHCO and pour point of HPPCO must be developed. And the mechanisms of effects of high intensity ultrasonic wave on the viscosity reduction of UHCO and pour point reduction of HPPCO will be emphatically investigated in this proposal. This research will focus on the mechanisms of the interactions between ultrasonic wave and UHCO, HPPCO, viscosity reducer and pour point depressant (PPD). The UHCO and HPPCO samples will be processed and undergo the acoustic effects such as acoustic cavitation, jet, shaking and so on, which are arranged elaborately. The effects of high intensity ultrasonic wave on the saturate, aromatic, resin and asphaltene fractions (SARA) of the samples and their molecular structure , the solubility of resin and asphaltene, the component and structure of paraffin, the molecular functional groups of emulsions of viscosity reducer and PPD will be investigated and analyzed in detail by means of viscosity measurement, differential scanning calorimetry, infrared spectroscopy, gas chromatography, scanning electron microscopy et al. The results obtained in this proposal can provide fundamental basis for the development of new ultrasonic technologies of reducing the viscosity of UHCO and pour point of HPPCO, which is helpful for improving and keeping good fluidity of UHCO and HPPCO during their extraction and pipe transportation.

随着能源的短缺，重度小于10的超重油和凝点高于40℃的高凝油等非常规资源越来越受到人们的重视。但其粘度大、凝点高等特点使得它们的开采运输难度极大。现有的加热、掺轻质油和添加化学药剂的降粘降凝方法存在对地层造成破坏、后续处理难度大和有安全性隐患等不足。针对这一难题，本项目拟研究高强超声和声空化等声学效应与超重油/高凝油以及添加的降粘剂降凝剂等化学药剂的相互作用机理。通过控制超声和声空化等对超重油/高凝油的处理，借助粘度测量、红外光谱、气相色谱，电镜扫描等测试方法，分析高强超声对超重油/高凝油中族组分组成的改变、对结构不同的族组分分子结构、对胶质和沥青质等成分溶解度、对蜡质成分和分布结构、对降粘剂和降凝剂乳化液分子官能团等的影响，得出超声在超重油降粘和高凝油降凝中的作用机理并进行验证。研究结果可为超重油高凝油降粘降凝中超声技术的应用提供基础，为研发改善超重油/高凝油流动性的超声方法提供依据。

随着能源的短缺，超重油和高凝油等非常规资源越来越受到人们的重视。针对其粘度大、凝点高、难以开采运输的难题，项目以委内瑞拉、新疆地区超重油和苏丹、海南福山高凝油为主要研究对象，设计了超声降粘和降凝实验方案，搭建了测试评价平台，研制了可在线处理重油的功率超声换能器，研发了井口超声辅助降粘试验设备，实现了超声辅助超重油降粘的初步工业规模应用。.首先，用超声方法解决了超重油水包油降粘体系因滑脱剪切应力造成降粘体系动态不稳定性难题。通过设计实验方案，优化核心关键参数，突破超声辅助重油降粘管输的技术瓶颈。成功实现保持降粘体系动态稳定性45天以上，经超声处理的体系粘度下降40%以上，并减少30%剂量。.其次，研究了超声对高凝油凝点、高温蒸馏组分和高碳数分子链的影响，成功实现了降低其凝点2℃以上，分析了超声的作用机理。采用蜡结构相近的石蜡样品，设计实验，对超声在高凝油降凝中的作用机理进行了验证。.基于理论分析和数值仿真，设计研制可在线连续工作的超声降粘换能器。解决换能器指向性、辐射面结构、耐高温等难题。对换能器在液体中的侵入深度对声场指向性影响，容器横向尺寸对声场分布影响参数进行了分析优化。.搭建了实验测试评价平台。在实验室研究的基础上，按照油田井口集输需求，结合油井工况和采油工艺，自主设计、研发了超声油井井口降粘样机设备。确定了设备工作参数。重点解决了超声处理系统、降粘剂配给系统和井口采输系统之间的匹配问题。目前已在新疆油田完成了两口油井一年以上的现场试验，设备降粘效果很显著，成功实现超重油的管线输送，后续的示范推广正在开展。.研究了高频声空化场的分布及声化学反应效率，设计研制了适合工业应用的双高频超声反应器并进行了实验。建立了一套超声和流体动力联合作用的声-流耦合空化系统，对耦合空化产生协同效应的物理机理进行了分析，为声能在工业大规模应用进行了探索和尝试。.最后给出了下一步工作和攻关的建议。