2001 Technology for a Sustainable Environment: An Environmentally Sustainable Approach to Crude Oil Production and Processing: Compressed Gas Demulsification

美国北卡罗来纳州基尔帕特里克原油生产、运输和加工过程中的乳化液管理是石油工业面临的最持久的挑战之一。每年，石油生产过程中产生数千万吨乳化液，随着重油产量的增加，这一数字可能每年都会上升。这些乳液中有很大一部分是由吸附的沥青质弹性膜稳定的。通常用化学破乳剂处理这些乳状液，通常是含有相当比例的环氧乙烷(EO)和环氧丙烷(PO)的非离子聚合物。其他使用程度较低的方法包括热加压和快速降压、静电液滴破碎和聚合以及乳状液的超声波处理。最有效的化学破乳剂有烷氧基苯酚树脂、苯酚-甲醛缩水甘油醚和其他以环氧乙烷、环氧丙烷、苯酚和甲醛为基础的聚合物。有相当大的担忧，因为许多这些破乳剂化学物质持续存在于环境中，是不可生物降解的，可能会对人类健康产生不利影响，包括被怀疑是内分泌干扰物。此外，破乳剂在特别笨重和麻烦的领域的相关成本可能会很高。这个项目描述了一种使用压缩气体破乳水-石油乳状液的新方法；具体的例子是使用压缩二氧化碳(CO2)。该项目描述了这种方法的进一步发展和混合压缩气体的可能使用，包括甲烷(CH4)、乙烷(C2H6)、丙烷(C3H8)和二氧化碳。该方法是基于溶解气体溶解时石油对沥青质的溶剂性质的改变。众所周知，石油流体中大量丙烷的溶解可以沉淀沥青质，这一过程被称为丙烷脱沥青。二氧化碳也是非常有效的，其沉淀量足以使极其稳定的石油乳状液破乳。如果这种方法对通常与石油接触并与石油共生的压缩气体--例如CH4、C2H6、C3H8和CO2--是可行的，那么就有可能从源头上对产生的乳状液进行破乳，并可能对原油进行初步的单元操作，如井下脱沥青。这种技术的影响，如果成功地简化为经济实践，将很难高估。根据经修订的预算削减导致的范围有所缩小，混合气体的破乳将仅使用甲烷(CH4)和二氧化碳。

AbstractCTS-0124760Kilpatrick, PNorth Carolina State UThe management of emulsions during the production, transportation, and processing of crude petroleum fluids is one of the most persistent challenges which faces the petroleum industry. Annually, tens of millions of tons of emulsions are produced during production of petroleum and this figure is likely to rise annually with the increased production of heavy oils. A substantial percentage of these emulsions are stabilized by elastic films of adsorbed asphaltenes. It is common to treat these emulsions with chemical demulsifiers, typically nonionic polymers containing substantial proportions of ethylene oxide (EO) and propylene oxide (PO). Other methods employed to a lesser extent include thermal pressurization and rapid depressurization, electrostatic droplet shattering and coalescence, and ultrasonication of emulsions. Among the most effective chemical demulsifiers are oxyalkylated phenol resins, phenol-formaldehyde glycidyl ethers, and other polymers based on EO, PO, phenol, and formaldehyde. There is considerable concern in that many of these demulsifier chemicals persist in the environment, are nonbiodegradable, and may have adverse human health effects, including being suspected endocrine disruptors. Moreover, the costs associated with demulsifiers in particularly heavy and troublesome fields can be substantial. This project describes a novel method for demulsifying water-petroleum emulsions using compressed gases; the specific example which has been reduced to practice is the use of compressed carbon dioxide (CO2). The project describes the further development of this method and the possible use of mixed compressed gases, including methane (CH4), ethane (C2H6), propane (C3H8), and CO2. The method is based on the alteration of the solvent properties of petroleum for asphaltenes upon dissolution of dissolved gas. It is well known that dissolution of appreciable amounts of propane in petroleum fluids can precipitate asphaltenes, a process known as propane de-asphalting. CO2 is also highly effective and the precipitation is of sufficient magnitude to demulsify extremely stable petroleum emulsions. Should the method be plausible with compressed gases commonly found in contact and coproduced with petroleum - e.g. CH4, C2H6, C3H8, and CO2 - the possibility exists for demulsifying produced emulsions at the source and, perhaps, perform preliminary unit operations on the crude, such as downhole deasphalting. The impact of such a technology, if successfully reduced to economical practice, would be difficult to overestimate. Based on the somewhat reduced scope due to the revised budget reductions, the mixed gas demulsifications will be performed with methane (CH4) and CO2 only.