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

在原油流体的生产、运输和加工过程中，乳剂的管理是石油工业面临的最持久的挑战之一。在石油生产过程中，每年产生数千万吨乳剂，随着重油产量的增加，这一数字可能每年都在上升。这些乳剂中有很大一部分是由吸附沥青质的弹性膜稳定的。通常用化学破乳剂处理这些乳剂，通常是含有大量环氧乙烷（EO）和环氧丙烷（PO）的非离子聚合物。在较小程度上采用的其他方法包括热加压和快速降压，静电液滴破碎和聚并，以及乳剂的超声波。其中最有效的化学破乳剂是氧烷基化苯酚树脂、酚醛缩水甘油醚和其他基于EO、PO、苯酚和甲醛的聚合物。令人相当关切的是，许多这些破乳剂化学品持续存在于环境中，是不可生物降解的，可能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，在特别重质和麻烦的油田中，使用破乳剂的成本可能相当高。本项目介绍了一种利用压缩气体破乳水-石油乳状液的新方法；具体的例子已经减少到实践是压缩二氧化碳（CO2）的使用。该项目描述了该方法的进一步发展以及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后石油对沥青质的溶剂性质的改变。众所周知，在石油流体中溶解相当数量的丙烷会析出沥青质，这一过程被称为丙烷脱沥青。CO2也是非常有效的，并且沉淀的量足以破乳非常稳定的石油乳剂。如果该方法适用于通常与石油接触并共同生产的压缩气体，例如CH4、C2H6、C3H8和CO2，那么就有可能从源头对产出的乳剂进行破乳，也许还可以对原油进行初步的单元操作，例如井下脱沥青。这种技术的影响，如果成功地用于经济实践，将很难被高估。由于修订预算的削减，范围有所缩小，因此混合气体破乳将仅使用甲烷（CH4）和二氧化碳进行。

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.