Asphaltene Precipitation and Deposition from Conventional Crude Oils

常规原油中的沥青质沉淀和沉积

• 批准号: RGPIN-2018-03699
• 负责人: Yarranton, Harvey
• 金额: $ 3.35万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712515
• 关键词: Asphaltene; Precipitation; Deposition; Conventional; Crude

Asphaltenes are the heaviest fraction of crude oils and can precipitate and sometimes form deposits upon a change in temperature, pressure, or composition. Asphaltene deposition in oilfield facilities leads to production losses and high treatment costs. Data and models for the precipitation and deposition process are required to avoid or mitigate deposition. This proposed research program targets two gaps in the available data and models that are of relevance for deeper reservoirs, such as those found offshore Newfoundland, and for carbon dioxide flooded reservoirs, some of which are found in Western Canada. Gap 1 - Precipitation Caused by Dissolved Gases: Asphaltene precipitation from depressurized conventional oils is strongly dependent on the dissolved gas content. However, the roles of the different dissolved gases, particularly methane and carbon dioxide, have not been systematically investigated. It is proposed to measure asphaltene precipitation for dead oils mixed with methane, carbon dioxide (and heptane if required to force precipitation) over a range of temperature and pressures. The data will be used to determine solubility parameters for the dissolved gases to be used as inputs for a phase behavior model. Existing phase behavior models will be adapted as required to represent the data. The deliverable is a data validated phase behavior model for asphaltene precipitation in all conventional oil applications. Gap 2 - Deposition in Open Flow at Elevated Temperature: Most asphaltene deposition studies have been performed at low temperature and deposition at the higher temperatures encountered in off-shore production (up to 130C) has not been rigorously investigated. Asphaltenes are commonly considered to precipitate as glassy particles that flocculate and potentially deposit. However, the particles are in fact an asphaltene-rich phase which becomes a liquid at higher temperatures. Hence, the deposition process will change at higher temperatures. It is proposed to design and commission an apparatus to investigate asphaltene deposition at deep reservoir temperatures and pressures. Deposition mechanisms will be proposed and tested against the data collected in this apparatus and the results will be incorporated into a deposition model. The proposed precipitation models will allow operators to avoid or plan for asphaltene precipitation to sustain production and potentially avoid or reduce treatment costs. The models will be of use to any operator of a deep or gas flooded reservoir. The proposed deposition research can be used to assess if and where a new off shore or gas flood development is likely to encounter deposition problems. This is the crucial first step in flow assurance and mitigation. The proposed research will also support two Ph.D. students who will receive background and training suitable for careers as research engineers in the oil industry and academia.

沥青质是原油中最重的部分，可以沉淀，有时在温度、压力或成分变化时形成沉积物。油田设施中的沥青质沉积会导致生产损失和高昂的处理成本。需要降水和沉积过程的数据和模型来避免或减轻沉积。这项拟议的研究计划针对的是现有数据和模型中的两个空白，这些空白与更深的水库（例如在纽芬兰近海发现的水库）和二氧化碳淹没的水库（其中一些在加拿大西部发现）相关。 差距 1 - 由溶解气体引起的沉淀：减压常规油中的沥青质沉淀很大程度上取决于溶解气体含量。然而，不同溶解气体，特别是甲烷和二氧化碳的作用尚未得到系统研究。建议在一定温度和压力范围内测量与甲烷、二氧化碳（和庚烷，如果需要强制沉淀）混合的死油的沥青质沉淀。该数据将用于确定溶解气体的溶解度参数，以用作相行为模型的输入。现有的相行为模型将根据需要进行调整以表示数据。可交付成果是所有传统石油应用中沥青质沉淀的数据验证相行为模型。 差距 2 - 高温下明流沉积：大多数沥青质沉积研究都是在低温下进行的，而海上生产中遇到的较高温度（高达 130°C）下的沉积尚未经过严格研究。沥青质通常被认为以玻璃状颗粒形式沉淀，絮凝并可能沉积。然而，这些颗粒实际上是富含沥青质的相，在较高温度下会变成液体。因此，沉积过程将在较高温度下发生变化。建议设计并调试一种装置来研究深层油藏温度和压力下的沥青质沉积。将根据该设备中收集的数据提出和测试沉积机制，并将结果纳入沉积模型中。 所提出的沉淀模型将允许运营商避免或计划沥青质沉淀以维持生产，并可能避免或降低处理成本。这些模型将对任何深层或气驱油藏的操作者有用。拟议的沉积研究可用于评估新的海上或气驱开发是否以及在何处可能遇到沉积问题。这是流量保证和缓解的关键的第一步。拟议的研究还将支持两名博士生。学生将接受适合石油工业和学术界研究工程师职业的背景和培训。