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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=689219
• 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馏分，在温度、压力或组成变化时会沉淀，有时会形成沉积物。油田设施中的沥青质沉积导致生产损失和高处理成本。需要降水和沉积过程的数据和模型，以避免或减少沉积。这项拟议的研究计划针对现有数据和模型中的两个空白，这些数据和模型与更深的储层有关，例如纽芬兰近海发现的储层，以及二氧化碳淹没的储层，其中一些在加拿大西部发现。间隙1 -溶解气体引起的沉淀：减压常规油中的沥青质沉淀强烈依赖于溶解气体含量。然而，不同的溶解气体，特别是甲烷和二氧化碳的作用还没有得到系统的研究。建议在一定温度和压力范围内测量与甲烷、二氧化碳（以及庚烷，如果需要强制沉淀的话）混合的死油的沥青质沉淀。这些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。交付成果是一个经过数据验证的相行为模型，用于所有常规石油应用中的沥青质沉淀。*差距2 -高温下开放流中的沉积：大多数沥青质沉积研究是在低温下进行的，而在海上生产中遇到的较高温度（高达130 ℃）下的沉积尚未进行严格研究。沥青质通常被认为沉淀为絮凝并可能存款的玻璃状颗粒。然而，颗粒实际上是富含沥青质的相，其在较高温度下变成液体。因此，沉积过程将在更高的温度下改变。建议设计和调试一台仪器，以研究深部储层温度和压力下的沥青质沉积。将提出沉积机制，并根据该设备中收集的数据进行测试，结果将纳入沉积模型。**建议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。该模型将用于任何深或气驱油藏的运营商。建议的沉积研究可用于评估新的离岸海岸或气驱开发是否以及在何处可能遇到沉积问题。这是保证和缓解流动的关键第一步。这项研究还将支持两个博士学位。学生谁将获得背景和培训，适合在石油工业和学术界的研究工程师的职业生涯。