Quantification of the concentration dependent diffusivity and dispersivity of light hydrocarbons in heavy oil

重油中轻质烃的浓度依赖性扩散率和分散率的量化

• 批准号: 402561-2011
• 负责人: James, Lesley
• 金额: $ 1.75万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=573319
• 关键词: Quantification; concentration; dependent; diffusivity; dispersivity

The oil sands in western Canada account for 180 of the 185 billion barrels of recoverable oil but contain heavy oil and bitumen whose viscosity ranges from 1,000 to over one million centipoises (water is 1 cP). The recovery of the in-situ heavy oil relies on our ability to reduce the oil's viscosity and mobilize it in the pore space of tightly packed sand grains or consolidated carbonate rocks. Commercially, energy and water intensive thermal methods are used where steam is injected into one well, viscosity is reduced by heat transfer, the oil is mobilized to the production well and brought to the surface. A less energy intensive and more sustainable method uses light hydrocarbon solvents instead of steam to reduce the bitumen's viscosity via mass transfer. The goal of the "Quantification of the Concentration Dependent Diffusivity and Dispersivity of Light Hydrocarbons in Heavy Oil" is to 1) further examine the concentration dependent diffusivity of light hydrocarbons in heavy oil and bitumen, and 2) quantify the mass transfer at the pore scale. The first goal is to expand the previously developed mathematical model. (James et al. 2010) The new model will incorporate thermodynamics for non-ideal solutions. Using the new model we will perform a parametric study to develop an empirical correlation for the diffusivity of light hydrocarbons in heavy oil/bitumen. The novelty of this work would be the development of a new empirical correlation to replace historic correlations. The second goal is to quantify the mass transfer at the pore scale by developing a methodology to measure the dispersivity of solvent in heavy oil, then using the dispersivity and the diffusivity; we will calculate the dispersion coefficient for laboratory conditions and compare it to otherwise found (back calculated, tuned parameter or correlation) dispersion coefficients. Separate knowledge of the dispersion and diffusion will provide insight into the pore-scale physics and enable a more accurate physical description of the process in pre scale mathematical models.

加拿大西部的油砂占1850亿桶可开采石油中的180桶，但含有重油和沥青，其粘度范围从1，000到超过100万厘泊（水为1厘泊）。原位稠油的开采依赖于我们降低原油粘度并将其在紧密堆积的砂粒或固结碳酸盐岩的孔隙中流动的能力。在商业上，使用能量和水密集型热方法，其中将蒸汽注入一口井中，通过热传递降低粘度，将油移动到生产井并带到地面。 一种能耗更低、更可持续的方法是使用轻质烃溶剂代替蒸汽，通过传质降低沥青的粘度。 “重油中轻烃的浓度依赖扩散率和分散率的量化”的目标是1）进一步检查重油和沥青中轻烃的浓度依赖扩散率，和2）量化孔隙尺度下的质量传递。第一个目标是扩展先前开发的数学模型。（James et al. 2010）新模型将纳入非理想溶液的热力学。 使用新的模型，我们将进行参数化研究，开发经验的轻质烃在重油/沥青的扩散系数的相关性。这项工作的新奇将是发展一种新的经验相关性来取代历史相关性。第二个目标是通过开发一种方法来测量溶剂在重油中的分散性，然后使用分散性和扩散性来量化孔隙尺度下的传质;我们将计算实验室条件下的分散系数，并将其与其他方法（反算，调整参数或相关性）的分散系数进行比较。 分散和扩散的单独知识将提供对孔隙尺度物理的深入了解，并能够在预尺度数学模型中对过程进行更准确的物理描述。