Fundamental Understanding of Oil Adhesion Under Reservoir Conditions (FOilCon).

点击翻译按钮获取中文摘要

Growing global demand for oil, diminishing availability of conventional sources and increased sustainability criteria mean enhanced oil recovery (EOR) operations are increasingly deployed to extend reservoir life. This is especially true for mature UKCS fields, and BP has invested £120 million to deploy low salinity water EOR (Claire Ridge Field) to realise an additional 42M barrels of oil over the field life. Despite its increasing use, the geochemical basis of low salinity EOR is still not well understood. Oil wettability is linked to its "ability" to adhere to rock surfaces, which mainly occurs by the interaction of polar oil components with different mineral/grain surfaces. Therefore, understanding how EOR works requires a direct knowledge of the mechanisms controlling these interactions. To date most studies on the topic have been of an indirect nature, where a solution is flown over a core sample and different outputs are measured. More recently, chemical force microscopy (CFM) has been deployed to directly measure the adhesion between organic functional groups (representative of oil molecules) and mineral surfaces, but these measurements have been exclusively done at room temperature and pressure, in other words, well outside the conditions encountered in real reservoirs. This proposal seeks to alleviate this situation by designing, building and deploying a next-generation hydrothermal atomic force microscope (HAFM). Atomic force microscopy (AFM) has proved to be a key technique in studying a wide variety of phenomena at the nanoscale. This is due to its extremely high vertical (below 1 Å) and lateral (5-10 nm) resolution and its ability to perform studies in solution. Therefore, the AFM can provide quantitative kinetic data at the scale of elementary reactions and also qualitative information on multitude of processes (dissolution, precipitation, etc). Chemical force microscopy is a derivative of conventional AFM, where the tip is functionalised with a specific functional group and then it's approached to a surface, allowing for the measurements of interaction forces, including adhesion. Currently, however, hydrothermal conditions are beyond the range of commercial systems and only a handful of custom systems can reach temperatures of 130 C. The main goal of this grant is to develop a next-generation hydrothermal AFM. The main characteristics of this system will be: 1) Ability to reach 180 C and 20 atm. 2) The addition of XY translation stage, opening the door to study sub-mm crystals. 3) State-of-the-art fluid delivery system and custom-made fluid cell to perform experiments at any pH range desired. Once built, the HAFM will be deployed to study mineral-oil interactions at the nanoscale by means of CFM. Investigations in oil-mineral surface interactions will be carried out with different functionalised tips, representing a variety of functional groups (as present in crude oil), and will be carried out under solutions of different salinities with the goal of understanding the low salinity effect on reducing oil-surface adhesion. The application of the proposed instrument can have wide ranging implications in the NERC's strategic research areas of Physics and Chemistry of Earth Materials, and Sediments and sedimentary processes. In addition, the new HAFM, will have a range of applications outside the NERC's remit as well as in industry.