Experimental investigations of fracturing fluid flowback and retention under forced imbibition in fossil hydrogen energy development of tight oil based on nuclear magnetic resonance
| Autor: | Yang Shi, Yujiao Han, Yun Jiang, XingHang Zeng, Mingxian Wang, Guoqing Xu |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Hydrogen Energy Engineering and Power Technology chemistry.chemical_element 02 engineering and technology 010402 general chemistry 01 natural sciences law.invention Pore water pressure Nuclear magnetic resonance law medicine Filtration Renewable Energy Sustainability and the Environment Tight oil 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Water retention Fuel Technology chemistry Hydraulic fluid Imbibition medicine.symptom 0210 nano-technology Displacement (fluid) |
| Zdroj: | International Journal of Hydrogen Energy. 45:13256-13271 |
| ISSN: | 0360-3199 |
| DOI: | 10.1016/j.ijhydene.2020.03.054 |
| Popis: | Experimental works have proved that imbibition under forced pressure (FP, the difference between hydraulic fluid pressure and original pore pressure) has a positive effect on fossil hydrogen energy development in tight oil reservoir. However, the knowledge of the influence of imbibition under forced pressure (forced imbibition, FI) on fracturing fluid flowback and water retention is still limited. In this paper, experiments were designed and conducted to reveal the mechanism of fracturing fluid flowback and water retention under imbibition effect in tight sandstones. As a comparison, unconsolidated sandstones were also investigated in this study. Core samples were divided into two categories: the imbibition ones (treated by imbibition) and the filtration ones (treated by displacement), in accordance with the real oil-water distribution after well shut-in. An imbibition core and a filtration core were stitched together to conduct a flowback experiment. During the experiment, fluid distribution in different pore sizes was monitored continuously by using a low-field nuclear magnetic resonance device. Results show that the flowback recovery in tight sandstones is much lower than that in unconsolidated sandstones due to the difference of pore structure. Meanwhile, forced imbibition leads to higher oil recovery than spontaneous imbibition (SI) in tight sandstones since forced pressure enhances water imbibition. The water imbibed into small-macro and macro pores contributes the major flowback recovery, but the imbibed water in micro pores is rather difficult to displace and finally retains in these pores during the flowback process. Overall, forced imbibition not only enhances oil recovery but also increases water retention, explaining the mechanism of well productivity increase by using the shut-in method in the field. This study can help to clarify the influence of forced imbibition on fracturing fluid flowback and enhancement of fossil hydrogen development, and further provide guidance for flowback designs. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect