Integrated method for nitrogen-assisted carbon dioxide fracturing and development of shale oil reservoirs
US11371328B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 2021 |
| Grant date | Jun 28, 2022 |
| Priority date | — |
| Expiry date | Dec 9, 2041 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/267
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The invention discloses an integrated method for nitrogen-assisted carbon dioxide fracturing and development of shale oil reservoirs, comprising the following steps: fracture the target shale reservoir with nitrogen-assisted carbon dioxide; after fracturing, firstly inject carbon dioxide gas into the target shale oil reservoir, and then inject nitrogen gas to push the carbon dioxide gas into the further location of the oil reservoir; shut in the well in the target shale oil reservoir; after shut-in, open the well to implement depletion production; after the first cycle of production, the slug volume of the injected gas and the shut-in time are 1.5 times of those in the previous cycle in the subsequent production, and Steps 5 to 7 are repeated for each cycle. The present invention maximizes the recovery efficiency of shale oil reservoirs; in this way, carbon dioxide gas can be used most efficiently, making the development of shale reservoir more economical and efficient; the integrated fracturing and development design enables the field operation to be streamlined and standardized, and thus different departments to cooperate each other closer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.