Carbonate reservoir filtration-loss self-reducing acid
US11174425B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 2020 |
| Grant date | Nov 16, 2021 |
| Priority date | — |
| Expiry date | Jun 24, 2040 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/26
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to a carbonate reservoir filtration-loss self-reducing acid fracturing method. The carbonate reservoir filtration-loss self-reducing acid fracturing method comprises the steps: (1) calculating a fracture pressure and a fracture extension pressure of a reconstructed reservoir; (2) injecting an agent A into a stratum under a pressure higher than the stratum fracture pressure, so that fractures are generated on the stratum; (3) injecting an agent B into the stratum under a pressure higher than the stratum fracture pressure, such that the agent B extends the fractures and communicates with a natural fracture net; (4) pumping an acid liquor system agent C with a high etching power into the stratum under a pressure higher than the extension pressure but lower than the fracture pressure to improve the conductivity of the fractures; (5) injecting a displacing liquid agent D under a pressure lower than the stratum fracture pressure to jack acid liquor in a well casing into the stratum; and (6) shutting down a well and performing flow-back. The agent A is a gel acid or VES acid, the agent B is a filtration-loss self-reducing gel acid or filtration-loss self-redu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.