Release of expansion agents for well cementing
US10526523B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 2016 |
| Grant date | Jan 7, 2020 |
| Priority date | — |
| Expiry date | Feb 11, 2036 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/14
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Pre-stressed cementing methods involve preparing a cement slurry containing water, inorganic cement, and capsules of an expanding agent. The slurry is placed in an annular region in the well and hardened. Expansion of the set cement is delayed. Water infiltration activates the expanding agent to rupture the capsules and release the expanding agent. The expanding agent reacts to expand the set cement to a state of compression within the annular region. The state of compression can be maintained during changes in casing dimensions from temperature or pressure, mechanical disturbance, or mud contamination. The state of compression in the annular region may be monitored by acoustic impedance measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.