Method and composition for preserving core sample integrity using a water soluble encapsulating material
US5546798A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 1995 |
| Grant date | Aug 20, 1996 |
| Priority date | — |
| Expiry date | May 12, 2015 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B25/08
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The present invention provides a method and composition for encapsulating a core sample as it enters a core barrel with a water-based encapsulating material that preferably comprises an expandable lattice type clay. The water-base causes the expandable lattice type clay to swell, forming a plastic mass which can be pumped into a core barrel to encapsulate the core sample and maintain the chemical and mechanical integrity of the sample during transport to the surface. Filtration control agents preferably are added to the encapsulating material to prevent water from penetrating into or interacting with the core. These control agents prevent the loss and/or invasion of water or other gaseous or fluid components. The control agents are (a) a water soluble thickening agent, and, (b) a particulate sealing agent capable of (i) sealing the pores of the core sample, or (ii) bridging the pores of the core sample and permitting the thickening agent to adsorb to the bridge to seal the pores. The integrity of the core sample will be maximized if a pressure core barrel is used to transport the encapsulated core sample to the surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.