Method and composition for preserving core sample integrity using an encapsulating material
US5360074A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1993 |
| Grant date | Nov 1, 1994 |
| Priority date | — |
| Expiry date | Apr 21, 2013 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B25/08
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention provides a method for maintaining the mechanical integrity and for maximizing the chemical integrity of a core sample during transport from a subterranean formation to the surface. The method involves cutting and encapsulating a core sample with an encapsulating material that increases in viscosity or even solidifies, at temperatures slightly lower than those expected downhole, or relatively early in the transport process. A preferred encapsulating material contains at least one polyglycol or chemically modified polyglycol from the oxyalkylene polymer family. The specific formulation of the encapsulating material differs depending upon the expected downhole conditions. For example, the encapsulating material can include a thickener, a nucleating agent, and a water swellable material or another inert material that is capable of sealing the core sample against water. A preferred nucleating agent would serve both as a heat transfer agent and a crystallization trigger, and therefore would speed up the rate at which the encapsulating material would solidify or increase in viscosity, particularly downhole. The encapsulating material should either solidify or increas…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.