Composition of base fluid and polymeric dispersing agent-absorbed polymer-coated colloidal particles
US7727939B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2004 |
| Grant date | Jun 1, 2010 |
| Priority date | — |
| Expiry date | Jan 24, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S507/906
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method of controlling the pressure of a casing annulus in a subterranean well that includes injecting into the casing annulus a composition including a base fluid and a polymer coated colloidal solid material. The polymer coated colloidal solid material includes: a solid particle having an weight average particle diameter (d50) of less than two microns, and a polymeric dispersing agent coated onto the surface of the solid particle during the cominution (i.e. grinding) process utilized to make the colloidal particles. The polymeric dispersing agent may be a water soluble polymer having a molecular weight of at least 2000 Daltons. The solid particulate material may be selected from materials having of specific gravity of at least 2.68 and preferably the solid particulate material may be selected from barium sulfate (barite), calcium carbonate, dolomite, ilmenite, hematite, olivine, siderite, strontium sulfate, combinations and mixtures of these and other similar solids that should be apparent to one of skill in the art.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.