Dry blend pre-flush and spacer package and method for mixing and injecting a pre-flush and spacer on-the-fly to clean a subterranean well

US11078399B2 · kind B2 · utility

Inventors

• Simon Iremonger · Calgary, CA
• Jared Taylor · Eden Prairie, US

Key dates

• Filing date: Jun 28, 2019
• Grant date: Aug 3, 2021
• Expiry date: Mar 26, 2040

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E21B37/00
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to a dry blend one-part pre-flush and spacer package for forming a water-based pre-flush and spacer on-the-fly for use in a subterranean well and a method of mixing a pre-flush and spacer on-the-fly for use in a subterranean well. The dry blend pre-flush and spacer package includes an anionic surfactant, a builder compound, and optionally, a defoamer, a dispersant calcium chelator, a density modifying agent, a viscosifying agent such as a solid, and preferably rapidly hydrating, gellant, salt and one or more lost-circulation materials. The dry blend pre-flush and spacer package is mixed on-the-fly with water at the subterranean well site to form the pre-flush and spacer at a pre-selected density and the pre-flush and spacer, when pumped into the subterranean well by a pressure pumper, converts the well from an oil-wet or substantially non-water-wet condition to a substantially water-wet condition.