Novel ultralow-density cementing fluid

Abstract

The invention discloses an ultralow-density high-strength well cementing fluid which comprises the following components in percentage by mass: 10-30% of a modified perlite vitrified microbead lightening material, 60-75% of a reinforcing material, 5-9% of a coagulation accelerating early strength agent, 5-9% of a coagulation accelerating early strength additive and 10-15% of G-grade cement. The perlite vitrified microbeads in the lightweight material are subjected to surface treatment, and the components interact under a calcium-containing alkaline condition to realize physical and chemical reactions, so that the obtained mixture can realize good thixotropy and high coagulation strength; and in the using process, the ultra-low-density high-strength well cementing fluid and an ultra-low-density well cementing fluid leading slurry system (prepad fluid) can be obtained through the material proportion. The well cementing fluid leading slurry system has good compatibility with the drilling fluid, that is, the well cementing fluid leading slurry system is not afraid of pollution of the drilling fluid. Therefore, the replacement efficiency can be improved, the mixed slurry can be reduced and the well cementing quality can be improved by using the well cementing fluid leading slurry system for well cementation construction.

Description

technical field [0001] The invention belongs to the technical field of oil well cementing construction, and in particular relates to a novel ultra-low density cementing fluid. Background technique [0002] As we all know, during drilling operations, in order to protect casing, reduce cementing costs, and increase oil and gas production, low-density cementing fluid is usually used for cementing during well cementing. In particular, ultra-low and low-density cementing fluid with a cementing fluid density between 1.15 and 1.25 is a commonly used cementing material. In the current ultra-low density cementing fluid system with a density of 1.15-1.25, the lightening material is mainly artificial hollow glass microspheres. This artificial glass microsphere lightening material is at least 20,000 yuan per ton, and the price is high. So it cannot be promoted. Perlite vitrified microbead low-density cementing fluid system has relatively low cost, but there are many shortcomings in...

AI Technical Summary

Problems solved by technology

At present, there is no pre-fluid that meets the cementing requirements in China. The problem encountered is that the compatibility between the cementing fluid, the pre-fluid and the drilling fluid is poor. Insufficient return of well fluid, resulting in cementing quality problems