Cementing slurry and method of designing a formulation
AssigneeSchlumberger Technology Corporation
InventorsJohn Villar, Jean-Francois Baret
Life of this patent
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Abstract
The present invention provides a cementing composition for an oil or analogous well, essentially constituted by a solid fraction suspended in a liquid medium. The solid fraction is constituted by a coarse fraction with a packing volume fraction .PHI..sub.1 which, according to the invention, is maximised, and a fines fraction x with a packing volume fraction .PHI..sub.2 which is less than or equal to the volume fraction x.sub.0 such that ##EQU1## The invention also provides a method of maximising the value of .PHI..sub.1. The invention can minimise fluid loss whatever the materials selected for a cementing composition.
Claims10
A well cement composition for use in performing cementing operations in a subterranean zone comprising a solid fraction of particles suspended in a liquid medium, the solid fraction consisting essentially of a coarse fraction and a fines fraction composed of fines particles having an average diameter less than 1 .mu.m, the coarse fraction being comprised of the solid particles in the liquid medium other than the fines particles, the packing volume fraction .PHI..sub.1 of the coarse fraction being greater than 0.8, and the solid volume fraction x of the fines particles being less than or equal to the volume fraction x.sub.0 such that ##EQU5## in which .PHI..sub.2 is the packing volume fraction of the species constituted solely by the fines particles.
A well cement composition for use in performing cementing operations in a subterranean zone prepared by suspending solid particles in a liquid medium to form a solid fraction in the liquid medium, the solid fraction consisting essentially of a coarse fraction and a fines fraction composed of fines particles having an average diameter less than 1.mu., the coarse fraction being comprised of the solid particles in the liquid medium other than the fines particles, the packing volume fraction .PHI..sub.1 of the coarse fraction being greater than 0.8, and the solid volume fraction x of the fines particles being less than or equal to the volume fraction x.sub.0 which equals ##EQU6## in which .PHI..sub.2 is the packing volume fraction of the fines particles.
Dependencies are inferred from the claim text.