Non-invasive time-based sag testing apparatus

Patent metadata

Field	Value
Publication number	US-11840926-B2
Application number	US-202117488000-A
Country	US
Kind code	B2
Filing date	Sep 28, 2021
Priority date	Sep 28, 2021
Publication date	Dec 12, 2023
Grant date	Dec 12, 2023

Abstract

Time-based sag in a fluid can be measured non-invasively using a time-based sag testing apparatus by measuring the change in rotational inertia over time of fluid having no initial density gradient and a center of mass initially coincident with its geometric center.

First claim

What is claimed is:

1. A non-invasive method for measuring time-based sag in a fluid having a mass, the method comprising:
providing a test cell that contains the fluid, where the test cell comprises an original center of mass and a lateral axis extending through the original center of mass;
after a time period sufficient for fluid sag to occur, rotating the test cell about the lateral axis from an initial vertical position to a non-vertical position;
measuring the static torque required to hold the test cell at the non-vertical position; and
using the measured torque to determine the distance from the original center of mass to a resultant center of mass, the distance being directly proportional to time-based sag.

2. The method of claim 1 where the test cell is filled with the fluid such that the test cell has no vapor space.

3. The method of claim 1 where the step of rotating the test cell comprises rotating the test cell about the lateral axis less than 90°.

4. The method of claim 1 comprising comparing the measured torque to a set of reference standards determining displacement of the center of mass.

5. The method of claim 1 where the fluid is a drilling fluid.

Assignees

• Baker Hughes Oilfield Operations Llc

Inventors

• Everhard Eliah M

Classifications

• G01N33/2823

  Raw oil, drilling fluid or polyphasic mixtures · CPC title

• G01N15/04

  Investigating sedimentation of particle suspensions · CPC title

• G01N2015/0092

  Monitoring flocculation or agglomeration · CPC title

• G01N2015/0061

  in solids, e.g. petrography · CPC title

• G01N11/00

  Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties · CPC title