Rheological model of mud
Release time: 2015/10/27 Ai Yi NewsViews : 1295
In drilling, selecting reasonable mud is one of the important conditions for successful drilling. Selecting excellent mud properties, rheological properties and hydraulic properties is an important means to improve the efficiency of drilling fluids. It has important effects on the feed, powder discharge, hole wall stability, drilling loss and flow resistance (pressure loss). However, the rheological properties of mud vary widely, different rheological modes have different rheological properties, and their rheological parameters are not the same. The excellent choice of mud rheological modes is not only important for accurate calculation of rheological parameters, It also plays an important role in evaluating the performance of the treatment agent, optimizing the drilling hydraulic parameters, analyzing and purifying the wellbore and the stability of the wellbore. Currently, the widely used mud rheological modes include Bingham mode, power law mode, Carson mode, and Herba mode .
1. Bingham mode:
Plastic fluid can be called Bingham fluid. Its rheological curve is a straight line that does not pass through the origin. This fluid has a certain particle concentration and forms an internal structure between particles in a static state. When external force is applied to shear, Destroy the junction plastic viscosity.
2. Power-law mode:
The rheological curve of a power-law fluid is a curve that passes through the origin and can be represented by a dense function or a power-law mode.
3. Carson model:
The Carson model can accurately predict viscosity changes at high or very high shear rates based on data from low and medium shear rates. The Carson mode is assumed to condense into long rods that can be decomposed into original particles at shear rates, especially at high shear rates.
4. Herba mode:
The Herba model includes pseudoplastic fluid with yield value and expanded fluid with yield value.