[...]... most fluids than the simpler Power Law and Bingham models Therefore, it is being widely used for hydraulics calculations both by Baker Hughes Drilling Fluids and other companies Difficulties are still experienced making correlations between drilling fluid parameters measured in the field and hydraulic calculations Reference Manual 1-20 Baker Hughes Drilling Fluids Revised 2006 Baker Hughes Drilling Fluids. .. sec – 1 ft sec Reference Manual 1-6 Baker Hughes Drilling Fluids Revised 2006 Baker Hughes Drilling Fluids Newtonian and Non-Newtonian Fluids The relationship between shear stress ( τ ) and shear rate ( γ ) defines the flow behavior of a fluid for some fluids, the relationship is linear If the shear rate is doubled, then the shear stress will also double Such fluids are called Newtonian fluids Examples... generated during drilling and after the well is finished Careful attention to the composition of the fluid and the handling of the residual materials reduces the potential environmental impact of the drilling operation Reference Manual 1-4 Baker Hughes Drilling Fluids Revised 2006 Baker Hughes Drilling Fluids Physical and Chemical Properties of Fluids The physical and chemical properties of a drilling fluid... For drilling fluids, the pseudo plastic behavior is applicable and is characterized when n is between zero and one Pseudo plastic fluids exhibit shear thinning, where the effective viscosity decreases as the shear rate increases just like the Bingham Plastic Model Figure 1-11 shows the flow curves for these values of n Reference Manual 1-16 Baker Hughes Drilling Fluids Revised 2006 Baker Hughes Drilling. .. ⎞ ⎝ 300 ⎠ where, θ = dial reading YP = yield point PV = plastic viscosity ώ = rotation speed (rpm) Figure 1-9 Reference Manual 1-14 Fann Model 35A 6 Speed V-G Meter Baker Hughes Drilling Fluids Revised 2006 Baker Hughes Drilling Fluids As defined in the Fluids Testing Procedures Manual, the determination of PV and YP are obtained from the dial readings at 600 rpm and 300 rpm Substitution of the... filtrate test in the range of 2:1 to 4:1, whereas a system comprised of a high concentration of drilled solids may have a ratio of 10:1 or higher Obviously, a Reference Manual 1-22 Baker Hughes Drilling Fluids Revised 2006 Baker Hughes Drilling Fluids drilling fluid could exhibit a low API filtrate value at 100 psi and ambient temperature and an extremely high filtrate (thick wall cake) on the HT/HP test... Log 511 – log 5.11 600 rpm na n Log Θ600 – Log Θ300 np Log Θ300 – log Θ3 Log Θ3 3 rpm LOG DIAL READING, Θ Log Θ300 1000 SHEAR RATE, Ў Figure 1-13 Reference Manual 1-18 Determination of n and K Baker Hughes Drilling Fluids Revised 2006 Baker Hughes Drilling Fluids Table 1-1 shows the corresponding shear rate in reciprocal seconds to the V-G meter speed in rpm, with standard Rotor-Bob spring combination... very similar to that of a Newtonian fluid with the exception that some portion of the cylindrical shells in the center of a pipe may not slide past one another Reference Manual 1-8 Baker Hughes Drilling Fluids Revised 2006 Baker Hughes Drilling Fluids Figure 1-4 Two Dimensional Velocity Profiles of Laminar Flow for a Non-Newtonian Fluid The two dimensional velocity profile of a non-Newtonian fluid in... relationship for the Bingham Plastic Model is given by: τ = τ o + ( μ ∞ ) (γ ) where, τ = shear stress τo = yield point μ∞ = Plastic viscosity γ = shear rate Reference Manual 1-12 Baker Hughes Drilling Fluids Revised 2006 Baker Hughes Drilling Fluids The flow curve for a Bingham Plastic fluid is illustrated in Figure 1-8 The effective viscosity, defined as the shear stress divided by the shear rate,... polymers on the filtration rate One must know, or have measured, the effects of polymer additions on the viscosity of the filtrate in order to make such predictions Reference Manual 1-24 Baker Hughes Drilling Fluids Revised 2006 Baker Hughes Drilling Fluids Time The calculation of filtrate loss at variable time intervals relative to known filtrate loss and time interval can be predicted by the following equation: . Models 1-2 0 Casson 1-2 0 Robertson-Stiff 1-2 0 Herschel-Bulkley 1-2 0 Table of Content Reference Manual Baker Hughes Drilling Fluids ii Revised 2006 Gel Strengths 1-2 1 Filtration 1-2 2 Testing. Analysis 1-2 9 Summary 1-3 0 Drilling Fluids pH and Alkalinity 1-3 0 Example Calculations 1-3 3 Parameters 1-3 3 Exercise 1-3 3 Drill-In Fluids 1-3 4 Function 1-3 4 Development 1-3 4 Attributes 1-3 4. 1-3 9 Filter Cake Formation and Dispersability 1-3 9 Baker Hughes Drilling Fluids Baker Hughes Drilling Fluids Reference Manual Revised 2006 iii Return Permeability vs. Breakout Pressure 1-4 2