Page 143 - Formulas and Calculations for Petroleum Engineering

136 Formulas and calculations for petroleum engineering

Formula(s)

n
τ ¼ τ +K gðÞ
y
Reference: Samuel. E Robello. 501 Solved Problems and Calculations for Drilling Operations. Sigma Quadrant. 2015.
Houston, Texas, Page: 185.
2.145 Mud rheology—Power-law model—Consistency index

Input(s)

y a : Fann Dial Reading at 300 Rpm (cP)
n: Power-Law index (dimensionless)

Output(s)

K: Consistency index (cP)

Formula(s)

510 y a
K ¼ n
511
Reference: Samuel. E Robello. 501 Solved Problems and Calculations for Drilling Operations. Sigma Quadrant. 2015.
Houston, Texas, Page: 194.
2.146 Mud rheology—Power-law model—Power-law index

Input(s)
y a : Fann Dial Reading at 600 Rpm (cP)
y b : Fann Dial Reading at 300 Rpm (cP)

Output(s)
n: Power Law index (dimensionless)

Formula(s)

n ¼ 3:322 log y b
y a
Reference: Samuel. E Robello. 501 Solved Problems and Calculations for Drilling Operations. Sigma Quadrant. 2015.
Houston, Texas, Page: 194.
2.147 Mud rheology—Power-law

Input(s)

K: Consistency Index (cP)
n: Power-Law Index (fraction)
g: Shear Rate (1/s)

Output(s)
2
τ: Shear Stress (lbf/100 ft )