1 Calculate the hydrostatic pressure at the bottom of the fluid column for each case shown in Fig 4.52.
(Ans. 5200 psig for
Case A)
Given: D = 10,000 ft     ρ = 10 ppg                              Required: PA, PB, PC
Solution:
        CASE A: 𝑃𝐴 = 0.052 × 𝜌 × 𝐷                                       CASE B: 𝑃𝐵 = 0.052 × 𝜌 × 𝐷
                 𝑃𝐴 = 0.052 × 10𝑝𝑝𝑔 × 10,000𝑓𝑡                                       𝑃𝐵 = 0.052 × 10𝑝𝑝𝑔 × 10,000𝑓𝑡
                 𝑷𝑨 = 𝟓, 𝟐𝟎𝟎 𝒑𝒔𝒊                                                     𝑷𝑩 = 𝟓, 𝟐𝟎𝟎 𝒑𝒔𝒊
        CASE C: 𝑃𝐶 = 0.052 × 𝜌 × 𝐷
                 𝑃𝐶 = 0.052 × 10𝑝𝑝𝑔 × 10,000𝑓𝑡
                 𝑷𝑪 = 𝟓, 𝟐𝟎𝟎 𝒑𝒔𝒊
2 Calculate the mud density required to fracture stratum at 5,000 ft. if the fracture pressure is 3,800 psig. (Ans. 14.6
lbm/gal)
Given: D = 5,000 ft      PF = 3,800 psig
Required: ρmud
Solution:
                 𝑃𝐹
        𝜌=
             0.052 × 𝐷
                3,800 𝑝𝑠𝑖𝑔
        𝜌=
             0.052 × 5,000𝑓𝑡
        𝝆 = 𝟏𝟒. 𝟔𝟏𝟓𝟑𝟖𝟓 𝒑𝒑𝒈
3 An ideal gas has an average molecular weight of 20. What is the density of the gas at 2,000 psia and 600⁰R? (Ans. 0.8
Ibm/gal)
Given: MW = 20                                                   Solution:
        P = 2,000 psia                                                  𝑃 × 𝑀𝑊
                                                                 𝜌=
                                                                      80.3 × 𝑧 × 𝑇
        T = 600⁰R
        Z=1                                                            2,000 psia × 20
                                                                 𝜌=
                                                                      80.3 × 1 × 600⁰R
Required: ρ
                                                                 𝝆 = 𝟎. 𝟖𝟑𝟎𝟐𝟐𝟎 𝒍𝒃𝒎 ⁄𝒈𝒂𝒍