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Mud Hydraulics Optimization 105

REFERENCES
Kendall, W.A., Goins, W.C., 1960. Design and operation of jet bit programs for
maximum hydraulics horsepower, impact force, or jet velocity. Trans. AIME 219,
238–247.
Speer, J.W., 1958. A method for determining optimum drilling techniques. Drill. Prod.
Prac. API, 130–147.
Sutko, A.A., Myers, G.M., 1970. The effect of nozzle size, number, and extension on the
pressure distribution under a tricone bit. SPE Paper 3109, presented at the Fall Meet-
ing of SPE of AIME, October, Houston.

PROBLEMS
4.1 Predict the parasitic pressure loss under the following conditions:
Total depth: 9,950 ft (3,036 m)
Casing: 9⅝ in, 43.5 lb/ft (8.755-in ID), set at 6,500 ft (1,982 m)
Open hole: 7⅞ in from 6,500 ft to 9,950 ft
Drill pipe: 9,500 ft of 4½-in, 16.6 lb/ft (3.826-in ID)
Drill collar: 450 ft of 6¾-in OD and 2¼-in ID
Surface equipment: Combination 4
3
Mud weight: 12.5 ppg (1,498 kg/m )
Plastic viscosity: 40 cp (0.04 Pa-s)
2 2
Yield point: 15 lb/100 ft (100 N/m )
3
Mud flow rate: 350 gpm (1.33 m /min)
4.2 For the data in Problem 4.1, select a liner size for two TSC WF700
Triplex pumps. Assume the flow rate exponent m = 1.75 and the
maximum bit hydraulic horsepower criterion. Additional data are
given as follows:
Cuttings specific gravity: 2.65 water = 1
Particle sphericity: 0.80 ball = 1
Rate of penetration: 70 ft/hr (21.3 m/hr)
Rotary speed: 60 rpm
Cuttings concentration: 8%
4.3 For the data in Problems 4.1 and 4.2, design the mud flow rates and the
bit nozzle sizes at depths from 6,500 ft (1,981 m) to 9,950 ft (3,033 m).
4.4 Using the data given in Problem 4.1 and the maximum bit hydraulic
power criterion, calculate the required pump pressure and select a
pump from Table 3.6.
4.5 Using the data given in Problem 4.1 and the maximum bit hydraulic
jet impact force criterion, calculate the required pump pressure and
select a pump from Table 3.6.