Petroleum Engineering - PENG 3301
Drilling Engineering - Homework #5
Due Date: 11/05/2014
@ 1,850 ft of 13-3/8-in., 48 lb/ft
@ 8,643 ft of 9-5/8-in., 32.30 lb/ft
ID = 9.001-in.
@ 8,300 to 14,500 ft of 7-in., 20 lb/ft
ID = 6.456-in.
Bit diameter = 6-1/8-in.
Hole Depth = 17,800 ft
5-in. d/p, 19.50 lb/ft (ID = 4.276-in.) to 8,000 ft
3½-in. 13.3 lb/ft (ID = 2.764-in.) to 16,800 ft
1,000 ft of 4¼-in. OD x 2¾-in. ID d/c
3 pits (H = 7 ft, W = 6 ft, L = 31 ft)
Two pits: 64 in. of mud
One pit: 46 in. of mud
Mud weight: 16.3 ppg
5-in. OD, 4.276-in. ID:
Capacity = 4.276² / 1029 = 0.0178 bbl/ft
Displacement = (5² - 4.276²) / 1029 = 0.0065 bbl/ft
3.5-in. OD, 2.764-in. ID:
Capacity = 2.764² / 1029 = 0.0074 bbl/ft
Displacement = (3.5² - 2.764²) / 1029 = 0.0045 bbl/ft
4-in. OD, 2.2475-in. ID:
Capacity = 2.2475² / 1029 = 0.0049 bbl/ft
Displacement = (4² - 2.2475²) / 1029 = 0.01064 bbl/ft
13.375-in. casing capacity = 12.715² / 1029 = 0.157 bbl/ft
9.375-in. casing capacity = 9.001² / 1029 = 0.0787 bbl/ft
7-in. liner capacity = 6.456² / 1029 = 0.0405 bbl/ft
6.125-in. hole capacity = 6.125² / 1029 = 0.0365 bbl/ft
Vwell = (0.0787 × 8,300 ft) + (0.0405 × 6,200 ft) + (0.0365 × 3,300 ft)
Vwell = 653.31 + 251.10 + 120.45 = 1,024.86 bbl
VDS = (0.0065 × 8,000 ft) + (0.0045 × 8,800 ft) + (0.01064 × 1,000 ft)
VDS = 52 + 39.6 + 10.64 = 102.24 bbl
Mud Volume in Hole = Vwell - VDS
= 1,024.86 - 102.24 = 922.62 bbl
Tank 1 & 2: 31 ft × 6 ft × (64/12 ft) = 992 ft³ each
Tank 3: 31 ft × 6 ft × (46/12 ft) = 713.67 ft³
Total = 992 + 992 + 713.67 = 2,697.67 ft³
= 480.30 bbl (1 bbl = 5.615 ft³)
Total Mud Volume = Pit Volume + Hole Volume
= 480.30 + 922.62 = 1,402.92 bbl
Required: 25 lbm/bbl
Mass = 25 lb/bbl × 1,403 bbl = 35,075 lb
Number of sacks = 35,075 / 50 lb/sack = 702 sacks
Volume = 35,075 lb / 22 lb/gal = 1,594.32 gal = 38 bbl
Vbarite + Vwater + Vgel = Vfinal
Vbarite + Vwater + 38 = 1,403
Vbarite = 1,365 - Vwater
ρbarite × Vbarite + ρwater × Vwater + ρgel × Vgel = ρfinal × Vfinal
35 × Vbarite + 8.35 × Vwater + 22 × 38 = 16.3 × 1,403
35 × (1,365 - Vwater) + 8.35 × Vwater + 836 = 22,869
47,775 - 35 × Vwater + 8.35 × Vwater + 836 = 22,869
48,611 - 26.65 × Vwater = 22,869
26.65 × Vwater = 25,742
Water Volume:
Vwater = 966 bbl
Barite Volume:
Vbarite = 1,365 - 966 = 399 bbl
Mass = 399 × 42 gal/bbl × 35 lb/gal = 586,530 lb
= 5,866 sacks (100 lb/sack)
Ph = 0.052 × MW × h
Where: MW = mud weight (ppg), h = depth (ft)
Ph = 0.052 × 16.3 ppg × 17,800 ft
Hydrostatic Pressure = 15,087 psi
a) Mud volume in hole:
922.62 bbl
b) Total mud volume:
1,403 bbl
c) Bentonite needed:
702 sacks
d) Barite weight:
586,530 lb
e) Barite sacks:
5,866 sacks
f) Water needed:
966 bbl
g) Hydrostatic pressure:
15,087 psi
Study hard and ace your drilling engineering course!