文档介绍：WELL CONTROL
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Well Control
Class Problem
¾ Depth (TVD) = 8000 ft Mud Wt = ppg
¾ SIDPP, Pdp = 300 psi SICP, Pa = 450 psi
¾ Reduced (slow) pump pressure, Pc = 850 psi
¾ Reduced (slow) pump rate = 170 gpm ( bpm)
¾ Pump ou tput = 3 . 3 ga l/s tro ke (0. 0786 bbls /s tk)
¾ Drill pipe = 4 ½” OD by ” ID ( bbls/ft)
¾ Drill collars = 6 ¼” OD by 2 ¾” ID, 463 feet
( bbls/ft)
¾ Hole size = 8 ¾”
Determine
¾ Kill mud weight
¾ Initial circulating pressure
¾ FilFinal c ircu ltilating pressure (Wit(Wait an dWiht)d Weight)
¾ Drill pipe pressure schedule (Wait and Weight)
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Wait and Weight Method
Determine the density of the kill
weight mud
Bottomhole pressure = 0. 052 x
x 8000 +300 = 4626 psi
Density of kill weight mud =
4626/(8000 x ) = ppg
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Wait and Weight Method
Initial circulating pressure = 300
+ 850 = 1150 psi
Final circulating pressure =
() x 850 = 915 psi
Determine the strokes to bit
Pump output = ( gals/stk) /(42
gals/bbl) = bbls/stk
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Wait and Weight Method
Capacity DP = ( /1029) x
(8000 – 463) = bbls
Cappyacity of drill collars = (
/1029) x 463 = bbls
Total capacity = 107. 22 + 3. 40 =
bbls
Strokes to bit = 110 .62 bbls /
bbls per stroke = 1408
strokes
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Wait and Weight Method
Calculate the reduction in
pressure per 200 strokes
[(1150 – 915)/1408] x 200 = 33 psi
per 200 strokes
Construct a drill pipe pressure
reduction schedule
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Wait and Weight Method
Strokes Pressure
0 1150
200 1117
400 1084
600 1051
800 1018
1000 985
1200 952
1400 919
1408 915
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