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Opt. Hyd.

HYDRAULICS

COMPUTER CALC. HAND CALC.inputs 4 x Bit dia. =______ + 5 = _______ G/B

Bit dia. 8.75 inches

ROP 60 ft per hr Bit dia. x Bit dia x 4 = ____ + 5 x Bit dia = ____ G

outputs Bit dia ^ 1.47 = _____ x 12.72 =______ Gmin

G/B 40 gpm/in.

G 350 gpm ROP / (.01 + .02) x ROP = _______ JvGmin 308 gpmJv 462 ft/sec

RULE:Balance flowrate between 25gpm and 50 gpm per inch of bit diameter. Jet velocity is influenced by formation drillabilityand mud overbalance chip hold down. The greater the overbalance the higher the jet velocity has to be to help free upthe chip that is being differentially held below the bit. The jet velocity range is usually between 250 and 450 ft./sec.

OPTIMUM HYDRAULICS:

The proper balance of hydraulic elements that will clean the hole below the bit, clean the bit and clean the bore holeabove the bit with minimum horsepower. The balance of the hydraulic elements is influenced by: 1) lost circulation(ECDeffect); 2) hole stability (turbulent erosion); 3) bit cleaning (cross flow); 4) cleaning hole below bit ( jet velocity) andcleaning the bore hole above the bit (annular velocity - flowrate - yield value and flow profile).

G/B = (4B)+5G = ((4(B^2)+(5B))Gmin = 12.72(B^1.47)Jv = ROP/(.01+.02)ROPWHERE:G/B = GPM/inch bit dia.G = GPM (flowrate, gpm)Gmin = For flowrate sensitive bits

(PDC, etc)B = Bit diameter, inchesJv = Jet velocity, ft./sec.ROP = Penetration rate

HYDRAULIC GUIDELINESHydraulics can be optimized by concentrating on four main guidelines:1)Flowrate; 2)Jet horsepower; 3)Percenthorsepower at the bit; 4)Jet velocity.

The rules listed below are based on running optimum bit weight.

RULE #1Maintain flowrate 30 - 50 gpm/in. of bit diameter. The following ROP ranges are general guidelines for flowratesrequired.

Range 1 - over 50 ft/hr 50 gpm/inRange 2 - 25 - 50 ft/hr 40 to 50 gpm/inRange 3 - 15 - 25 ft/hr 38 to 45 gpm/inRange 4 - 10 - 15 ft/hr 35 to 40 gpm/inRange 5 - 5 - 10 ft/hr 30 to 39 gpm/in

RULE #2Maintain jet horse power 2 1/2 to 5 HHP/in^2 (hydraulic horsepower per sq. in. of bit dia.).The rule is based on on thesquare root of the rate of penetration. In big hole (12 1/4 and greater size the HHP/in^2 could be allowed to go slightlyabove 5 (up to 6.5) if the drillability is good ( above 25 ft/hr).

RULE #3Design hydraulics so that 50 to 65% of available pump pressure is across the bit jet nozzles. If optimized at midrange(55 to 60) the driller has more flexibility with the flowrate as influenced by formation drillability, ECD, and drilling

operational factors.

RULE #4Maintain jet velocity between 350 and 450 ft/sec. Do not drop below 250 ft/sec. ROP and chip hold down influenceoptimum jet velocity as discussed in Optimum hydraulics above.

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Hyd. Calc.

WELL NAME COTROPIA GAS UNIT # 1

COUNTY RO

BIT# 5

Circulation Rate (Q) 225 gpm. Annular Velocity Dp (V) 218 ft/min

Diameter of Hole (Dh) 6.125 in. Annular Velocity Dc (V) 369 ftminOutside Diameter of Pipe O.D.(Dp) 3.5 in.

Inside Diameter of Pipe I.D.(Dp) 2.5 in. Surface Pressure Loss 7.3 psi

Length of pipe (Ldp) 8974 ft. Inside Pressure Loss (Dp) 1632.3 psiOutside Diameter of Collars O.D.(Dc) 4 3/4 in. Inside Pressure Loss (Dc) 474.0 psi

Inside Diameter of Collars I.D.(Dc) 2 in. Annular Pressure Loss (Dp) 251.3 psi

Length of Collars (Ldc) 881 ft. Annular Pressure Loss (Dc) 134.5 psiMud Weight (p) 10.8 ppg. Mud Motor Differential PSI 300.0 psi

Mud Motor Differential PSI 300 psi TOTAL SYSTEM LOSSES 2799.5Motor Rpm per Gallon 0.42 rpm

Surface Equip. Friction Factor(C) 0.15 Motor speed 94.5 rpm

TYPE 1(C)=1.00, TYPE 2(C)=.36, TYPE 3(C)=.22, TYPE 4(C)=.15

NOZZLE SELECTION (32nds) Decimal Equiv.Jet Nozzle #1 (32nds) 14 0.1503

Jet Nozzle #2 (32nds) 14 0.1503 Jet Nozzle Pressure Loss 248 psiJet Nozzle #3 (32nds) 14 0.1503 Nozzle Velocity 160.1 ft/sec

Jet Nozzle #4 (32nds) 0.0000 Estimated Stand Pipe Pressure 3047 psi

Jet Nozzle #5 (32nds) 0.0000 Jet Impact Force 200.7 lbfJet Nozzle #6 (32nds) 0.0000 Hydraulic Horse Power 32 hp

Hydraulic Horsepower per in^2 1.1 hsi

Surface Equip. Friction Factor (C)1 1.00 Calculated Standpipe Pressure 3047 psi

2 0.363 0.22

4 0.15This computer program is based on the Security Hydraulic Manual.

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Hyd. Worksheet

BIT HYDRAULIC ANALYSIS

HAND CALCULA TION WORKSHEET

Pb = GPM X^2 x MW x 156.5 / ( J1 X^2 + J2 X^2 + J3 X^2 ) X^2 =

HHPb = Pb x GPM / 1714 =

HHPb/in^2 = HHPb x 1.27 / BIT SIZE X^2 =

Vn = GPM x 417.2 / ( J1 X^2 + J2 X^2 + J3 X^2 =

I.F. = Vn x GPM x MW / 1932 =

I.F/IN^2 = I.F x 1.27 / BIT SIZE X^2 =

%PSI b = Pb / SURF. PSI =

SYSTEM HHP = SURF. PSI x GPM / 1714 =

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Ann. Flow

ANNULAR FLOW DYNAMICS

Hole Diameter 8 1/4 in. 600 Vicomter reading 12 cpsDrill pipe O.D. 4 1/2 in. 300 viscometer reading 8 cpsDrill Pipe Length 6138 ftFlowrate 302 gpm N 0.58 flow indexMud Wt. 8.8 lb/gal K 106.7 consistency indexPlastic Viscosity 4 P.V. Annular Velocity "A.V." 154.8 ft/minYeild Point. 4 Y.P. SEC^-1 99.0 rate of shear Cutting Diameter 0.5 in "U" Lam 15.8 apparent viscosity

"U" Turb. 39.3 apparent viscosityUse Larger "U" 39.3

FRICTION LOSS "^P" 7.6 psi/1000 ftREYNOLDS NO. "Rn" 4995.1CRITICAL VEL. "Cv" 2.35 ft/secCRITICAL VEL. "Cv" 141.0 ft/minCuttings Slip Velocity 66.2 ft/min

Cutting Rising Velocity 88.5 ft/minInterval Transport Time 39.7 mins

ANN. TRANSPORT TIME 43.2 mins

Hole Diameter 8 1/4 in. 600 Vicomter reading 12 cpsDrill Collar O.D. 6 1/4 in. 300 viscometer reading 8 cpsDrill Collar Length 655 ftFlowrate 302 gpm N 0.58 flow indexMud Wt. 8.8 lb/gal K 106.7 consistency indexPlastic Viscosity 4 P.V. Annular Velocity "A.V." 255.1 ft/minYeild Point. 4 Y.P. SEC^-1 306.2 rate of shear Cutting Diameter 0.5 in "U" Lam 9.9 apparent viscosity

"U" Turb. 34.5 apparent viscosity

Use Larger "U" 34.5FRICTION LOSS "^P" 38.8 psi/1000 ftREYNOLDS NO. "Rn" 7019.1CRITICAL VEL. "Cv" 2.47 ft/secCRITICAL VEL. "Cv" 148.5 ft/minCuttings Slip Velocity 69.2 ft/minCutting Rising Velocity 186.0 ft/minInterval Transport Time 3.5 ft/min

Note: Calculations b ased on Magob ar's Ann ular Flow Dynamics and

Bariod's Being ham Plastics Cri t ical Veloci ty

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Cost per Ft.

BIT COST PER FOOT

Rig Cost 400.00$ per hour Total cost 400.00$ per hour

Additional Cost -$ per hour Total Time 37.1 hoursBit Cost 5,000.00$Rotating Time 31 hours Bit Cost 36.88$ per foot

Connection Time 0.1 hoursTrip Time 6 hoursFootage Drilled 538 feet

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Sheet5

TUBING 0.00579 9526 55.2bha 0.0022 474 1.0

56.2annulus 0.0143 10000 143.0

199.2

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