DIRECTIONAL & HORIZONTAL DRILLING EQUATIONS
TRIANGLES:
Sin = Opp
Hyp
Cos = Adj
Hyp
Opp = Sin x Hyp
Tan = Opp
Adj
Hyp = Opp
Sin
Hyp = Adj
Cos
Adj = Cos x Hyp
CIRCLES:
Curvature or BUR = 5730
RC
RC = 5730
BUR
TVD = RC x (Sin INC2 – Sin INC1)
VS = RC x (Cos INC1 – Cos INC2)
MD = RC x 2 x Pi x (INC2 – INC1) = RC x (INC2-INC1)
360
57.3
VBURREQ = 5730 x Sin Target INC – Sin Current Inc
Target TVD – Current TVD
VBUR = 100 x (INC2 – INC1)
MD2 – MD1
VBURACTUAL = (Cos TFO) x DLTOTAL
TVDDIP = Vertical Section x (Tan 90 + Dip)
PBIT = MW x (GPM)2
TFANOZZLES = MW x (GPM)2
10859 (Pbit)
10859 (TFA)2
HHP = Pbit x GPM
1714
DoglegOreinted =
HSI = HHP
Area Hole
AREAHole = 0.7854 (Dia)2
200 x Bit Tilt
Length of Bit to Top Stabilizer
Angle Change = BUR x CL
100
CL = Angle Change x 100
BUR
BUR / 100’ = Change In Angle x 100
CL
DLS / FT = Angle Change
CL
Projected TVD @ Bit = RC x(Sin INC2 – Sin INC1) + Existing TVD
BUR Needed to Target = (Sin Desired Angle – Sin Present Angle) x
5730______________
(Target TVD – Current TVD)
DLS / 100’ = (Cos last INC x Cos new INC) + (Sin last INC x Sin new INC) x
Cos Directional Difference = Cos-1 x 100
CL
Projected Angle Needed to Reach Target = Target TVD – Present TVD =
Arc Tangent of Angle.
Usable VS
Add to 90 deg. if Angle is over 90 deg. Subtract if Angle is under 90 deg.
Usable VS = Target VS – Present VS
Projected BUR From TF Setting = BUR = Cos Avg. TF x DL
Projected MD = Target INC – Last INC
DLS/Ft
To Find CL When You Know BUR & Angle Needed = Angle Needed
BUR
= CL
100
To Find
BUR When You Know The TVD, INC1 & INC2 = 5730 / _ TVD (usable)____
Sin INC2 – Sin INC1
CL Angle = Divide by N or S to Get Tangent of Angle (Inv. Tangent-1)
CL Distance = Take CL Angle if over 45 deg Find Sin of Angle & Divide it into the
Largest Coordinate to get Distance. If Angle is Below 45 deg Use Cos of Angle &
Divide it into the Largest Coordinate.
TF Setting = Angle Change Arc Cos
DLS
CL Distance = (NS)2 + (EW)2
Formation Dip in Feet = Tangent of Formation Dip x VS
Bit Angle Projection = Take BUR of Last Survey x CL Divide by 100 = Angle
change. Add Angle Change to Last Survey.
Bit Direction Projection = Take the Difference of Last 2 Surveys Divide by CL of
Last Survey = Direction Change per Foot x Projected CL. Then Add or Subtract
From Last Survey Direction.