SPE67616
Phil.Dickson@PDGM.com
D
Along hole depth.
I
Wellbore inclination
Am
Wellbore azimuth referenced to magnetic north
At
Wellbore azimuth referenced to true north
Tf
Toolface angle
B
Magnetic field strength
Dip
Magnetic dip angle
Decl
Magnetic field dip azimuth
Z
Vertical depth
cos
Cosine of angle
sin
Cosine of angle
tan
Tangent of angle
arctan
Inverse tangent
cot
Cotangent
MDI
magnetic
plane angle
Some more words here
-sin(I) * sin(Am) * (cos(I) - tan(Dip) * sin(I) * cos(Am)) /
(1 - sin(I)**2 * sin(Am)**2)
MFI
magnetic
magnetic field strength
Some more words here
-sin(I) * sin(Am) * (tan(Dip) * cos(I) + sin(I) * cos(Am)) /
(B * (1 - sin(I)**2 * sin(Am)**2))
DBH
magnetic
magnetic field strength
Some more words here
1 / (B * cos(Dip))
DECL
magnetic
magnetic field strength
Some more words here
1
ABX
sensor
acceleration linear
Some more words here
(cos(I) * sin(Am) * sin(Tf) - cos(Am) * cos(Tf)) * tan(Dip) +
cot(I) * cos(Tf)
-cos(I) * sin(Tf)
ABY
sensor
acceleration linear
Some more words here
(cos(I) * sin(Am) * cos(Tf) + cos(Am) * sin(Tf)) * tan(Dip) -
cot(I) * sin(Tf)
-cos(I) * cos(Tf)
ABZ
sensor
acceleration linear
Some more words here
tan(Dip) * sin(I) * sin(Am) / G
-sin(I) / G
ASX
sensor
Some more words here
-(tan(Dip) * sin(I) * (cos(I) * sin(Am) * sin(Tf) - cos(Am) *
cos(Tf)) + cos(I) * cos(Tf)) * sin(Tf)
cos(I) * sin(I) * sin(Tf) ** 2
ASY
sensor
Some more words here
-(tan(Dip) * sin(I) * (cos(I) * sin(Am) * cos(Tf) + cos(Am) *
sin(Tf)) - cos(I) * sin(Tf)) * cos(Tf)
cos(I) * sin(I) * cos(Tf) * cos(Tf)
ASZ
sensor
Some more words here
tan(Dip) * sin(I) * cos(I) * sin(Am)
-sin(I) * cos(I)
ABIX
sensor
acceleration linear
Some more words here
(sin(I) * cos(I) ** 2 * sin(Am) * sin(Tf) * (tan(Dip) * cos(I)
+ sin(I) * cos(Am)) - cos(Tf) * (tan(Dip) * cos(Am) - cot(I)) ) /
(G * (1 - sin(I)**2 * sin(Am)**2))
-cos(I) * sin(Tf) / G
ABIY
sensor
acceleration linear
Some more words here
(sin(I) * cos(I) * cos(I) * sin(Am) * cos(Tf) * (tan(Dip) *
cos(I) + sin(I) * cos(Am)) + sin(Tf) * (tan(Dip) * cos(Am) -
cot(I)) ) / (G * (1 - sin(I)**2 * sin(Am)**2))
-cos(I) * cos(Tf) / G
ABIZ
sensor
acceleration linear
Some more words here
(sin(I) * cos(I) * sin(Am) * (tan(Dip) * cos(I) + sin(I) *
cos(Am))) / (G * (1 - sin(I)**2 * sin(Am)**2))
-sin(I) / G
ASIX
sensor
Some more words here
-sin(Tf) * (sin(I) * cos(I) * cos(I) * sin(Am) * sin(Tf) *
(tan(Dip) * cos(I) + sin(I) * cos(Am)) - cos(Tf) * (tan(Dip) *
sin(I) * cos(Am) - cos(I))) / (1 - sin(I)**2 * sin(Am)**2)
sin(I) * cos(I) * sin(Tf) * sin(Tf)
ASIY
sensor
Some more words here
-sin(Tf) * (sin(I) * cos(I) * cos(I) * sin(Am) * sin(Tf) *
(tan(Dip) * cos(I) + sin(I) * cos(Am)) - cos(Tf) * (tan(Dip) *
sin(I) * cos(Am) - cos(I)) / (1 - sin(I)**2 * sin(Am)**2)
sin(I) * cos(I) * cos(Tf) * cos(Tf)
ASIZ
sensor
Some more words here
cos(I) * (sin(I) * cos(I) * sin(Am) * (tan(Dip) * cos(I) +
sin(I) * cos(Am))) / (1 - sin(I)**2 * sin(Am)**2)
-sin(I) * cos(I)
MBX
sensor
magnetic field strength
Some more words here
(cos(Am) * cos(Tf) - cos(I) * sin(Am) * sin(Tf)) / (B *
cos(Dip))
MBY
sensor
magnetic field strength
Some more words here
-(cos(Am) * sin(Tf) + cos(I) * sin(Am) * cos(Tf)) / (B *
cos(Dip))
MBZ
sensor
magnetic field strength
Some more words here
-sin(I) * sin(Am) / (B * cos(Dip))
MSX
sensor
Some more words here
(cos(I) * cos(Am) * sin(Tf) - tan(Dip) * sin(I) * sin(Tf) +
sin(Am) * cos(Tf)) * (cos(Am) * cos(Tf) - cos(I) * sin(Am) *
sin(Tf))
MSY
sensor
Some more words here
-(cos(I) * cos(Am) * cos(Tf) - tan(Dip) * sin(I) * cos(Tf) -
sin(Am) * sin(Tf)) * (cos(Am) * sin(Tf) + cos(I) * sin(Am) *
cos(Tf))
MSZ
sensor
Some more words here
-(cos(I) * cos(Am) * cos(Tf) - tan(Dip) * sin(I) * cos(Tf) -
sin(Am) * sin(Tf)) * (cos(Am) * sin(Tf) + cos(I) * sin(Am) *
cos(Tf))
MBIX
sensor
magnetic field strength
Some more words here
-(cos(I) * sin(Am) * sin(Tf) - cos(Am) * cos(Tf)) / (B *
cos(Dip) * (1 - sin(I)**2 * sin(Am)**2))
MBIY
sensor
magnetic field strength
Some more words here
-(cos(I) * sin(Am) * cos(Tf) + cos(Am) * sin(Tf)) / (B *
cos(Dip) * (1 - sin(I)**2 * sin(Am)**2))
MSIX
sensor
Some more words here
-(cos(I) * cos(Am) * sin(Tf) - tan(Dip) * sin(I) * sin(Tf) +
sin(Am) * cos(Tf)) * (cos(I) * sin(Am) * sin(Tf) - cos(Am) *
cos(Tf)) / (1 - sin(I)**2 * sin(Am)**2)
MSIY
sensor
Some more words here
-(cos(I) * cos(Am) * cos(Tf) - tan(Dip) * sin(I) * cos(Tf) -
sin(Am) * sin(Tf)) * (cos(I) * sin(Am) * cos(Tf) + cos(Am) *
sin(Tf)) / (1 - sin(I)**2 * sin(Am)**2)
SAG
misalignment
plane angle
Some more words here
sin(I)
MX
misalignment
plane angle
Some more words here
-cos(Tf) / sin(I)
sin(Tf)
MY
misalignment
plane angle
Some more words here
sin(Tf) / sin(I)
cos(Tf)
AXINT
magnetic
plane angle
Some more words here
1
AMID
magnetic
plane angle
Some more words here
sin(I) * sin(Am)
DREF
depth
length
Some more words here
1
DSF
depth
Some more words here
D
DST
depth
length
Some more words here
D * Z
SPE90408
Phil.Dickson@PDGM.com
D
Along hole depth.
I
Wellbore inclination
Am
Wellbore azimuth referenced to magnetic north
At
Wellbore azimuth referenced to true north
Tf
Toolface angle
B
Magnetic field strength
Dip
Magnetic dip angle
Decl
Magnetic field dip azimuth
Z
Vertical depth
K
Switching factor for some tools. Then K = 1 when I
greater-than-or-equal-to 90, K = -1 when I greater-than 90
This behaviour is determined from the errorModel "switching" value.
NRF
Noise reduction factor at initialization.
This is the errorModel "noiseReductionFactor" value
Cant
Cant angle of tool. This is the errorModel "cantAngle" value
Lat
Latitude
W12
Misalignment weight for XYMIS1 and XYMIS2
Derived from errorModel "misalignmentMode" W12 = 1 when mode = 1, W12 = 0
when mode = 2 and W12 = sin(I) when mode = 3
W34
Misalignment weight for XYMIS3 and XYMIS4
Derived from errorModel "misalignmentMode" W34 = 0 when mode = 1, W34 = 1
when mode = 2 and W34 = cos(I) when mode = 3.
L
Interval length
Ip
Inclination at previous station
Tp
Computed value of error coefficient at previous station
C
Running speed of continuous survey
cos
Cosine of angle
sin
Cosine of angle
tan
Tangent of angle
arctan
Inverse tangent
cot
Cotangent
Erot
0.000072921158156
rad/s
Earth rotation rate
XYZACCBIASXY
sensor
plane angle
cos(I) / G
XYZACCBIASZ
sensor
plane angle
sin(I) / G
XYZACCSF
sensor
plane angle
1.3 * sin(I) * cos(I)
XYZACCMIS
sensor
plane angle
1.3 * sin(I) * cos(I)
XYACCBIAS
sensor
plane angle
1 / (G * cos(1 - K * Cant))
XYACCSF
sensor
1
XYACCMIS
sensor
plane angle
tan(1 - K * Cant)
XYACCGBIAS
sensor
plane angle
tan(1 - K * Cant) / G
XYACCBIAS
sensor
plane angle
1 / (G * tan(1 - K * Cant)
XYACCSF
sensor
plane angle
tan(1 - k * Cant)
XYGYROBIAS1
sensor
plane angle
sin(At) / (Erot * cos(Lat) * cos(I))
stationary
XYGYROBIAS2
sensor
plane angle
cos(At) / (Erot * cos(Lat))
stationary
XYGYRONOISE
sensor
plane angle
f * (sqrt(1 - cos(At)**2 * sin(I) ** 2) / (Erot * cos(Lat) *
cos(I)))
stationary
XYGYROGDEP1
sensor
plane angle
(cos(At) * sin(I)) / (Erot * cos(Lat)))
stationary
XYGYROGDEP2
sensor
plane angle
(cos(At) * cos(I)) / (Erot * cos(Lat)))
stationary
XYGYROGDEP3
sensor
plane angle
sin(At) / (Erot * cos(Lat)))
stationary
XYGYROGDEP4
sensor
plane angle
(sin(At) * tan(I)) / (Erot * cos(Lat)))
stationary
XYGYROSF
sensor
tan(Lat) * sin(At) * tan(I)
stationary
XYGYROMIS
sensor
plane angle
1 / (cos(Lat) * cos(I))
stationary
XYGYRODRIFT
sensor
angle per time
Tp + (1 / sin((Ip + I) / 2)) * (L / C)
continuous XY
EXTREF
reference
plane angle
Azimuth reference by fore-sighting or tie-on to an existing survey.
For the latter case, the external reference error has to be propagated
systematically across the existing and new surveys.
1
RDMTIE
reference
plane angle
1
TIEMIS
reference
plane angle
1 / sin(I)
DRAND
depth
length
1
DSYST
depth
length
1
DSCALE
depth
length
L
DSTRETCH
depth
length
(Z + D * cos(I)) * L
XYMIS1
misalignment
plane angle
W12
XYMIS2
misalignment
plane angle
-W12 / sin(I)
XYMIS3
misalignment
plane angle
-W34 * sin(At) / sin(I)
W34 * cos(At)
XYMIS4
misalignment
plane angle
W34 * cos(At) / sin(I)
W34 * sin(At)
VSAG
misalignment
plane angle
sin(I)
Large Oil Co Rev 1
Dr Ed O'Research
Am
Wellbore azimuth referenced to magnetic north
cos
Cosine of angle
FUD
magnetic
plane angle
Some additional peril arising from a sense of generalparanoia
cos(Am)
stationary
continuous Z