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INPUT   DATA

♥ EXAMPLE Of Input/Output

Title

LOG    READINGS

Sub- interval	Top- Depth	Bottom- Depth	Gamma- Ray	D.Laterolog Resistivity	S.Laterolog Resistivity	Micro log Resistivity	Density- Porosity	Neutron- Porosity	Sonic- Porosity
	(ft)	(ft)	API	ohm-m
1
2
3
4
5
6
7
8
9
10

Max recorded Temp.		° F
Depth of Max Temp.		ft
Mud Filtrate Resistivity		ohm-m
Temp. of Mud Filtrate		° F
Surface Temp.		° F
Geothermal Gradient		° F / ft; 0 ⇒ compute internally
Max Gamma Ray reading
Min Gamma Ray reading
Corrected SP Reading
Formation Water Resistivity		0 ⇒ compute internally
Temp @ Water Resistivity		° F
Formation Water Salinity		ppm; 0 ⇒ compute internally
Water Saturation Cut-off
Shale Fraction Cut-off
Density Porosity Cut-off
Resistivity of Shale		0 ⇒ compute internally
Clay Porosity		0 ⇒ default (0.3)

Shaley Sand Analysis ?	Yes No
Two-Porosity Analysis ?	Yes No
Three-Porosity Analysis ?	Yes No
Lithology Type	Clean Sand Shaley Sand Calcareous Carbonates

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OUTPUT   VARIABLES   &   GRAPHS

Formation Water Resistivity
Net Pay Thickness	ft
Average Porosity
Average Water Sat.

Sub- interval

Top- Depth

Bottom- Depth

Density Porosity

Water Sat (Archie method)

Water Sat (Ratio method)

Movable Oil Index;

Water Sat (Shaley Sand method)

Water Sat (3-poro method)

Water Sat (2-poro method)

Shale Content

Compaction Correction Factor

Formation Water Resistivity

Formation Water Salinity

Hydro- carbon Index

Bulk Vol Fraction Water

(ft)

(ft)

(ppm)

1

2

3

:

:

9

10

Conventional Well Log Analysis II

(*** Note that Analysis II requires Dual laterolog with a Microfocused log, whereas Analysis I requires Dual induction laterolog.)

Performs performs conventional well log analysis on up to 10 sub-intervals .

The required Logs are:
  -  Dual Laterolog (deep & shallow) with a Microfocused log
  -  Porosity Logs (density, neutron & sonic)
  -  Gamma Ray & SP

The program provides water saturation estimates based on the following calculation methods:
   -  Archie,
   -  Ratio,
   -  2-porosity,
   -  3-porosity and
   -  Shaley-sand.

It also computes porosities, hydrocarbon index and movable oil index. In addition, it provides average values of porosity, water saturation, and net pay thickness for the interval based on user selected cut-off parameters.

User can select from 4 Lithology types:
   -  average sand,
  -  shaley sand,
  -  calcareous sand and
  - carbonates.

The underlying formulae are:

where

  F = Formation factor,

  φ = Porosity, fraction

  S_WA = Water saturation by Archie method, fraction

  S_WR = Water saturation by Ratio method, fraction

  φ_s = Sonic porosity, fraction

  φ_e = Effective porosity, fraction

  φ _Z = Total porosity of the sand matrix, including pore fluids and clay

  q = Shale/slit fraction in the rock

  C_p = Compaction factor

  S_gxo = Residual hydrocarbon saturation in the zone close to the borehole

  φ_N = Neutron porosity, fraction

  φ_D = Density porosity, fraction

  S_WTH = Water saturation by the 3-porosity method, fraction

  S_WTW = Water saturation by the 2-porosity method, fraction

  V_SH = Shale fraction

  φ _NC = Corrected neutron porosity, fraction

  φ _DC = Corrected density porosity, fraction

  φ _ND = Average neutron-density porosity, fraction

  S_WSH = Water saturation by the Shaley sand method, fraction

  R_SH = Resistivity of shale

  R_W = Resistivity of formation water

  R_T = Formation resistivity

  φ _clay = Porosity of shale, fraction

BIBLIOGRAPHY

• Sinha M.K. & Padget L.R.; Reservoir Engineering Techniques Using Fortran; IHRD Corp, Boston, 1985, chap. I.3.
• Mian M.A.; Petroleum Engineering Handbook For the Practicing Engineer; Pennwell Publ Co, Tulsa, 1992, vol I, chap. 3.