HELP: PfEFFER-java PfEFFER File Organization

A single Excel workbook is used to organize all the well log information for a particular well. We will refer to this workbook as a well workbook (even when the well is a dry hole). Each well workbook contains unit worksheets. A unit is a stratigraphic subdivision as defined by a user. So, a unit may be a formal geologic formation, a reservoir interval, or a reservoir subdivision. Logging data may be downloaded for multiple units from LAS File(s), see Importing LAS Files

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Home Area Selected Log Curves and Data Values

Archie & Other Parameters panel

Variable Description Flow Unit Name of flow unit Depth Start Minimum depth of flow unit interval End Start Maximum depth of flow unit interval Archie Equation Sw = ( A*Rw Rt*ΦM ) 1/N     Archie Equation Parameters Variable Description A Archie constant M Cementation exponent N Saturation exponent Rw Formation water resistivity at formation temperature Rsh Shale resistivity used in shaly sand computations PHIsh Shale porosity used in shaly sand computations Archie Equation for Moveable Hydrocarbon Sxo = ( A*Rmf Rxo*ΦM ) 1/N     Moveable Hydrocarbon Parameters Variable Description Rmf Mud Filtrate Resistivity @ Temperature Total Depth Total Depth of Well Surface Temp Surface temperature [Default same as Mud Filtrate Temperature (Rmft)] Bottom Temp Bottom hole temperature Cut-Offs A zone is considered pay if PHI < Phi Cut; SW < Sw Cut; VSH < Vsh Cut; and BVW < Bvw Cut. If all these criteria are satisfied of oil (THK*PHI*(1-SW)). Otherwise the value of PAY is set to zero. The default values for these cut-offs are 0,1,1 and 1 (for PHI, SW, VSH and BVW, respectively). Variable Description PHI Cut Porosity Cut Off is not pay if PHI > Porosity cut off. Sw Cut Water Saturation Cut Off is not pay if SW < Water Saturation cut off. Vsh Cut V-Shale Cut Off is not pay if VSH < V-Shale cut off. Bvw Cut Bulk Volume Water Cut Off is not pay if BVW < Bulk Volume Water cut off. Cumulative Values (Computed) Variable Description CTHK Cumulative unit thickness summed from THK Column FTOIL Cumulative feet (or meters) of oil (or gas) in PAY Column PAYFEET Cumulative feet (or meters) of section considered to be pay AVPHI Average Porosity (Φ), computed as a simple average of the porosities in PHI Column AVSW Average Water Saturation (Sw), computed as a simple average of the water saturations in SW Column Wyllie-Rose Equation k = PΦQ SwiR P, Q and R: parameters of the Wyllie-Rose equation used to estimate permeability (k) from porosity (Φ) and irreducible water-saturation (Swi)

Home Area

Home Area Columns
Mnemonic	Name	Description
RT	True resistivity	Choice of resistivity log to be used is at the discretion of the user.
PHI	"True porosity"	PHI must contain fractional (as opposed to percentage) data and is generally equated with "true porosity". At the user’s discretion, PHI can be derived from a single porosity log (sonic, density, or neutron) stored in the log columns or computed as a function of several porosity logs.
RWA	Reconnaissance (apparent) water resisitivity	Apparent water resistivity for each zone, based on the Archie parameters and the zone porosity (PHI) and resistivity (RT) values.
RO	Resistivity of Water Saturated Zone	The resistivity of each zone if it was completely saturated with formation water whose resistivity matched the value recorded in cell Archie parameter RW and a rock with Archie parameters A and M.
MA	Apparent Archie cementation exponent	Apparent Archie cementation exponent is calculated under the assumption that the zone is completely water-saturated and that the Archie parameter value RW is the actual formation water resistivity. This computation is a companion technique to the RWA method, but in this case provides a means to estimate the cementation exponent in water zones where formation water resistivity is known, but the Archie equation parameters are poorly known. The values of MA also represent the slopes of an individual water line that result when the zone is located on the Pickett plot and linked with the formation water resistivity intercept.
SW	Proportional water saturation	The calculated values of proportional water saturation, using the zone porosity (PHI) and resistivity (RT) value in conjunction with the Archie equation values of a, m, n and Rw
BVW	Fractional bulk volume water	Calculation of the fractional bulk volume water in each zone as the product of the fractional porosity and water saturation. As described earlier in this manual, the BVW is often known as the "Buckles number" in reservoir zones at "irreducible" water saturation. The value is controlled primarily by pore size, where large pores cause low Buckles numbers, and small pores are matched by high Buckles numbers.
VSH	Fractional proportion of shale	The formula for the VSH column may be set automatically using the Vsh button on the PfEFFER toolbar
PAY	Incremental thickness of oil (or gas)	incremental thickness of oil (or gas) in each zone, given by THK*PHI*(1-SW), assuming that the zone satisfies a number of criteria, described below. If a particular zone does not satisfy those criteria, then the PAY entry for that zone is 0, meaning that the zone does not contribute to the net thickness of oil computed in FTOIL
1st PHI	Primary porosity	The primary porosity is determined from the interpolation of the observed bulk transit time between the matrix and fluid transit time extremes, as shown by the formula above. The total porosity column is set equal to column PHI, the porosity in the home area.
2nd PHI	Secondary porosity	Secondary porosity is the total porosity (column PHI) minus the primary porosity determined from the sonic log.
PHIr	"Electrically connected porosity"	PHIr (connected porosity) is estimated from resistivity log as the square root of Reconnaissance (apparent) water resisitivity (RWA) divided by the Resistivity of Water Saturation Zone (RO).
RXO	Bulk resistivity of flushed zone	Choice of resistivity log to be used is at the discretion of the user.
SXO	Saturation of total moveable fluid (assumes filtrate has displaced everything moveable)	The calculated values of saturation of total moveable fluid, using the zone porosity (PHI) and bulk resistivity of flushed zone (Rxo) value in conjunction with the Archie equation values of a, m, n and Rmf
BVF	Bulk volume fluid	Calculation of the fractional bulk volume water in each zone as the product of the fractional porosity and saturation of total moveable fluid. Computed as the product of Sxo and PHI.

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Next Section Cut-Offs and Colors

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REFERENCE:
Pfeffer Version 2.0/Pro (Petrofacies Evaluation of Formations for Engineering Reservoirs) Manual, PfEFFER File Organization, Pages 71-76