Business Functions Library for Excel

    1. Introduction
      1. Introduction
      2. DYear
      3. DMonth
      4. DateYMD
      5. DateSeqNum
      6. IsSeqDate
      7. DayName
      8. MonthName
      9. IsLeap
      10. DaysInMonth
      11. IsAnniversary
      12. WeekNumber
      13. WeekNumberToDate
      14. MonthStart
      15. MonthEnd
      16. NumPers
      17. MostRecent
      18. MostImminent
      19. TimeBaseLengths
      20. AnnSeq
      21. CreateTimeBase
      1. Introduction
      2. DiffY
      3. DiffM
      4. DiffD
      5. DiffP
      1. Introduction
      2. DpY
      3. DpM
      4. DpD
      5. DpP
      6. PrevDateSeq
      7. NextDateSeq
      8. PrevDateList
      9. NextDateList
      10. NextDateCombine
      11. DatePer
      12. EDateBF
      13. DateSeq
      14. DateSeqCombine
      1. Introduction
      2. TpY
      3. TpM
      4. TpD
      5. Occurs
    1. Introduction
      1. Introduction
      2. DpYBD
      3. DpMBD
      4. DpDBD
      5. NextBD
      6. PrevBD
      7. NextDateSeqBD
      8. PrevDateSeqBD
      9. IsBD
      10. NetWorkDaysBF
      11. NextDateListBD
      12. PrevDateListBD
      1. Introduction
      2. Holiday
      3. DescribeHol
      4. WhatHol
      5. IsHol
      6. IsWE
      7. WesternEaster
      8. CreateDate
    1. Introduction
      1. Introduction
      2. MkPmtsSeq
      3. MkPmts
      4. MkPmtsGrow
      5. MkPmtsFcst
      6. MkPmtsSF
      7. MkPmtsLim
      8. MkPmtsLag
      9. MkPmtsLagProf
      10. RePhasePmts
      11. TotPmts
      12. TotPmtsSF
      13. SumBetween
      14. DoBetween
      15. MatchPmts
      16. CarryNeg
      17. CarryPos
      18. MkPmtsX
      19. MkPmtsLagX
      20. MkPmtsIdx
      21. MkPmtsCats
      22. MkPmtsGroup
      1. Introduction
      2. MkPmtsPer
      3. MkPmtsPerGrow
      4. MkPmtsPerFcst
      5. MkPmtsIdxPer
      1. Introduction
      2. MkPmtsGrowMkt
      3. MkPmtsFcstMkt
      4. MkPmtsPerGrowMkt
      5. MkPmtsPerFcstMkt
    1. Introduction
      1. Introduction
      2. GSpread
      3. UniSpread
      4. UniSpreadGrow
      5. SCurve
      6. SCurveGrow
      7. DistSpread
      8. FStepSpread
      9. TStepSpread
      10. MkPmtsWeighted
      11. SCumCurve
      1. Introduction
      2. UniSpreadPer
      3. SCurvePer
      4. SCurveGrowPer
      5. UniSpreadGrowPer
      1. Introduction
      2. WeightSpread
      3. FWeightSpread
      4. TWeightSpread
      1. Introduction
      2. UniSpreadH
      3. SCurveH
      4. WeightSpreadH
      5. FWeightSpreadH
      6. TWeightSpreadH
      7. DistSpreadH
      8. GSpreadH
      9. UniSpreadAdj
      10. SCurveAdj
      11. WeightSpreadAdj
      12. FWeightSpreadAdj
      13. TWeightSpreadAdj
      14. DistSpreadAdj
      15. GSpreadAdj
    1. Introduction
      1. Introduction
      2. Con
      3. ConGrow
      4. AnnGrow
      5. RePhaseCon
      6. AnnRate
      7. ConSF
      8. ConIdx
      9. ConEvent
      1. Introduction
      2. ConPer
      3. AnnGrowPer
      4. ConGrowPer
      1. Introduction
      2. ConGrowMkt
      3. ConFcstMkt
      4. ConFcstGrowMkt
      1. Introduction
      2. ConRevGrow2
      3. ConRev
      4. ConRevGrow
      5. ConRevFcst
    1. Introduction
      1. Introduction
      2. FStep
      3. FStepGrow
      4. FStepGrowX
      5. FStepThenGrow
      6. FStepFcst
      7. FStepGrown
      8. FStepSF
      9. FStepCombine
      10. MultiFStep
      1. Introduction
      2. TStep
      3. TStepGrow
      4. TStepGrowX
      5. TStepThenGrow
      6. TStepFcst
      7. TStepGrown
      8. TStepSF
      9. TStepCombine
      10. MultiTStep
      1. Introduction
      2. FStepGrowMkt
      3. FStepFcstMkt
      4. TStepGrowMkt
      5. TStepFcstMkt
      1. Introduction
      2. FStepRev
      3. TStepRev
      4. FStepRevGrow
      5. FStepRevFcst
      6. TStepRevGrow
      7. TStepRevFcst
      8. FStepThenGrowRev
      9. TStepThenGrowRev
    1. Introduction
      1. Introduction
      2. FittedRate
      3. Ramp
      1. Introduction
      2. InterpedLevel
      3. FittedLevel
    1. Introduction
      1. Introduction
      2. Bal
      3. Level
      4. FLevels
      5. TLevels
      6. FLevelsGrow
      7. TLevelsGrow
      8. FLevelsFcst
      9. TLevelsFcst
      10. FLevelsCombine
      11. FLevelsThenGrow
      12. TLevelsThenGrow
      1. Introduction
      2. FLevelsGrowMkt
      3. TLevelsGrowMkt
      4. FLevelsFcstMkt
      5. TLevelsFcstMkt
      1. Introduction
      2. Grow
      3. GrowFromTo
      4. FGrowStep
      5. TGrowStep
      6. FGrowStepMkt
      7. TGrowStepMkt
      8. GrowMkt
      9. GrowLin
      1. Introduction
      2. Fcst
      3. FcstGrow
      4. FcstCollar
      5. SumFcst
      6. FFcstStep
      7. TFcstStep
      8. IdxFromTo
      1. Introduction
      2. FcstT
      3. TFcstT
    1. Introduction
      1. Introduction
      2. ALevel
      3. FALevels
      4. TALevels
      5. FALevelsGrow
      6. TALevelsGrow
      7. FALevelsFcst
      8. TALevelsFcst
      9. FALevelsThenGrow
      10. TALevelsThenGrow
      11. ALevelGrow
      1. Introduction
      2. FALevelsGrowMkt
      3. TALevelsGrowMkt
      4. FALevelsFcstMkt
      5. TALevelsFcstMkt
      1. Introduction
      2. AGrow
    1. Introduction
      1. Introduction
      2. PVCon
      3. PVAnnGrow
      4. PVConGrow
      5. PVConQ
      1. Introduction
      2. PVTStep
      3. PVTStepQ
      4. PVTStepIC
      5. PVTStepICQ
      6. PVFStep
      7. PVFStepIC
      8. PVFStepQ
      9. PVFStepICQ
      1. Introduction
      2. PVMkPmtsSF
      3. PVMkPmts
      1. Introduction
      2. PVGSpread
      3. PVUniSpread
      4. PVSCurve
      5. PVSCurveGrow
      6. PVDistSpread
      7. PVFStepSpread
      8. PVTStepSpread
      9. PVMkPmtsWeighted
      10. PVSCumCurve
    1. Introduction
      1. Introduction
      2. SimpleToSimple
      3. SimpleToAER
      4. SimpleToCont
      5. SimpleToDF
      6. AERToSimple
      7. AERToCont
      8. AERToDF
      9. ContToSimple
      10. ContToAER
      11. ContToDF
      12. DFToSimple
      13. DFToAER
      14. DFToCont
      1. Introduction
      2. SimpleToSimpleX
      3. SimpleToAERX
      4. SimpleToContX
      5. SimpleToDFX
      6. AERToSimpleX
      7. ContToSimpleX
      8. DFToSimpleX
      9. RateConvert
      1. Introduction
      2. FVM
      3. PVM
      4. PmtM
      5. TermM
      6. IntRateM
      7. PVEGAnn
      8. PVEGAnnM
      9. PVEGPerAnn
      10. PVEGPerp
      11. PVEGPerpM
      12. PVEGPerPerp
      13. SumEGAnn
      14. SumEGAnnM
      15. SumEGAnnCont
      16. SumLGAnn
      17. SumLGAnnM
      18. SumLGAnnCont
      1. Introduction
      2. PVBF
      3. PMTBF
      4. RateBF
      1. Introduction
      2. APRToQuoted
      3. QuotedToAPR
    1. Introduction
      1. Introduction
      2. PVOne
      3. FPVOne
      4. TPVOne
      5. PVOneQ
      1. Introduction
      2. PVA
      3. IRRA
      4. PayBackA
      5. PayBackDiscA
      6. DurationA
      7. AvLifeA
      1. Introduction
      2. PVE
      3. IRRE
      4. PaybackE
      5. PayBackDiscE
      6. DurationE
      7. AvLifeE
      1. Introduction
      2. PVT
      3. IRRT
      4. PayBackT
      5. PayBackDiscT
      6. DurationT
      7. AvLifeT
      8. PVTIC
      9. IRRTIC
      10. PVTX
      11. IRRTX
      12. PVTCX
      13. IRRTCX
      14. PVTR
      15. IRRTR
      1. Introduction
      2. NPVM
      3. IRRM
      4. CorrectionM
      5. CorrectionCont
      6. CorrectionDC
      7. DurationM
      8. AvLifeM
      9. EffTimeM
    1. Introduction
      1. Introduction
      2. Depreciate
      3. DepreciatedValue
      4. DepPoolWIP
      5. DepPoolRatio
      6. DepPool
      7. DepreciatePer
      8. DepreciateGrowPer
      9. DepreciateFcstPer
      10. DepreciateIdxPer
      11. LIFOPrice
      12. LIFOCalc
      1. Introduction
      2. FAvRate
      3. TAvRate
      4. FAvRateTD
      5. TAvRateTD
    1. Introduction
      1. Introduction
      2. LinReg
      3. BestPoly
      4. SignChanges
      5. RSqrdPoly
      6. PolyEqn
      7. CalcPoly
      8. PolyReg
    1. Introduction
      1. Introduction
      2. LookupNum
      3. LookupN
      4. SeekNum
      5. PickNum
      6. SortPick
      7. LookUpNum2D
      8. PickMatrix
      9. LookupNIndex
      10. Seek
      11. SeekList
      12. SortNum
      13. FindIf
      1. Introduction
      2. DoBetweenX
      3. SumCat
      4. SumCats
      5. SumPos
      6. SumNeg
      7. SumDiv
      8. SumBounds
      9. SumSubRange
      10. SumCombine
      11. SelCats
      1. Introduction
      2. Coordinates
      3. WorkSheetName
      4. RefPlus
      5. GetRef
      1. Introduction
      2. MinBetween
      3. MaxBetween
      4. MeanNZ
      5. WeightAv
      1. Introduction
      2. RangeDir
      1. Introduction
      2. SortText
      3. ApplyToList
      4. CombineLists
      5. TransposeNum
      6. Unique
      1. Introduction
      2. Interp
      3. Interpolate
      4. InterpDate
      5. InterpolateDate
      6. Intersection
    1. Introduction
      1. Introduction
      2. Distribution
      3. PartialDependency
      4. DistCumulative
      5. DistUniform
      6. DistTriangular
      7. DistDoubleTri
      8. DistNormal
      9. DistLogNormal
      10. RandNum
      11. NRandom
      12. PickRandom
      13. DescribeDistType
      14. CumProb
    1. Introduction
      1. Introduction
      2. RentGrow
      3. RentFcst
      1. Introduction
      2. FStepRent
      3. FStepRentGrow
      4. FStepRentFcst
      5. FStepRentFcstCollar
      1. Introduction
      2. TStepRent
      3. TStepRentGrow
      4. TStepRentFcst
      5. TStepRentGrowCollar
      6. TStepRentFcstCollar
      1. Introduction
      2. RentFcstR
      3. RentGrowR
      4. FStepRentGrowR
      5. FStepRentFcstR
      6. TStepRentGrowR
      7. TStepRentFcstR
      8. TStepRentGrowSFR
      9. FStepRentGrowSFR
      10. TStepRentFcstSFR
      11. FStepRentFcstSFR
      1. Introduction
      2. CapValue
      3. EqYield
      4. CapValueG
      5. EqYieldG
      6. CapValueGD
      7. EqYieldGD
      8. NomToTrue
      9. TrueToNom
      10. YPP
      11. YPPDef
      12. YPA
      13. YPADef
      14. CapValueGrowGD
      15. CapValueFcstGD
      16. EqYieldGrowGD
      17. EqYieldFcstGD
      1. Introduction
      2. CapValueDCF
      3. EqYieldDCF
      4. CapValueDCFG
      5. EqYieldDCFG
      6. CapValueDCFGD
      7. EqYieldDCFGD
      8. NomToTrueDCF
      9. TrueToNomDCF
      10. YPADefDCF
      11. YPPDefDCF
      12. TheorYield
      13. ImpGrowth
      14. ImpDiscRate
      15. PVRent
      16. TWRR
      1. Introduction
      2. PVRentGrow
      3. PVRentFcst
      4. PVTStepRent
      5. PVTStepRentGrow
      6. PVTStepRentFcst
      7. PVTStepRentGrowR
      8. PVTStepRentFcstR
      9. PVTStepRentGrowIC
      10. PVTStepRentGrowRIC
      11. PVTStepIdxRentGrowR
      12. PVTStepIdxRentFcstR
      1. Introduction
      2. TStepGTurnRentGrow
      3. TStepGTurnRentGrowR
      1. Introduction
      2. IdxRentGrowR
      3. IdxRentFcstR
      4. IdxRentGrowMktR
      5. IdxRentFcstMktR
      6. TStepIdxRentGrowR
      7. TStepIdxRentFcstR
      1. Introduction
      2. LetCostR
      3. LetCostRQ
      4. LeasingFeeGrowR
      5. FServChargeR
      6. ServChargeGrowR
      7. ServChargeFcstR
      8. FServChargeGrowR
      9. FVacServChargeR
      10. VacServChargeGrowR
      11. VacServChargeFcstR
      12. LeasingFeeFcstR
      1. Introduction
      2. UKRatesGrow
      3. UKRatesFcst
      4. UKRatesGrowR
      5. UKRatesFcstR
      6. UKEmptyRatesFcstR
      7. UKEmptyRatesGrowR
      1. Introduction
      2. LeaseEnd
      3. ReletOccurs
      4. RentDateInfo
      5. RentEventOccurs
      6. RentEvent
      7. LastReview
      8. NextReview
      9. LastReviewR
      10. NextReviewR
      11. LeaseInfo
      12. Occupancy
      13. LeaseDates
    1. Introduction
      1. Introduction
      2. Interest
      3. FInterest
      4. TInterest
      5. TotInterestSF
      6. InterestX
      7. PVFInterest
      8. PVInterestX
      9. PVInterest
      1. Introduction
      2. ZeroCoupon
      3. FutureToSpot
      4. SpotToSpot
      1. Introduction
      2. Loan
      3. LoanX
      4. LoanLin
      5. LoanLinX
      6. Mortgage
      7. MortgageQ
      8. LoanPool
      9. MortgagePool
      10. IdxBondGrow
      11. IdxBondFcst
      1. Introduction
      2. Overdraft
      3. CashAcct
      4. FlexAcct
      5. CurrentAcct
      6. STDAcct
      7. LoanAcct
      8. LoanAcctEM
      1. Introduction
      2. BetaIndex
      3. BetaReturns
      4. DescribeReturn
      5. TotalReturn
      1. Introduction
      2. OptionBS
      3. OptionBinom
      4. OptionMonte
    1. Introduction
      1. Introduction
      2. STOIIP
      1. Introduction
      2. Decline
      3. DeclineRate
      4. DescribeDecline
      5. ProdProf
      6. AbandonDate
      7. StartDecline
    1. Introduction
      1. Introduction
      2. MoneyText
      1. Introduction
      2. GetToken
      3. GetTokens
      4. InString
      5. ExInt
      6. ExFl
      1. Introduction
      2. RegSMatch
      3. RegMatchWhole
      4. RegNMatches
      5. RegReplace
      6. RegSMatches
      7. RegSplit
    1. Introduction
      1. Introduction
      2. StdEq
      3. DiffGaps
      4. AddGaps
      1. Introduction
      2. SRound
      3. SFloor
      4. SCeiling
      5. RoundWeekDay
      6. RoundMonthDay
      7. RoundMD
      8. RoundDateSeq
      9. DateRound
      10. DateFloor
      11. DateCeiling
      12. Disperse
      13. RoundList
      1. Introduction
      2. BFVer
      3. DescribeLoanAcctOutput
      4. DescribeCombineSwitch
      5. DescribePmtsPerYear
      6. DescribeLevelSwitch
      7. DescribeBD
      8. DescribeDayCount
      9. DescribePeriods
      10. DescribeLookup
      11. DescribeRounding
      12. DescribeLoanOutput
      13. DescribeShape
      14. ArgValues
      1. Introduction
      2. Switch
      3. SwitchR
      4. SwitchT
      5. SwitchRT
      6. IfElse
      7. IfElseR
      8. IfElseT
      9. IfElseRT
      1. Introduction
      2. CollarDate
      3. InBetween
      4. Collar
      1. Introduction
      2. Ev
Decline Curve family
Production Profiling using Decline Curves
Description:
Introduction: This family uses Decline Curves to forecast oil and gas production, and can accommodate exponential, harmonic or hyperbolic decline.

The wide use of Decline Curves is based more on pragnatism than a strong theoretical case, because the pure drive mechanisms which the original equations were derived for rarely exist by themselves, and decline curves frequently "just happen to fit the data" rather than come from a strong analytical conviction.

The are main functions are:
  • Decline, that calculates either an instantaneous rate or cumulative production at a specific time (number of years) after the start of decline.
  • ProdProf which calculates a complete production profile by timeperiod. It can also output the instantaneous rate at the start or end of the period. The function accepts a production build-up too, prior to decline, via the AnnualRates variable.
These functions, through the ResvsOrDcRate variable, either accept a value for the produced Reserves figure (if the value is positive), or, if the value is negative, a value for the decline rate (known as a or ai). So ResvsOrDcRate=100 indicates reserves of 100 mmb, and ResvsOrDcRate=-0.1 indicates a decline rate of 10% per annum.
There are certain other "helper" functions:
  • AbandonDate is related to ProdProf, and it calculates the eventual abandonment date, to the nearest day (!). Like ProdProf, it accepts either a decline rate or a reserves figure.
  • StartDecline is also related to ProdProf, and it works out when the production reaches the DeclinePoint.
  • DeclineRate works out the decline rate given a plateau and abandonment rate.
  • DescribeDecline just outputs a text message describing the type of decline.

[What the family does not at present contain are any functions for fitting data to a decline curve. We are looking into exponetial curve-fitting functions - Feb"04]
Functions in the Decline Curve family (6)
  • Decline Production in decline up to, or at, a certain time
  • DeclineRate Calculate the Annual Decline Rate
  • DescribeDecline Describe in a text string the DeclineParam setting
  • ProdProf Generate an oil production profile based on pre-determined production rates and a decline curve
  • AbandonDate Calculate the Abandonment Date given an oil production profile based on pre-determined production rates and a decline curve
  • StartDecline Start of Decline Period

Business Functions phone: +44 (0)20 8144 9374 (London UK)
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