Concepts and Equations for Petroleum Engineers

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Юкос, 2003. — 47 с.Методическое пособие по нефтегазовому делу для инженеров. Собраны и систематизированы по подразделам все формулы и графики, с которыми приходится сталкиваться разработчику. Даны все необходимые пояснения и единицы измерения Reservoir EngineeringDarcy’S law Expressio Darcy’s law in field metric units Darcy’s law in radial steady-state flow Darcy’s law in radial flow pseudosteady-state flowOoip/Reserves Ooip- Original Oil in Place ReservesSkin factor Definition The additional pressure drop due to skin effect, ∆ps ExampleDiffusivity equation, Flow regimes Diffusivity equation in radial form Semi steady state (or pseudo steady-state) Steady stateWell test analysis Pressure Drawdown or Injectivity Buildup or FalloffWater injection compensation immiscible displacement (Waterflooding) Linear water fractional flow equation, fw Average water saturationMaterial balance methods General equation Fe method (solution gas drive) Gascap method Havlena – Odeh Method Campbell Method Pressure match methods (any reservoir) Production EngineeringBottom hole Pressure (Bhp) In esp pump wells Vertical well case Deviated wells (subtract a constant correction) Units conversionOil flow rate based on total liquid and water cut Volumetric flowrate Mass flowrate Example Units conversionProductivity index pi Definition Pi for steady state flow to a vertical well Pi for pseudosteady – state flow to a vertical well Pi calculation given qL, pwf and pRInflow performance relationship (Ipr) Vogel model in dimensionless form General Ipr based on Vogel’s model General Ipr based on Fetkovich’s model Example problem (Ipr)Flow efficiency definition Fe for steady-state flow Fe for pseudosteady-state flowCalculations for enhancement candidate selection Enhancement Calculation of potential oil rate incrementCalculations for fracturing well candidate selection Calculation of potential oil rate increment Esp pump designFracture efficiency definitionFracture design equations Rock mechanics parameters Fluid volume pumped (Vi) Fracture volume (Vf) Volume lost into the reservoir (Vlp) Fracture half length or penetration (l) dimensionless fracture conductivity (Fcd)Md, Tvd and tvdss single phase pressure Drop in casing or tubing pressure drop in casing or tubing pressure drop in annularFlow through chokes Gilbert equation (water/oil, producing gas) Example poettmann and Beck’s chartsMultiphase prEssure drop in casing or tubing General pressure drop expression Orkiszewski’s correlation Bubble flow Slug flow Continuous oil phase Continuous water phaseOil pvt properties Oil specific gravity and Api gravity Bubble pressure or saturation pressure Dead oil viscosity Oil viscosity above bubble point pressure Oil formation volume factor (Standing)Gas properties Real gas equation of state (Eos) Gas Fvf gas viscosityDecline curve equations General mathematical expression Exponential or constant decline Hyperbolic decline Harmonic decline Formation EvaluationShale volume by gr and sp Definition: shale content, Vsh Gr – natural gammy ray log Sp – spontaneous potentialPorosIty from porOsity logs Porosity of clean reservoirs (Vsh=0) Porosity of shaly reservoirs, shale content correctionArchie’S equations Formation factor Formation resistivity index, I Example Correction for shale content (Vsh) Example