Oil Formation Volume Factor (Bo)
Compute the oil formation volume factor (Bo) by dividing the volume the oil occupies at reservoir conditions by the volume it occupies at the surface (stock-tank barrels). Bo is always greater than 1 because, in the reservoir, the oil is hot and has dissolved gas, occupying more space; as it rises and loses gas and heat, it shrinks. It is essential to convert reservoir volumes into surface production. Enter the volumes at reservoir and surface conditions.
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Fator volume de formação do óleo (Bo)
Um barril de óleo medido lá no fundo do reservatório não dá um barril na superfície — dá menos. O fator volume de formação Bo = volume no reservatório / volume na superfície captura esse encolhimento, e é sempre maior que 1 (tipicamente 1,1 a 1,8). Por quê? No reservatório, o óleo está quente (dezenas a centenas de graus) e, crucialmente, com muito gás dissolvido sob alta pressão — como um refrigerante lacrado. Ao subir pelo poço e passar pelos separadores, ele esfria e libera o gás (que vira produção de gás separada), encolhendo o líquido que resta. O Bo é medido em laboratório por análise PVT (pressão-volume-temperatura) de amostras do fluido, e varia com a pressão (cresce até o ponto de bolha, depois cai). É indispensável para converter volumes de reservatório em barris de tanque vendáveis — aparece no cálculo do OOIP e no balanço de materiais. Informe os volumes em condições de reservatório e de superfície.
Related Tools
Recoverable Oil Reserves
Compute the recoverable oil reserves by multiplying the original oil in place (OOIP) by the recovery factor (%). While the OOIP is the total volume present in the rock, only a fraction is technically and economically extractable — those are the reserves that actually have value and enter oil companies' books. It is the number behind asset valuations and investment decisions. Enter the OOIP and the recovery factor.
Reservoir Recovery Factor
Compute a reservoir's recovery factor, RF = (Np/N)·100%, the fraction of the original oil (N, or OOIP) that will actually be produced (Np). It is one of the most important — and uncertain — numbers in the industry: primary recovery (natural energy) is usually 5–15%; with secondary recovery (water/gas injection) it rises to 30–50%; and advanced methods (EOR) can go further. It defines the field's economic value. Enter the cumulative production and the original oil in place.
Oil in Place (OOIP)
Compute a reservoir's original oil in place (OOIP) by the volumetric method, OOIP = 7758·A·h·φ·(1−Sw)/Boi, in stock-tank barrels (STB). It combines the reservoir area (acres), the porous thickness (ft), the porosity (φ), the water saturation (Sw) and the oil formation volume factor (Boi). The constant 7758 converts acre-feet into barrels. It is the basis of any oil-field evaluation. Enter the area, thickness, porosity, water saturation and Boi.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.