Basic of Water Flooding

Basic of  waterflooding By :Nsingi Mvuka Antonio June 2010

What is waterflooding? Watermflooding is the use of injection water to priduce oil

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Factor Affecting waterflooding

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Reservoir characteristics •

Depth

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Structure

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Homogeneity

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Petrophical properties (porosity, saturation and avarage permeability)

Fluid characteristics •

Viscosity •

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Mobility ratio

Location of injection and producers The injention and production wells should be placed to accomplish the flollowing: Provide the desire oil productivity and the necessary water injection rate to yield this oil productivity. •

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Take advantage of reservoir characteristics.

In general 2 kinds of flooding patterns are used: •

Peritheral flooding

Patterns flooding

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Location of injection and producers In general two kinds of flooding patterns are used: •

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Peripheral flooding

Patterns flooding

Peripheral flooding

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Patterns flooding

Optimum Time to Waterflooding The most common procedure for determining the optimum time to start waterflooding is to calculate: • Anticipated oil recovery

• Fluid production rates • Monetary investment • Availability and quality of the water supply • Costs of water treatment and pumping equipment • Costs of maintenance and operation of the water installation facilities • Costs of drilling new injection wells or converting existing production wells into injectors

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Optimum Time to Waterflooding Optimum time for waterflooding or secondary recovery

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Estimation of waterflooding recovery efficiency

The overall recovery factor (efficiency) RF of any secondary or tertiary oil recovery method is the product of a combination of  three individual efficiency factors as given by the following generalized expression:

In terms of cumulative oil production, Equation 14-5 can be written as:

where RF = overall recovery factor NS = initial oil in place at the start of the flood, STB NP = cumulative oil produced, STB ED = displacement efficiency EA = areal sweep efficiency EV = vertical sweep efficiency 8