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Natural Depletion
Oil Depletion
The EUR during the natural oil depletion can be assessed with the following formula:
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where
– tubing-head pressure defined by the production gathering system,
– is the true vertical depth at formation top,
| LaTeX Math Inline |
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| body | \{ \rho_o, \, \rho_g \} |
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– oil and gas densities,
– bubble-point pressure.
Gas Depletion
The Expected Ultimate Recovery during the natural gas depletion can be assessed with the following formula:
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| LaTeX Math Block |
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EUR_{GD} = \frac{Q_g}{V_g} = 1- \frac{p_{wf}}{p_i} |
Water flooding
Motivation = maintain formation pressure at sweep interface
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where
–
displacement efficiency,
–
sweep efficiency.
Sweep efficiency
| Excerpt Include |
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| SFLSHR:Sweep Efficiency |
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| SFLSHR:Sweep Efficiency |
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| nopanel | true |
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Water-Oil displacement efficiency
| Excerpt Include |
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| SFLSHR:Water-Oil Displacement Efficiency |
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| SFLSHR:Water-Oil Displacement Efficiency |
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| nopanel | true |
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Gas flooding
Motivation = maintain formation pressure at sweep interface with gas in case of high water mobility
| LaTeX Math Inline |
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| body | \frac{k_{rw}}{\mu_w} \gg \frac{k_{ro}}{\mu_o} |
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which makes waterflood inefficient.
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| Excerpt Include |
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| SFLSHR:Gas-Oil Displacement Efficiency |
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| SFLSHR:Gas-Oil Displacement Efficiency |
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| nopanel | true |
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WAG flooding
Motivation = maintain formation pressure at sweep interface with alternating inejction of water and gas in case of high residual oil to water sweep is high
and gas sweep is less than to water sweep
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| LaTeX Math Block |
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E_D = \frac{1-s_{wi}-s_{org}}{1-s_{wi}} |
Chemical EOR
Motivation = maintain formation pressure at sweep interface with chemical injection and reduce residual oil to EOR sweep
| LaTeX Math Inline |
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| body | s_{or \, eor} < s_{orw} |
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.
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where
– inititial water in oil pay,
– residual oil to injection sweep.
CО2 injection
Reference
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[1]
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