Difference between revisions of "Oil Flowing Material Balance"
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:<math> P_{po} </math> = oil pseudo pressure, psia | :<math> P_{po} </math> = oil pseudo pressure, psia | ||
:<math> P_{ref} </math> = reference pressure, psia | :<math> P_{ref} </math> = reference pressure, psia | ||
| − | :<math> P_{wf} </math> = well | + | :<math> P_{wf} </math> = well flowing pressure, psia |
:<math> q_o </math> = oil rate, stb | :<math> q_o </math> = oil rate, stb | ||
Revision as of 07:52, 10 April 2018
Contents
Brief
Oil Flowing Material Balance (Oil FMB) is the advanced engineering technique published in 2005 by Louis Mattar and David Anderson [1].
Oil Flowing Material Balance is applied to determine:
- Reservoirs STOIIP & EUR
- Well's EUR and JD
Oil Flowing Material Balance uses readily available Well flowing data: production rate and bottomhole pressure.
The interpretation technique is fitting the data points with the straight lines to estimate STOIIP and JD.
Math & Physics
The total pressure drop at the wellbore is:
Where
, is pressure drop due to depletion defined by the Oil Material Balance
, is pressure drop due to Darcy's law
In terms of oil pseudo pressure the total pressure drop is:
Where
Finally, the Oil Flowing Material Balance equation:
Or
Where
Discussion
Oil Flowing Material Balance can be applied to:
- single well
- multiple wells producing from the same Reservoir.
The X axis on the Oil Flowing Material Balance Plot can be selected as:
Note what Oil Flowing Material Balance accounts for the changing PVT properties of the oil.
Example 1. Multiple wells producing from the same Reservoir. X axis - Wells cumulative
Example 2. Multiple wells producing from the same Reservoir. X axis - Reservoir cumulative
Example 3. Shifted Model Start (to account for gas injection)
Workflow
- Upload the data required
- Open the Oil Flowing Material Balance tool here
- Estimate the N (red line X-axis intercept)
- Calculate the average reservoir pressure
based on N, known production data and using Oil Material Balance equation - Calculate the
- Calculate the
- Plot the orange vs line:
- Change the N to match the orange line with the red one
- Change the gray JD line Y-axis intercept to match the changing JD
- Save the Oil Flowing Material Balance model
- Move to the next well
Data required
- Create Field here
- Create or Upload Reservoirs here
- Input the Reservoirs GIIP and STOIIP here
- Create or Upload PVT (SG, Pi, Ti) here
- Upload Wells
- Create or Upload Wells Perforations here
- Create or Upload kh and JD here
- Upload Daily Measures
In case you need to calculate the flowing bottomhole pressure from the wellhead pressure:
- Calculate the flowing bottomhole pressures using BHP Calculator
- Export flowing bottomhole pressures to Daily Measures here
In case you want to add the static reservoir pressures on the FMB Plot:
- Create or Upload the static reservoir pressures, here
- Calculate Monthly Measures from the Daily Measures using Monthly Data Calculator
Nomenclature
= oil formation volume factor as a function of pressure, bbl/stb
= dimensionless productivity index, dimensionless- = dimensionless productivity index in terms of the oil pseudo pressure, dimensionless
= permeability times thickness, md*ft
= stock tank oil initially in place, stb- = normalized cumulative oil production, stb
= pressure, psia- = average reservoir pressure, psia
= initial pressure, psia
= oil pseudo pressure, psia
= reference pressure, psia
= well flowing pressure, psia
= oil rate, stb
Greek symbols
= oil viscosity as a function of pressure, cp
References
- ↑ 1.0 1.1 Mattar, L.; Anderson, D (2005). "Dynamic Material Balance (Oil or Gas-In-Place Without Shut-Ins)" (PDF). CIPC.
- ↑ 2.0 2.1 Stalgorova, Louis; Mattar, Ekaterina (2016). "Analytical Methods for Single-Phase Oil Flow: Accounting for Changing Liquid and Rock Properties". Society of Petroleum Engineers.
