...
and
- wellbore fluid deliverability (the ability of well to lift up or lift down the fluid) and which is called OPR or TPR or VFP (equally popular throughout the literaturecalled Vertical Flow Performance (VFP) or Tubing Performance Relation (TPR)
It is based on correlation between surface flowrate
and bottomhole pressure
as a function of tubing-head pressure
and formation pressure
and current reservoir saturation.
...
- Inflow Performance Relation (IPR) – responsible for reservoir deliverability (see below)
...
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| Fig. 2. A sample case of stablised flow rate as function of formation pressure. | Fig. 3. A sample case of stablised flow rate as function of formation water saturation and corresponding production water-cut.
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| Fig. 4. A bunch of IPRs IPRs at different formation pressures and TPRs VLPs at different THPs THPs. |
Workflow
...
- Check the current production rate against the production target from FDP
- If the diffference is big enough to justify the cost of production optimization (see point 8 below) then proceed to the step 3 below
- Assess formation pressure based on well tests
- Simulate IPR/OPR VFP based on the current WOR/GOR
- Calculate the stabilized flow bottom-hole pressure
- Gather the current bottom-hole pressure
- Check up the calculation aganst the actual
- Recommend the production optimisation activities to adjust bottom-hole pressure :
- adjusting the choke at surface
- adjusting the pump settings from surface
- changing the pump depth
- changing the tubing size
- changing the pump
...
