Section 5 - Typical Oil Pumping And metering Systems

Question 1

What safety features would you expect to see on the suction side of the booster pumps?

Answer 1

As ESDV interlock from the platform ESD system, triggered by fire conditions or low level within the 2nd Stage Separator. There is also an upstream block valve with a limit switch for the purpose of electronic interlock.

Question 2

What prevents debris from entering the suction side of the booster pump?

Answer 2

A T-Filer is usually in place. Monitored by a PDS.

Question 3

What follows the filter in the Booster pump system?

Answer 3

The Booster pump set, which also has Pressure switch high and low protection.

Question 4

What follows the Booster pump in the booster pump set and what is its function?

Answer 4

The minimum flow non-return valve, which sends Oil back to the 2nd stage separator through a Hand valve with interlock.

Question 5

What follows the minimum flow return valve in a booster pump loop?

Answer 5

The Downstream check valve, the common header inlet and the LCV arrangement (including maintenance valves).

Question 6

Where does the LCV receive its level control signal from?

Answer 6

The 2nd Stage separator.

Question 7

What 4 Types of system form the Sampling system?

Answer 7

The Sampling system (with central bypass).
The Sampling pumps.
The Densitometers.
The Base Water and Sediment system.

Question 8

In a Sampling system, what is the first section of the loop focused on?

Answer 8

The first section of the loop is the sampling system, which can be bypassed.

Question 9

What follows the sampling system in a sampling loop?

Answer 9

The sampling pumps follow the sampling system in the sampling loop.

Question 10

What follows the sampling pumps in the sampling loop?

Answer 10

The BS&W meter is in series and the Densitometer loop is in parallel. There are two DTs and only one BS&W system.

Question 11

From the booster pumps, what occurs prior to the first block valve in a metering system?

Answer 11

The sampling take off and return occurs, and the common header to the other metering runs is present.

Question 12

What follows the first Block valve in a metering system?

Answer 12

The filter, which is monitored by a PDS, and which protects the straightening vanes. There is also a PSV which lifts should upstream blockage of the meter or vanes occur.

Question 13

What follows the vanes in a metering system?

Answer 13

The flow element, either the turbine or DP meter. This feeds the flow rate to the flow computer.

Question 14

What happens after the oil is metered in a metering system?

Answer 14

Oil branches off, passing through an FCV and MoV which is controlled by the flow computer.

Question 15

What happens when the meter is on prove?

Answer 15

The MOV linking the flow meter to the main pipeline pumps closes, and diverts oil through the prover loop MOV, the prover loop and the prover FCV.

Question 16

What are the key differences between the Booster pump loop and the Main Oil Pump loop?

Answer 16

The minimum Flow Recycle line goes through a sea water cooler. There is no filter before the pump, and only an ESDV on the outlet.

Pump speed is controlled by a fluid coupling controlled by pipeline pressure feedback.

Question 17

Why isn’t oil simply recycled to the 2nd stage separator when in minimum flow on the main oil export system?

Answer 17

This would introduce duplicated metering and induce erroneous flow measurement.

Question 18

How does the Main Oil pump control its outlet speed and pressure?

Answer 18

Through a variable speed drive, which is a fluid coupling linked to the pipeline pressure controller.

Pipeline Pressure low, increases pump speed.
Pipeline Pressure High, reduces pump speed.

Question 19

What is a fluid coupling?

Answer 19

A fluid coupling, or a hydraulic coupling, is a coupling which relies on transfer of power from an oil circulating pump, through a runner (pump), which drives oil against the impeller of the outer shaft. This shaft drives the main oil pump.

Question 20

Where does oil flow from to the Booster system?

Answer 20

The 2nd Stage Oil Seperator

Question 21

What is the function of a Scoop tube?

Answer 21

A scoop tube controls the volume of Oil in the scoop chamber. When at full extension it removes all oil, removing any mechanism for hydraulic coupling. At minimum extension it allows full load of transfer from the AC Motor through the fluid coupling.