Engineering - Instrumentation And Control - BOP-ESD - Assessment Answer

Engineering Assignment

Assignment Task

TASK 1

Using candidate components listed above, provide a concept design for the BOP-ESD. Also, indicate and justify the fault tolerance levels used for the safety function.

For your design you can assume the following:

• There is sufficient space in the BOP to include at most one PLC and at most 2 DCVs.
• There is sufficient space in the BOP stack to include at most 1 additional Blind Shear Ram valve. If you decide the additional Blind Shear Ram valve is necessary, comment on and justify its preferred location within the BOP stack by considering common mode failures.
• There is sufficient electrical power and hydraulic power that can be obtained from existing BOP infrastructure to power all BOP-ESD components under normal operating conditions.
• All candidate components are classified as “Type A” or simple devices.
• The design should minimise component count but still meet all requirements.

Draw a RBD for the safety function of the BOP-ESD. Determine the PFD for the safety function and resulting SIL achieved. State the proof test interval required for the BOP-ESD components. All BOP-ESD components are to have identical proof test intervals. Use appendix B for relevant formulas.

Introduction

Using candidate components listed above, provide a concept design for the BOP-ESD. Also, indicate and justify the fault tolerance levels used for the safety function.

There is sufficient space in the BOP to include at most one PLC and at most 2 DCVs

This is the means by which the stepping stool graph searches for a basic begin/stop work. The capacity can be utilized to begin and quit anything like an engine begin/stop.

In this stepping stool rationale case, there are two information sources.

"Begin catch" or PLC input I0.0.

"Stop catch" or PLC input I0.1.

The begin catch will actuate the transfer, or step rationale hand-off M10.0. At the point when the begin catch is discharged, the transfer will at present be enacted, in view of the lock in stepping stool rung 2. This locking will be broken when the stop catch is initiated.

You may ask why the stop catch in this case is typically open. What's more, the explanation behind that, will be that you ought to utilize ordinarily shut as stop catch, to keep away from hazardous circumstances under disappointment.

On defer clocks in stepping stool rationale can look changed contingent upon the PLC programming. Be that as it may, basic for every one of them are the accompanying:

Input

Empower Output (EN)

Done Output (DN)

Preset Time Value

The empower yield (EN) is the principal yield and it is on when the clock is stimulated. In this way, the length of the info is valid or on, the empower yield will be valid.

Second yield is the done yield (DN). This yield in an on defer clock is just on, when the clock has checked down the preset time.

The control framework for the Deepwater Horizon victory preventer (BOP) upheld manual working of the BOP for typical boring operations and additionally programmed and physically started crisis capacities to seal the well. The totally programmed crisis close in capacities were the AMF/deadman and autoshear. The Crisis Disconnect System (EDS) was a manual shutdown framework, requiring human start. Each of these crisis close in frameworks were intended to initiate a crisis conclusion of the BOP by utilizing high weight pressure driven liquid to close the BOP dazzle shear slam (BSR), a gadget proposed to shear penetrate pipe going through the

BOP and afterward close in the well, halting any further stream of liquids from leaving the well. At different cases amid and taking after the victory of the Macondo well on April 20, 2010, each of these frameworks were called upon to seal the well.1 The principle center of this control framework examination has been on whether and when the AMF/deadman enacted. The control frameworks were looked into starting from the subsystem to a segment level, where adequate proof and testing were accessible for assessment.