M/s. Indian Oil Corporation Ltd. (IOCL) has entrusted iFluids Engineering to conduct the Hazard and Operability Study (HAZOP) for the Digboi Refinery in Assam in line with OISD guideline. The scope of the project is to conduct HAZOP study of all the process units and utility & offsite facilities in the complex of Digboi Refinery. Digboi Refinery has a crude processing capacity of 0.65 MMTPA. It processes waxy crude extracted from oil fields operating in an area near Digboi.
HAZOP Study
The objective of the HAZOP study was to identify hazard and operability problems and to reduce the probability and consequences of an incident in the process units and utility & offsite facilities in the Indian Oil Corporation Ltd. (IOCL) that would have a detrimental impact to the personnel, plant, properties and environment.
Methodology of HAZOP
- Node Marking based on (Stream, equipment or a Package) on the P&ID
- List the intention & process parameters, guidewords for the node
- List all deviations and ignore deviations that are not meaningful and Apply the deviation
- Brainstorm and list various causes of the deviation and ignore causes that are not credible
- Determine the consequences of the deviation due to each listed credible cause
- Identify Safeguards already provided in the system
- Identify Risk Matrix based on severity & likelihood
- Suggest recommendations/actions, should the safeguards be inadequate
HAZOP Study of Process Units at Digboi Refinery.
| S.No. | Process Unit | No. of P&ID |
| 1 | CPP | 34 |
| 2 | AVU-CDU-VDU | 56 |
| 3 | CRU | 23 |
| 4 | DCU | 47 |
| 5 | HDT | 105 |
| 6 | HGU | 45 |
| 7 | SDU | 84 |
| 8 | SRU | 27 |
| 9 | SWS | 5 |
| 10 | DM PLANT | 2 |
| 11 | HDT offsite HPNU | 8 |
| 12 | LDU | 1 |
| 13 | MSQ | 53 |
| 14 | NTF | 7 |
| 15 | WHF | 20 |
| 16 | WPU | 4 |
Project Duration: 04 Months
Software Used: The HAZOP software used was PHA-Pro/PHA