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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.


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

HAZOP Study of Process Units at Digboi Refinery.

S.No.Process Unit   No. of P&ID
11HDT offsite HPNU8

Project Duration: 04 Months

Software Used: The HAZOP software used was PHA-Pro/PHA

Asian Paints Limited has an existing installation at Visakhapatnam district, Andhra Pradesh for the purpose of producing two main types of paint, namely industrial and decorative paints. While industrial paints are used for protection against corrosion and rust on steel structures, vehicles, white goods and appliances, decorative paints are used for protecting valuable assets like buildings.

Asian Paints Limited being keen on increasing the safety culture of the plant, has entrusted iFluids Engineering to perform the Hazard and Operability (HAZOP) study of the plant, located in Visakhapatnam, Andhra Pradesh.

A HAZOP study systematically reviews potential hazards and operability problems which could potentially lead to asset damage, business interruption, environmental damage, and/or personnel injury. The study helps identify problems or needs that the operator should consider and solve. It also helps classify the existing safeguards provided as prevention or mitigation. Recommendations and/or operating procedures are provided as prevention or mitigation measures against potential hazards and operability problems identified during HAZOP Study Workshop.

The HAZOP study was initiated with a Kick off meeting by a team of experts from iFluids Engineering along with the Asian Paints Limited multi-disciplinary team. The HAZOP study methodology and how the workshop would be performed was explained and the inputs required for the study were proposed. During the HAZOP Workshop, the multi-disciplinary team reviewed the relevant documents and discussed potential hazard and operability scenarios through a brainstorming session. The outcomes of the session were systematically recorded.

The recorded discussion were then reviewed by the experts of iFluids engineering and the report was produced to Asian Paints Limited. The methodology and results proposed by the iFluids team were accepted by Asian Paints for the identification and minimization of risk, which paved way for the successful completion of the project.

Bharat Petroleum Corporation Limited awarded iFluids Engineering to conduct the Hazard and operability study (HAZOP) for the following Process Plants: CDU/VDU3, DHDT, VGO HDT, PFCC, DCU, SRU3, NHT-ISOM and related Utilities.

HAZOP, the concise form of Hazard and Operability Study is a systematic way to identify the hazards associated in a process. Firstly, the study begins by breaking down the process into simple nodes and uses guidewords (No, Less, More) combined with the significant process parameters (Flow, Temperature, Pressure & Level) to form Deviations. Deviations helps us to brainstorm the causes for the particular deviation happens in the process. For Example: In a particular node, what are the causes for No flow. Then, it identifies the consequences and their safeguards present in the system for each cause. After that, it evaluates the sufficiency of the existing safeguards and access whether those safeguards are adequate enough to protect PEAR (People, Environment, Asset and Reputation) related to the system. Finally, if the safeguards are not enough to protect PEAR, feasible recommendation/s would be proposed. Thus, the same process is repeated step by step for all the nodes.

BPCL HAZOP had been successfully completed by brainstorming each unit with the multi-disciplinary team such as process engineers, DCS engineer, Process safety Engineer and Control & Instrumentation engineers led by the Chairman. Therefore, BPCL HAZOP quantitatively evaluated the severity and risk for each consequence and identified the gaps present in the process with the aid of above mentioned procedure.

Oil India Limited has awarded iFluids Engineering to carry out As-built P&ID and PFD drawings, HAZOP study, Quantitative Risk Analysis, Consequence Analysis, Preparation of SOPs & Manual of Heavy Crude oil and Natural Gas Production installations and Work over operations in Rajasthan Fields .Oil India Limited (OIL) is a premier national Oil Company engaged in the business of Exploration, Production & Transportation of Crude Oil & Natural Gas. It discovered commercially viable gas fields at Tanot, Dandewala and Bagitibba in Jaisalmer district of Rajasthan.

To operate the fields, OIL has two production installations such as Processing Centre (GPC) & Gas Gathering Station (GGS).12 wells were drilled in Tanot field out of which 4 wells are having pressure, which needs workover operation for revival. This resulted in setting up of a centralized Natural Gas Processing facilities named DND GPC (Dandewala Gas Processing Complex) with the capacity of handling 1 MMSCM of Natural Gas per Day.

The Baghewala field of OIL has very high viscosity in thousands of centipoise and is not producible by conventional production methods on a regular basis.OIL has implemented CSS (Cyclic Steam Stimulation) technique for extraction of heavy crude in some of its wells on pilot basis. Addition to above, Rig will be deployed for Workover operation. It is intended to carry out HAZOP, QRA Study and Consequence Analysis for all the three installations.

To access engineering information easily at the time of need OIL has planned to create As-built engineering information for the oil and gas productions/process units through latest software tools so as to get the relevant information thereby minimizing losses in the event of an incident

Scope of Work

Scope of HAZOP study shall include the following aspects in addition:

  1. Process Hazards
  2. Maintenance Hazards
  3. Electrical Hazards.
  4. Design Verification (Hazards)
  5. Instrument Hazards
  6. Fire & toxic Hazards etc

Creation of As-built P&ID and PFD Drawings using recommended software

Collection of input data through physical survey, input verification & creation of P&IDs and PFD's for each installation using recommended international standard practice & software.


During the HAZOP each P&ID, PFD, Operation Manuals will be considered in turn Section wise with defined nodes .Recommendation will be provided on Emergency Measures & statutory requirements

QRA studies

Quantitative Risk Analysis includes identification of Hazards, Selection of Scenarios, Risk contours, Effects & consequences, Likelihood Estimation & Risk Summation along with control measures conducted as per International accepted guidelines. Quantitative Risk Analysis (QRA) and Emergency Response and Disaster Management Plan are to be carried out as per the statutory guidelines like Mines Act-1952, OMR-2017, OISD

Consequence Analysis:

Consequence Analysis and Estimation is the methodology used to determine the potential damage or injury from specific incidents.

Completion Period

The period of completion of project is 1 year.


Oil India Limited(OIL) has awarded iFluids Engineering to carry out As-built engineering information for the oil and gas productions/process units. Oil India Limited (OIL) is a premier national Oil Company engaged in the business of Exploration, Production & Transportation of Crude Oil & Natural Gas. Its operations are largely based in Assam and Arunachal Pradesh the north eastern part of India.

Over the years various developments, related to oil/gas production, has taken place accordingly, the production/process installations for oil and gas have also been modified /augmented. However, engineering information for the changes could not be updated or maintained in proper form so as to access them easily at the time of need. Considering this, OIL has planned to create As-built engineering information for the oil and gas productions/process units, & plan to maintain this updated information in a scientific way through latest software tools so as to get the relevant information at the click of a mouse. This will in-turn help OIL to carry out various risk analysis study. These studies will help in taking appropriate measure and bring down the risk to as low as reasonably practicable and thereby minimize losses in the event of an incident.

Scope of Study

Following requirements have been identified in the scope of study

To create engineering information for the following type of installations spread over Assam and Arunachal Pradesh

To convert all as-built engineering information of above installations to digital format using appropriate software tools

The tentative list of installations in Assam are:


Mobilization & Creation of As-built P&ID and PFD Drawings using Intelligent P&ID software

Electrical Single Line diagrams (SLDs) to As-built status

As-built Piping & Plant Layout, Electrical, Instrumentation, Optical Fibre cable diagrams, Cable Schedule Layouts, Electrical System & equipment earthing and Fire Fighting System Drawings in AutoCAD Format

SOP, O&M Manual- Startup operating manuals for the units updated with and data sheet (Standard Operation and Maintenance Manual)

To carry out Hazard and Operability (HAZOP) study

To carry out Quantitative Risk Analysis

To carry out Consequence Analysis

End Users Training & Submission of reports

Time of completion


Indian Oil Corporation Limited has awarded iFluids Engineering to carry out HAZOP Study for Panipat Refinery & Purified Terepthalic Acid unit .The Panipat Refinery is Indian Oil's seventh and most technologically advanced public sector refinery complex in India. Covering approximately 4222 acres of vast land, located in Panipat. The Refinery's capacity was increased to 12 MMTPA in June 2006, and then to 15 MMTPA in December 2010. In addition, there is a plan in the works to increase capacity to 25 MMTPA in the near future to satisfy prospective demand.

The Refinery's major secondary processing units include the Catalytic Reforming Unit, Once Through Hydrocracker Unit, the Resid Fluidised Catalytic Cracking Unit, the Visbreaker Unit, the Bitumen Blowing Unit, the Sulphur Block, and the associated Auxiliary Facilities. A Diesel Hydro Desulphurisation Unit (DHDS) was later commissioned in 1999 to improve diesel quality.

Facilities to be covered under the Study includes:

PR (Panipat Refinery) Unit

Unit NameNo Of P&ID's
PR:CDU, VDU - 03, 04, 1946
PR:NSU-1 Revamp - 422
PR : OHCU - 542
PR : HGU - 620
PR : RFCCU - 741
PR : PSU - 3320
PR : CRU - 830
PR : DHDS - 5221
PR : VBU - 916
PR : BBU - 107
PR : Gasoline Merox - 125
PR : LPG Merox - 135
PR : ATF/SKO Merox - 154
Name: PR : SRU - 229
PR : SSRU - 4418
PR : ARU - 2110
PR : SWS-I (Refinery)1710
PR : SWS-II(Hydro processing) - 1810
OMS : OM&S + Offsites-LPG/Tank farm250
ETP : ETP-I - 6115
ETP : ETP-II - 6212
ETP : ETP-III - 2578
CPP : Utilities54
PRE : AVU-II - 7358
PRE : VDU-II - 7410
Unit Name: PRE : NSU-2 - 593
PRE : HCU - 7592
PRE : HGU - 76,7787
PRE : DCU Revamp - 7887
PRE : Cracked (DCU) LPG Merox - 795
PRE : DHDT Revamp - 7249
PRE : SRU-I - 5514
PRE : SRU-II - 567
PRE : TGU - 5714
PRE : ARU - 5129
PRE : SWS-I - 535
PRE : SWS-II - 544
PRE : SW Stripper (Hydroprocessing) - 205
PRE : SRU - 2531
PRE : TGU - 2614
MSQ : NHT - 30125
MSQ : PENEX - 30148
MSQ : RSU - 30212
MSQ : FCC GDU - 30346
MSQ : MSQU (offsites) - 30445

Total Nos. of P&ID's for HAZOP in the PR units are 1430

PTA (Purified Terepthalic Acid) Unit

Unit NameNo of P&ID's
PX-PTA : NHT, CCR with REGTR - 201, 202103
PX-PTA : Shell Sulfolane - 20436
PX-PTA : Parex - 20539
Unit Name: PX-PTA : XFU - 20639
PX-PTA : Isomer - 20730
PX-PTA : Tatoray - 20829
PX-PTA : BTF - 20919
PX-PTA : PTA-Oxidation/ Purification - 2122
PX-PTA : PTA N2 plant - 375

Total Nos. of P&ID's for HAZOP in the PTA units are 422

Total Nos. of P&ID's for HAZOP in PR & PTA units are 1852

Scope of Study

The HAZOP will be conducted to examine the overall Process design searching for operating deviations and procedures that can lead to hazardous situations or operability problems which  include:

Objective of the HAZOP Study


Mangalore Refinery and Petrochemicals Limited (MRPL) has awarded iFluids Engineering to carry out HAZOP study for the entire refinery complex and other facilities covering jetty, cross country pipelines, SPM, Aromatic Complex (around 2650 no of P&ID's) of MRPL located in Karnataka.The refinery has got a versatile design with high flexibility to process Crudes of various API and with high degree of automation & a design capacity to process 15 million metric tons per annum (MMTPA).

MRPL owns and operates cross country pipelines to receive crude oil and transport finished products from and to Jetty facilities of New Mangalore Port respectively. Further, MRPL owns and operates Single Point Mooring (SPM) facilities off the coast of Mangalore to receive large to very large crude oil carriers

Facilities to be covered

HAZOP study to be carried out on all latest updated Piping and Instrumentation Diagrams (P&IDs) of Process and Utility plants.

Unit DescriptionNo of P&ID's
 SRU -112
PHASE 1 utilities33
Jetty facilities20
CDU-2/ VDU-2/ NSU-245
SEPU System04
Naphtha Hydro treating unit 25
PHASE 2 utilities50
N2 Plant32
PHASE 3 Offsites & Utilities137
Bitumen Drum filling unit01
Black Oil Truck Loading Facilities04
SPU Phase-201
White Oil Truck Loading Facilities04
CCR Regeneration (CCRG)05
Naphtha Hydro treating unit25
CCR Platformer unit (CCRP)38
Shell Sulfolane unit (SSU)21
Tatoray  unit15
Block-2 Utility31
Xylene  fractionation  unit  (XFU)31
OSBL andISBL Tank farm area68
Effluent treatment plant (ETP)27
Solid waste disposal & handling facility47
Laboratory draining system facility2
Effluent pre-treatment plant(EPTP)6
Cooling tower Blow down reverse osmosis plant (CTRO)6
Fire water system1
Nitrogen Plant2
Instrument air & Plant air system(IA & PA)2
PHASE 2 utilities27
Bitumen Drum filling uni01
Black Oil Truck Loading Facilities04
Block-1 Utility47
OSBL andISBL Tank farm area68
Shell Sulfolane unit (SSU)28
N2 Plant35

Approximate no of P&ID's for HAZOP study in the refinery is 2650.

Scope of work

HAZOP Methodology

Completion Period

The project will be Completed within 18 months from the date of issue of LOA


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