HAZOP, HAZID, SIL STUDY and SIL VERIFICATION study for “MWP 01 & 19 Alkali Surfactant Polymer (ASP) Flood

HAL OFFSHORE has awarded iFluids Engineering to carry out HAZOP, HAZID & SIL study for CAIRN India at HAL OFFSHORE, Mumbai for its MWP 01 & 19 Alkali Surfactant Polymer (ASP) Flood at Barmer, Rajasthan as part of Process Hazard Analysis (PHA).

Contract area RJ-ON-90/01 in the Indian state of Rajasthan is operated by Vedanta Limited, Cairn Oil & Gas, in a joint venture with ONGC.

CAIRN discovered oil and gas fields in RJON-90/01 block, named them as Mangala, Aishwariya, Bhagyam, Saraswati, Shakti, Raageshwari and others. The largest oil fields in the RJ block are those in the northern region, including Mangala, Bhagyam, and Aishwariya.

The Mangala Processing Terminal (MPT) in the Barmer district of Rajasthan processes the output from every well pad of Mangala, Bhagyam, Aishwariya, and other satellite fields.

Mangala is one of the major fields originally developed under water flood and is currently under polymer flood. Based on the successful ASP Pilot trial in Mangala field, Cairn intends to implement ASP flood as a part of Mangala FM1 Layer in Mangala. As part of early implementation plan, Well Pad 01 and 19 have been selected for Phase 1 ASP Flood Implementation.

The scope of work is to carry out Hazard and Operability (HAZOP), Hazard Identification (HAZID) & Safety Integrity Level (SIL) study for MWP 01 & 19 Alkali Surfactant Polymer (ASP) Flood at Barmer, Rajasthan.


HAZOP is a systematic and qualitative technique used to check for the deviation in plant’s normal operating conditions which can leads to hazardous situations or operating issues in the plant. To identify risks and operational disruptions in the plant, guidewords (low, high, less, more) were utilized with data like pressure, temperature, flow-rate, and level.

Any facility’s HAZOP study provides information on both the plant’s general safety features and daily operations. The following list includes some of HAZOP’s key characteristics.

  • Identification of hazards and operating problems.
  • To recommend the changes in design, procedure, etc to improve safety.
  •  Identification of hazards from equipment failure, instrument malfunction and operational issues
  •  A HAZOP analysis is conducted during the design and procurement stages to thoroughly review the P&ID and find any variations from standard procedures that could result in operational problems or risks.
  • HAZOP can be used to recommend safety investigations for effects that cannot be avoided by applying current safeguards or by suggesting new safeguards, in addition to these other uses.


Hazard Identification (HAZID) Study is a structured and systematic evaluation of a planned and/or existing operation to identify and evaluate potential hazards in design and operation. This study is carried out by a team of experts from different disciplines. The team looks at each section of a facility and analyses their consequences against any existing safeguards.  The effects of the identified risks on property, safety, and the environment are evaluated.

The objectives of HAZID study include:

  • The detection of potentially dangerous internal and external events that, if they occur, could endanger people, property, and the environment.
  • Quantitatively evaluate the risks associated with the identified hazard occurrences and their propensity to occur.
  • Assess the safety precautions suggested in preventing, mitigating, and controlling the potentially dangerous results.
  • Identifying the remaining hazardous events that require additional quantitative assessment and analysis.
  • Identification of health and environmental impacts associated with the Project.

A structured method to ascertain the probable effects of the following is required for the HAZID:

  • The surroundings on the facilities
  • The facilities on their surroundings
  • The facilities on health.


As per the scope of SIL Classification study, safety instrumented functions (SIFs) were identified in the P&IDs and the C&E matrices, relevant to project, having the main objectives to:

  • Identify potential risks to the people, environment and assets due to failure of Safety Related Systems and associated facilities in the plant to operate on demand.
  • Establish the fundamental performance standards for all safety-related instrumented equipment in order to “As Low as Reasonably Practically” reduce the aforementioned hazards.

SIL Methodology is discussed below: 

  • Identify all Safety Integrity Function (SIF) loops from Cause and Effect diagram (C&E) and HAZOP report
  • Identify initiating causes and their initiating likelihood
  • Determine the scenario consequence level and severity with respect to people, environment and assets
  • List out the independent protection layers (IPLs) that can mitigate the initiating causes
  • Calculate the Probability of Failure on Demand (PFD) and in turn analyze the SIL requirement
  • Provide recommendation if there is additional Safety Instrumented System (SIS) required


HAZOP, HAZID & SIL study for ASP flood project of CAIRN Oil & Gas was conducted in presence of muti-disciplinary team from various departments such as Process Engineering, Process Safety, Projects, Instrumentation, Maintenance, Electrical etc.

Facilities covered for above mentioned safety assessments are

  •  Mangala well pad – 01 (MP-01)
  •  Mangala well pad – 12 (MP-12)
  •  Mangala well pad – 19 (MP-19)
  •  Sulphate Removal Plant (SRP)

HAZOP, HAZID & SIL study findings were recorded by the team and suitable recommendations were also made based on the mutual discussion among the team members. HAZOP & HAZID was conducted unit wise using basic engineering documents like PFD, P&ID, Process Design Basis (PDB) & plot plan whereas SIL study was followed by HAZOP using P&IDs and Cause & Effect (C&E) diagrams.  On the basis of the session’s conclusions, recommendations were made. Additionally, some broad suggestions for the entire institution were put up.