Elixir Engineering  was awarded to perform Hazard and operability (HAZOP) study for SAHMAH - Hydrocarbon Finder

Project Summary

Hydrocarbon Finder Oman (HCF) was established in 2015 to acquire, explore, develop and produce oil and gas resources in Oman.Hydrocarbon Finder currently has two assets: Block 7 (100%), and Block 15 (90%).

Block 7 Overview:

• Covers an area of approximately 2,300 km².
• Contains three producing fields: Sahmah, Ramlat, and Rija.
• Sahmah Field: Production commenced in 1980.
• Total oil produced to date: 55 million barrels (MMbbl).
• Oil produced is of light quality with an average gravity of 44° API, sold as Oman Blend.

Infrastructure:

• Primary infrastructure is centered in Sahmah Field.
• Facilities include the main tank, camp/office, staff accommodation, and processing facility.

Field Locations:

• Ramlat Field: Located 45 km from Sahmah.
• Rija Field: Located 30 km from Ramlat.
• Oil from Ramlat and Rija is transported via truck to the Sahmah processing facilities.
• From Sahmah, oil is piped 100 km to the main PDO oil line.

Recent Developments:

• HCF has recently completed the transition of Block 7 assets and personnel from Petrogas to HCF.

Current Production:

• Block 7 is currently producing less than 1,000 barrels of oil per day (BOPD).

HCF's focus is on significantly increasing oil production in the short, medium, and long term.

Immediate actions include:

• Optimizing completions.
• Re-completions.
• Targeting bypassed reserves.

Block 15 Overview

• Block 15 is located in Northern Oman, within the Foreland sub-basin, covering an area of nearly 1400 sq km.
• The most prospective reservoir horizons are expected to be the Natih and Shuaiba formations.
• These formations are present in permits situated immediately south of Block 15.

Three wells have been drilled in Block 15:

• Wadi Saylah
• Jebel Aswas
• Jebel Aswas

• All wells encountered hydrocarbons.
• The permit area is covered by 2D seismic data, with a 3D seismic survey focused on the Jebel Aswas/Wadi Saylah region.

Process Description:

• Main Station

Main Station (SAH-02 Production Facility):

Components included

• Flare network
• Components include:
• Manifold area
• Test Separator
• Production Separator
• Crude Storage Tanks
• Oil Skimming Tank
• Gas Compressor Station
• Water injection pumps
• Crude transport pumps
• Gas Scrubber Unit

• The produced crude is stored in the facility crude storage tanks and transported to 10km Booster pumping station through trucks by truck loading pumps.
• In 10km Booster pumping station, the crude is unloaded through unloading pumps and stored in temporary crude storage tanks.
• To 41km Booster pumping station, crude is transferred from 10km booster pumping station by Crude oil export pumps and respective pipeline.
• The 41km Booster pumping station consist of three numbers of Storage tanks and two numbers of Crude transfer pumps with capacity of 11 Cu.m/hr.
• The stored crude is pumped from 41km Booster pumping station to PDO MOL facility by this pumps and respective pipeline.

Inside PDO MOL facility, Pig receiver facility, Flow metering System is located. From the flow metering skid, the measured crude is connected to PDO Main Oil Line.

WH-02 & WH-03

Components Included

• Manifold area,
• Test Separator,
• Production Separator,
• Crude Storage Tanks,
• Oil Skimming Tank,
• Gas Compressor Station,
• Water injection pumps,
• Crude transport pumps,
• Gas Scrubber Unit
• Flare network.

• The produced crude form WellHead-02 enters the production separator (SAH-02), Gases are vented for flare, drain pit recovers water from water boot of the production separator.
• Oil separated is stored in 2 storage tanks and loaded to trucks by loading pumps.
• For Wellhead-03, Produced crude passes to manifolds and production separator (SAH-03), Gases are vented to flare, drain collects the water from water boot of the production separator.
• Separated oil is stored in 3 Storage tanks and loaded to trucks by loading pumps.

• The loading pumps works on Auto Cut ON / OFF system, to indicate the full load of the truck. A 3-inch valve is provided for the pump change over operations between two wellhead’s storage tanks.
• Instrument air is produced by compressor, airborne contaminants are removed through air scrubbers and injected into well heads (to increase the viscous flow of produced oil) and chemical loading pumps

Elixir Engineering performed the Hazard & Operability (HAZOP) study for Hydrocarbon Finder.

Hazard & Operability Study (HAZOP)

• Hazard and Operability (HAZOP) 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 engineers from different disciplines.
• The team looks at each section of a plant or system or operation (node), considers potential deviations from intended operation and analyses their consequences against any existing safeguards.
• Impact of identified hazards on safety, asset and environment are assessed.
• HAZOP is a guideword driven brainstorming technique.
• Team members contribute based on their collective experience and lessons learnt from past projects. HAZOP study records the identified hazards without proposing any solution, unless a solution is obvious.
• Proposed solutions may include additional safeguards or operational procedures as necessary.
• The study record serves as a guide to determine the Health, Safety and Environment (HSE) issues to be resolved during the project.

Purpose of HAZOP

Hazop for any project or modification serves many purposes including

• Identify the hazards inherent to the proposal.
• Identify the credible equipment instrument failure likely to lead to accident scenarios / hazards / operability problems
• In addition to these issues, Hazop occasionally identified items which could improve unit operations and efficiency.

Methodology

The HAZOP focuses on the process / utility system and associated interfaces. The basic concept of a HAZOP study is to take full description of the process and question every part of it during brain storming meetings attended by the different specialists involved in the process design to discover firstly what deviations from the intention of design can occur and what their causes and consequences may be.

The main steps involved in a HAZOP study are as follows

1. Select the node (Line, equipment or a system) on the P&ID;
2. List of the intention & process parameters, guidewords for the nodes;
3. List all deviations and ignore deviations that are not meaningful and apply the deviation;
4. Brainstorm and list various causes of the deviation and ignore causes that are not credible;
5. Determine the consequences of the deviations due to each listed credible cause;
6. Identify safeguards already provided in the system
7. Suggest recommendations / actions, should the safeguards be inadequate;
8. Repeat steps 3 to 7 for each deviation
9. Repeat steps from one (1) to eight (8) on the next node until all the nodes are covered.

Elements of HAZOP study:

Node definition

The HAZOP study progresses through the plant node by node. The selection of the node sizes and the route through the plant is made before the study by the facilitator. The node should be described in terms of: -

• Brief description of the node
• Typical operating and design conditions
• Method of operation and maintenance, and requirement for operator intervention

Parameters

Flow, Pressure & temperature are usually regarded as the main parameters/elements. Additional parameters relate to general considerations like maintenance, safety, relief, corrosion/ erosion, instrumentation, start-up & shutdown, etc. Some of these may be selected for nodes in a study as appropriate based on relevance and concerns expressed by team members.

Guidewords

Guide words are simple words or phrases used to qualify or quantify the intention and associated parameters in order to suggest deviations. Standard guide words; No/less, more/Less, As Well As/Part of, Reverse/Other Than, Early/Late, Before/After are applicable to each parameter. ‘Other Than’ is a very popular ‘catch all’ guide word at the end of each parameter.

Causes

All credible/ plausible scenarios leading to the deviations, should be considered when determining causes. The Causes should be “Local” to the node being studied. The consequences are deliberated only after listing all the Causes. Two events happening simultaneously without any correlation should not be considered.

Consequence

“Global” effects should be considered for the consequences i.e., keep researching the resulting reactions till you reach the Ultimate Consequence of a deviation.

Safeguards

Risk is a function of both Probability and Consequence. Safeguards reduce either Probability or Consequence. These could be either related to hardware or operator practices & intervention., While selecting safeguards, you may consider engineering or administrative safeguards, but it is necessary to check whether these are existing & functional for the operating plant.

RECOMMENDATIONS

• What is to be done?
• Where is it to be done?
• Why is it to be done?

Recommendations should be reported using action-based words (such as Check, Provide, Consider, Ensure, Review etc.), and assigned to specific work groups. It should be verified whether three chief questions have been explained, viz.