Post- Graduate Experience Report Sample

POST GRADUATE EXPERIENCE REPORT FOR NIGERIAN SOCIETY OF ENGINEERS (NSE) MEMBERSHIP EXAMINATION (DECEMBER, 2015)

BY JOHN MARK

ABSTRACT

This report summarized the engineering experience of the author for the membership examination of the Nigerian Society of Engineers (NSE) in April 2013. The report was structured as stated below: Introduction chapter introduced the profile of the author and the purpose of the document. Chapter one summarized the detail of “Design of gas supply pipeline to PHCN Delta IV”. Chapter two focused on “Design of fire water spray system for the pressure reduction and metering station of PHCN Delta IV”. Chapter three summarized the project report of “Compressed Natural Gas Mother Station (CNG) Engineering, Procurement and Construction” The report of the project in each of the main chapters (1, 2 and 3) contained: title of the project, statement of the problem, solution provided, problems encountered, conclusion and recommendation. In each of the projects reported, the objectives of carrying out the exercise were fully met. For the “Design of gas supply pipeline to PHCN Delta IV” a 20 inches, Schedule 40, API 5L X 65(Grade B), Carbon Steel Pipe was the final design. A fire water spray system was successfully designed based on the “Single Fire Risk” for the PHCN Delta IV PRMS. For the Compressed Natural Gas Mother Station (CNG) Engineering, Procurement and Construction, the objective was met in three phases. The first part involved successful management of the remaining design phase. The second part involved managing the scheduled construction work for the period. The third section involved successful management of delivery of the procured equipment skid to Nigeria from Italy

TABLE OF CONTENTS ABSTRACT....................................................................................................................................1 INTRODUCTION.........................................................................................................................3 CHAPTER ONE: DESIGN OF GAS SUPPLY PIPELINE TO PHCN DELTA IV.................8 1.1 Statement of the Problem.......................................................................................................8 1.2 Design Solutions....................................................................................................................8 1.2.1 Understanding of the design problem and gathering of basic design data......................9 1.2.2 Codes and Standards.....................................................................................................10 1.2.3 Options for pipe sizing..................................................................................................10 1.2.4 Sizing of pipe.................................................................................................................11 1.2.5 Calculation of pipe wall thickness.................................................................................12 1.2.6 Calculated External Pipe Diameter...............................................................................13 1.2.7 Recommended Pipe.......................................................................................................13 1.2.8 Transportation simulation and hydraulic studies...........................................................13 1.3 Problems Encountered.........................................................................................................14 1.4 Conclusion...........................................................................................................................15 1.5 Recommendation.................................................................................................................15 CHAPTER TWO: DESIGN OF FIRE WATER SPRAY SYSTEM FOR THE PRESSURE REDUCTION AND METERING STATION (PRMS) OF PHCN DELTA IV.......................16 2.1 Statement of the Problem.....................................................................................................16 2.2 Design Solutions..................................................................................................................16 2.2.1 Fire outbreak assumption..............................................................................................17 2.2.2 Design Basis: Fire water demand..................................................................................17 2.2.3 Fire water source.........................................................................................................17 2.2.4 Fire water pressure........................................................................................................17 2.2.5 Fire pump system..........................................................................................................17 2.2.6 Looping.........................................................................................................................19 2.2.7 Criteria for above and underground network................................................................19 2.2.9 Protection for underground pipelines............................................................................20 2.2.10 Protection for above ground pipelines.........................................................................20 2.2.11 Sizing of fire water distribution ring main..................................................................20

2.2.12 Friction loss calculation in water distribution pipe.....................................................21 2.2.13 Pipe support.................................................................................................................22 2.2.14 Fire hydrants................................................................................................................22 2.2.15 Monitors......................................................................................................................23 2.2.16 Fire Hose Boxes..........................................................................................................24 2.3 Problems Encountered.........................................................................................................24 2.4 Conclusion...........................................................................................................................24 2.5 Recommendation.................................................................................................................25 CHAPTER THREE - COMPRESSED NATURAL GAS MOTHER STATION (CNG) ENGINEERING, PROCUREMENT AND CONSTRUCTION (EPC)..................................26 3.1 Statement of the problem.....................................................................................................26 3.2 Solution Provided................................................................................................................27 3.3 Problems encountered..........................................................................................................27 3.4 Conclusion...........................................................................................................................28 3.5 Recommendation.................................................................................................................28

INTRODUC TION John Mark graduated from Ladoke Akintola University of Technology (LAUTECH) Ogbomoso in 2006 with a second class upper grade in Chemical Engineering. He has since then involved in engineering project delivery. He first worked with Scanpin Computers in Sango Ota, Ogun State between 2007 and 2009. He later joined the workforce of San Miller Limited Abuja office as a Process and Technical Support Engineer in 2009. San Miller Limited is an engineering consulting firm with over 25 years’ project experience in engineering design and process simulation consultancy in oil and gas sector. In 2012 he became a Process/Project Development Engineer in respond to the need of San Miller Limited. He was seconded as Project Manager to Ener-Gas International Investment Limited in September 2012 for a period of four months to manage engineering, procurement and construction of a compressed natural gas mother station. He returned back to San Miller in January 2013 to retain his position as a Process/Project Development Engineer. As a Process and Technical Support Engineer, Mark was involved in process design for oil and gas production facilities. He also offered product training on Aspen One Engineering (A suite of process simulation software products sold by San Miller Limited on behalf of its owner – Aspen Technology Incorporated in Nigeria). As a Process/Project Development Engineer, Mark combined project management with process engineering for oil and gas upstream projects. His responsibilities included: process route selection, development of process flow diagram, process equipment sizing, pipeline sizing and hydraulic studies, development of process datasheet, project planning, project monitoring and control, cost estimation, etc. Mark in the last six years has been involved in the following engineering projects: I.

Compressed Natural Gas Mother Station (CNG) Engineering, Procurement and Construction (EPC)   

Type of Project: EPC Project Position: Project Manager Client: Oando Gas and Power Limited

II.    III.

(FEED), Detailed Engineering) Project Position: Process and Project Engineer Client: Federal Ministry of Petroleum Resources Project Management Planning Consultancy Service Gas Supply Pipeline Delta IV

   IV.

(Procurement and Construction Phases) Type of Project: Project management consultancy Project Position: Project Engineer Client: Federal Ministry of Petroleum Resources Design of Fire Water Spray System for the Pressure Reduction and Metering Station

   V.    VI.

(PRMS) of PHCN Delta IV Type of Project: Front End Engineering Design (FEED) Project Position: Process Engineer Client: Federal Ministry of Petroleum Resources Design of Gas Supply Pipeline to PHCN Delta IV (Phase 1) Type of Project: Engineering Design (Conceptual, Front End Engineering Design (FEED), Detailed Engineering) Project Position: Process Engineer Client: Federal Ministry of Petroleum Resources Project Management Consultancy Services for Calabar-Umuahia-Ajaokuta Detailed

   VII.

Gas Supply Spurline to PHCN Delta 1, 2, 3 and Delta IV Type of Project: Engineering Design (Conceptual, Front End Engineering Design

Engineering Type of Project: Engineering design review/Project management consultancy Role: Process Engineer Client: Federal Ministry of Petroleum Resources

Study wide study on Agbami FPSO seawater system  Type of Project: Process Simulation  Role: Process Engineer  Client: Federal Ministry of Petroleum Resources

Mark has undergone various local and international trainings such as: 

Fundamental of Bentley MicroStation (Plant design software course)

Bentley Systems (SA) Ltd, Rivonia, South Africa (2012) 

Fundamental of Bentley OpenPlant (Plant design software course) Bentley Systems (SA) Ltd, Rivonia, South Africa (2012)



Aspen InfoPlus.21 Real Time Information Management Foundation (Information Management System for Manufacturing Plant) Aspen Technology Inc, Abuja (2012)



SAP CRM Training (Online Course) (Enterprise resources planning course) Bentley Systems (SA) Ltd (2012)



Flare System Design and Radiation Analysis using Flaresim Softbit, Abuja (2011)



Project Management Professional Course Afrihub, Abuja (2010)



Process Modelling using Aspen Hysys San Miller Ltd, Abuja (2009)



Modelling of Pipeline and Fire Protection System using Sunrise Pipenet Modules San Miller Ltd, Abuja (2009)



Health Safety and Environment Awareness Course MMC Management Consulting, Lagos (2007)

Mark was certified as a Project Management Professional (PMP) by Project Management Institute (PMI) in 2012.

This report summarized the engineering experience of the author for the membership examination of the Nigerian Society of Engineers (NSE) in April 2013. The report was structured as stated below: Introduction chapter introduced the profile of the author and the purpose of the document Chapter one summarized the detail of “Design of gas supply pipeline to PHCN Delta IV”. Chapter two focused on “Design of fire water spray system for the pressure reduction and metering station of PHCN Delta IV”. Chapter three summarized the project report of “Compressed Natural Gas Mother Station (CNG) Engineering, Procurement and Construction” The report of the project in each of the main chapters (1, 2 and 3) was written in this format:     

Title of the project Statement of the problem Solution provided Problems encountered Conclusion and Recommendation.

CHAPTER ONE: DESIGN OF GAS SUPPLY PIPELINE TO PHCN DELTA IV

1.1 Statement of the Problem

The Federal Government of Nigeria in pursuit of the desire to generate sufficient electricity power to meet the demand of the country decided to develop a pipeline to supply natural gas to the Power Holding Company of Nigeria (PHCN) power plant located at Ughelli area of Delta State.

The proposed pipeline was meant to start at a point on the Escravos Lagos Pipeline (ELP) and terminated at a proposed processing facility in Ugheli. The length of the pipeline has already been established by survey to be 3.6 km. This engineering design study was established to recommend a suitable pipe (with adequate size, wall thickness and other necessary properties) for the transportation of 300MMSCF/D of natural gas from the tie-point to the processing facility.

The study was also meant to carry out

comprehensive transportation simulation or hydraulic studies to:    

Confirm the calculated pipe size Confirm possibility of hydrate formation and multiphase flow at any point of the pipeline Produce material and energy balance for the pipeline network Propose process route for the processing facility that will treat the gas to PHCN specifications.

1.2 Design Solutions The approach adopted to carry out the studies was as discussed below: 

Understanding of the design problem and gathering of basic design data



Code and standard consideration



Proposing of various options for pipe sizing



Sizing of pipe based on optimal design option



Calculation of pipe wall thickness



Proposing final pipe wall thickness which included consideration for corrosion allowance



Transportation simulation and hydraulic studies.



Analysis of results



Reporting

1.2.1 Understanding of the design problem and gathering of basic design data Detailed analysis of the design problem based on the available information revealed that the gas pipeline is a transmission line. The basic designed data obtained from the client and Nigerian Gas Company (NGC), the operator of ELP is presented below: Composition

Mol %

C1

81.64

C2

5.91

C3

3.77

iC4

1.24

nC4

1.18

C5+

1.60

H2S

-

N2

0.69

CO2

3.97

TOTAL

100.0%

Conditions and Properties Molecular weight of the gas: 21 Specific Gravity: 0.7 Gross Calorific Value : 900 – 1150 Btu/ScF Tie-in Pressure: 40-76Barg Delivery Temperature: 20oC to 38 oC . Design Volume of Gas: 300 MMSCF/D

1.2.2 Codes and Standards The pipeline was designed primarily based on requirements of ASME B 31.8 (Gas Transmission and Distribution Piping System), API RP 14E (Recommended Practice for Design and Installation of Offshore Production Platform Piping System) and Department of Petroleum Resources (DPR) In addition API 5L (Specifications for Line Pipe) was also considered.

1.2.3 Options for pipe sizing Pipes are always sized in the industry based on pressure drop. Sometimes for preliminary design purposes when pressure loss is not a concern, pipe is sized on the basis of allowable velocity. At this level of the project, pipe was considered to be sized based on pressure drop. Velocity allowance would be considered later during transportation simulation and hydraulic studies. During the course of this project, various mathematical models for calculating pressure loss in gas were suggested for sizing this pipe. The suggested models were: 

Weymouth equation



Panhandle A equation



Panhandle B equation



Spitzglass equation

Weymouth equation has limitations with respect to this type of flow. Its accuracy was limited to sizing of short pipe within a production facility whose gas pressure fell below 450kPa. Also the gas velocity and the Reynolds number (Re) must be low and the flow must be laminar before it can be used. Since the operating pressure of this gas was above 450kPa and the line was transmission type (3.6km) with high tendency of turbulent flow (Re > 2000) Weymouth equation was disqualified. Spitzglass equation also has limitations with respect to this type of flow. It usually gave misleading results for pipe diameters over 10 inches. Since the gas throughput expected to flow

through the pipe was high, there is high tendency of having pipe diameter greater than 10 inches hence Spitzglass equation was disqualified. Panhandle A and Panhandle B equations were the best options for sizing the pipe at hand. The two models were developed for large-diameter, long-pipelines with high-pressure. Both Panhandle equations are dependent on Reynolds number but the Panhandle B is less dependent than the former because it included implicit values for pipe roughness for each diameter to which it is applied which makes it (Panhandle B) to be considered for this sizing.

1.2.4 Sizing of pipe The pipe was sized based on modified Panhandle B equation given below

(

2

P ₁ −P ₂ Q=0 . 00128084 L

2 0 .51

)

D2 .53

Where Q = Volumetric flow rate of the gas (MMSCF/D) P1 = Upstream pressure (psia) P2 = Downstream pressure (psia) L = Length (mile) D = Internal pipe diameter (inches “in”)

Sizing assumptions used for the calculation were stated below: P1 = 1117psig (worst case scenario) P2 = 1092 (obtained from process simulation result) Q = 300 MMSCF/D L = 2.24 Mile (3.6km) The calculated internal pipe diameter was 18in.

(1.1)

1.2.5 Calculation of pipe wall thickness The “Oil Pipeline Document” published by DPR stipulates the use of API 5L X 65 for the large diameter pipeline operating under high pressure. The pipe wall thickness was calculated based on the steel pipe design formula of ASME B 31.8, paragraph 841.11, based on design pressure (100 barg = 1470 psig).as given below:

P=

2 st FET D

(1.2) Where D = Pipe outer diameter = (18 + 2t) in. (Note “t” is the pipe wall thickness) S = Specified min. yield strength = 65,000 psi (as per API 5L X 65) E = Longitudinal Joint Factor = 1.0 T = Temperature Derating Factor = 1.0 F = Design Factor = 0.5 (Considering the available survey data and future development potential of the areas forming the pipeline route, Location Class 3 has been selected for the pipeline design owning to the long life design criteria by the client and the fact the town is rapidly developing.) P = Design Pressure for the pipeline = 1470 psig Pipe wall thickness “t” = 0.426” (10.82mm)

After determining the pipe wall thickness that meets mechanical requirements, such as pressure, temperature and weight of equipment, an extra thickness called "corrosion allowance” was added to the pipe wall thickness to compensate for the metal expected to be lost over the life of the equipment. Based on requirement DPR and Nigerian Gas Company (NGC), 3mm corrosion allowance was recommended. However in view of the long life span (25 years) proposed for this pipeline, a

safety factor of 2mm was further added to the recommended corrosion allowance which put it at 5mm. The final recommended wall thickness was 15.82mm (0.62’’) 1.2.6 Calculated External Pipe Diameter The calculated external pipe diameter based on pipe wall thickness that meets mechanical requirements and corrosion allowance to compensate for the metal expected to be lost over the life of the equipment was 20 inches (18.00 + 2(0.62)) 1.2.7 Recommended Pipe Based on calculation the design pipe was 20 inches, 15.82mm wall thickness, API 5L X 65(Grade B), Carbon Steel Pipe was initially recommended but after availability, a standard pipe of 20 inches, Schedule 40, API 5L X 65(Grade B), Carbon Steel Pipe was chosen. 1.2.8 Transportation simulation and hydraulic studies The studies were meant to confirm the suitability of the pipe diameter based on API RP 14E’s Velocity limitation of 60ft/s and elevation changes as provided by surveying. Aspen HYSYS 7.3 version was used to simulate the pipeline network for two pipe diameters (18 inches Schedule 40 and 20inches Schedule 40) at two most extreme operating pressure conditions (40 barg and 76barg) at various operating temperature ranging from 20oC to 38 oC. Based on the velocity limitation, 20 inch, schedule 40, carbon steel pipe was found appropriate for the desired throughput at all considered operation conditions. The valid assumptions used in the model were: Roughness of the pipe: 0.0018inches Average elevation change = 1.2 (based on surveying data) Overall Heat Transfer Coefficient = 28.618Kj/h-m2 oC. The simulation studies also used to propose process route for the processing facility that will treat the gas to desired specifications of 30barg and produce material and energy balance for the entire pipeline facilities

The outlet gas from the pipeline at all operation conditions considered could not meet the pressure requirement of 30barg which necessitated a need for pressure reduction station. Based on standard practice and the need to ensure that the gas is free of unwanted particles and liquid, a filter separator was proposed as the first unit in the pressure reduction facilities. Next to the filter separator, pressure reduction unit was proposed to reduce the pressure of the filtered gas to 30barg but after simulation studies it was discovered that the outlet fluid was a gas-liquid mixture which cannot be used for power generation. A heater was then proposed to preheat the filtered gas before it enters the pressure reduction which the simulation material and energy balance confirmed appropriate. The preheating eliminates the tendency of hydrate formation and multiphase flow throughout the facilities. The main process units for the PRMS include: i.

Filter separators

ii.

Liquid handling facilities

iii.

Heating system

iv.

Pressure reduction unit

v.

Gas metering unit

1.3 Problems Encountered The problem encountered during the course of doing the design work and the solution provided were: 

Government bureaucracy which affected the project schedule. This was addressed by



working sometime on Saturday. Hindrance from project host communities to gain access to site. A better community relation approaches were formulated to take care of that

1.4 Conclusion The major objective of this project was to recommend a suitable pipe (with adequate size, wall thickness and other necessary properties) for the transportation of 300MMSCF/D of natural from the tie-point to the processing facility and to propose units for the pressure reduction facilities.

This objective was met in three phases. The first part involved sizing of pipe based on modified Panhandle equation (a pressure loss model) to determine the best internal diameter for the pipe. The second part involved determining the pipe wall thickness based on mechanical requirements and corrosion allowance. The third section involved comprehensive transportation simulation and hydraulic studies to confirm the calculated pipe size, confirm possibility of hydrate formation and multiphase flow at any point of the pipeline, produce material and energy balance for the pipeline network and propose process route for the processing facility that will treat the gas to desired specifications. Conclusively, a 20 inches, Schedule 40, API 5L X 65(Grade B), Carbon Steel Pipe was the final design. 1.5 Recommendation 

Additional flow assurance studies should be carried for the entire length of the pipe



Further studies should be carried out to confirm the corrosion allowance considered in the design

CHAPTER TWO: DESIGN OF FIRE WATER SPRAY SYSTEM FOR THE PRESSURE REDUCTION AND METERING STATION (PRMS) OF PHCN DELTA IV 2.1 Statement of the Problem The Ministry of Petroleum Resources decided to develop a Pressure Reduction and Metering Station (PRMS) to treat and meter natural gas to the Power Holding Company of Nigeria (PHCN) power plant located at Ughelli area of Delta State. For safety consideration, fire water spray system was proposed as part of the station. Fire water spray system could be used for fire extinguishment, fire control, cooling of equipment and protection of equipment and personnel from heat radiation.

The proposed fire water spray system primarily comprised of 

Fire water storage tank,



Fire water pumps



Distribution piping network



Hydrants and



Monitors.

This engineering design study was established to select and size the main units of the system. The study was also meant to carry out hydraulic calculation for the water distribution network. 2.2 Design Solutions The approach adopted to carry out the studies is as described below: 

Understanding of the design problem and gathering of basic design data



Code and standard consideration



Proposing of various options for selection and sizing



selection and sizing of line and units



Hydraulic calculation for water distribution line

2.2.1 Fire outbreak assumption Fire water spray system design was based on the “Single Fire Risk” concept which means that only one major fire will occur at a time and fire will not take place simultaneously at different locations. 2.2.2 Design Basis: Fire water demand The design flow rate or fire water demand of 530 m 3/h was computed based on the largest area with equipment skids that can catch fire easily in the open space of the Pressure Reduction and Metering station.

2.2.3 Fire water source The water for the fire water system was designed to come from a borehole dedicated for such function. Fire water would be stored in an overhead storage tank made of steel on aggregate reinforced concrete plinth foundation and support based on NFPA 15 (Standard for Water Spray Fixed Systems for Fire Protection) The effective capacity of the tank above the level of suction point was designed for 4 hours working capacity of pumping system. 2.2.4 Fire water pressure The fire water system was designed to operate at a minimum residual pressure of 7 barg at the hydraulically remotest point of application at the designed flow rate at that point. The fire water network was design to be kept pressurised by a jockey pump which will maintains the system pressure at 7 barg by starting and stopping automatically based on the system pressure. 2.2.5 Fire pump system The fire water pump system was designed to deliver the pressure and flow required for the operation of water based systems sufficient to meet typically the single largest credible fire in a fire area plus any anticipated manual fire fighting demand (monitors/hydrants). The fire pumps was designed to deliver fire water at minimum of 7 barg at the hydraulically most remote monitor or hydrant with the largest fire water requirement in the biggest area. In line with codes and standards requirement, the fire water pumps consist of two (2) main pumps (2 Diesel engine driven centrifugal pumps) with each pump being able to provide at least 100 % of the maximum fire water requirement. Assuming one fire pump accidentally fails when called to operate; the other pump can come in. Each of the two pumps was proposed to be horizontal centrifugal type. There would also be in addition, a jockey pump with a minimum capacity of 16 m 3/hr (3% of the design fire water rate) and maximum capacity of 53 m 3/hr (10% of the design firewater rate) and a minimum discharge pressure of 9 barg (which is 2 bar above minimum fire water pump discharge pressure at the hydraulically most remote monitor or hydrant.)

The specification of fire water pump summarized as described in the table below:

Rated S/N

Service

Type

Rated Capacity (m³/h)

Head

Driver

(barg) 1

Fire Water Pump (Duty)

2

Fire Water Pump (Stand By)

3

Jockey Pump

Centrifugal Horizontal Centrifugal Horizontal Centrifugal Horizontal

636

13

636

13

53

13

Diesel Engine Diesel Engine Electric Motor

Fire Water Pumps, Drivers and Controllers were proposed to be installed in the Fire Pump House, which was decided to be located in the safe area (non hazardous area). The fire water pump system was designed to be operated as follows: The main fire water pump shall be provided with automatic starting facilities which will be activated for any of the following causes: 

When the fire water ring main pressure is lower than 7 barg at the hydraulically most remote monitor or hydrant



Local manual start (Local control panel)

The fire water ring main pressure was designed to be always maintained by the jockey pump that could start automatically when the fire water header pressure is low (below 7barg) and stop when the fire water header pressure is high (above 7barg). For any reason, if the fire water ring main pressure falls down below 7 barg the duty fire water pump was designed to start automatically. When the duty fire water pump failed to start or not able to develop the required minimum pressure of 7 barg at the most remote point, the standby pump was designed to start automatically.

Pumps can also be started manually from the pump local control panel. The only way for the operator to shutdown the fire pumps would be by pressing the local stop push button. 2.2.6 Looping The fire water network was designed to be laid in closed loops as far as possible to ensure multidirectional flow in the system. Isolation valves were proposed to be provided in the network to enable isolation of any section of the network without affecting the flow in the rest as shown in the attached Plot Plan. The Isolation Valves was proposed to be gate valves made of cast steel. 2.2.7 Criteria for above and underground network The fire water network piping was normally designed to be laid above ground at a height of 300mm above finished ground level. However, the fire water network piping was proposed to be laid below ground level at the following places: 1. Road crossings 2. Places where the above ground piping could likely to cause obstruction to operation and vehicle movement, and get damaged mechanically.

2.2.9 Protection for underground pipelines Where the pipe was laid underground the following protections were proposed to be provided: 1. The pipes would have at least one meter earth cover in an open ground and 1.5 meter earth cover under the road. In case of crane movement areas, pipes would be protected with concrete/steel encasement. 2. The pipes would be internally non-lined and externally coated 3. In case of poor soil conditions it was recommended that concrete supports be provided under the pipe. 2.2.10 Protection for above ground pipelines Where the pipes were laid above ground, the fire water mains should be by the side of road on an independent route. The pipe should not be laid on common route with the process piping.

2.2.11 Sizing of fire water distribution ring main Fire water distribution ring main was sized based on the 120% of the design water rate as shown below: Using the basic pipe flow equation (Q = VA). This equation was converted to normal units of measure, as well as using the inside pipe diameter. The new equation later used was:

Q=2 . 448 × v × d 2

(2.1)

Where: Q = flow rate in gallon per minute v = Maximum velocity for fire water in ft/s d = diameter in inches 850 (4.402) (114.4)

v = 10ft/s, Q = 120% of 530m3/hr = 636m3/hr = 2799.7gpm 2799.7=2.448× 10× d

2

d = 11 in. Selected pipe diameter is 12 in., Schedule 40. Based on NFPA 15 (Section 5.1.3) which states that fire water spray system components shall be rated for the maximum working pressure to which they are exposed, but not less than 175 psi (12.1 bar); Design Pressure (P) of 13bar (188 psi) was selected for this system. 2.2.12 Friction loss calculation in water distribution pipe Pipe friction losses was determined on the basis of the Hazen and Williams formula 4 .52 Q1 .85 p= 1 . 85 4 . 87 C d (2.2)

Where: p = frictional resistance in psi per foot of pipe Q = flow in gpm (gram per minute) C = friction loss coefficient d = actual internal diameter of pipe in inches For the pipe distribution (based on fire water spray system plot plan), a friction loss is calculated as follows: Q = 2799.7 gpm C = 120 d = 12inch 120 ¿ ¿ ¿ 4.52(2799.7)1.85 p= ¿

p = 0.00852psi per foot of pipe.

For 1148ft (350 m) straight pipe, a friction loss is calculated as: 1148×0.00852=9.78 psi

For 4 (four) 900 Standard Elbows each with equivalent pipe size of 27ft, friction loss (p) is calculated as: 27 × 4 ×0.00852=0.92 psi

For 8 gate valves each with equivalent pipe size of 6ft, friction loss (p) is calculated as: 8 ×6 × 0.00852=0.41 psi

For 8 Tee or cross (flow turned 90°) each with equivalent pipe size of 60 ft, friction loss (p) is calculated as: 8 ×60 × 0.00852=4.1 psi

Total friction loss along the pipe network = (9.78+ 0.92 + 0.41+ 4.1) psi = 15.21psi = 1.03bar. 2.2.13 Pipe support Fire water piping was designed to be supported in order to maintain its integrity under fire conditions. Piping was designed to be supported by a concrete bases that will rise up to 300m above the ground at 15ft from each other. 2.2.14 Fire hydrants Fire hydrants were proposed to be provided in the network to ensure protection to all the facilities. The location of the hydrants was carefully decided keeping in view the easy accessibility as shown in the Plot Plan for Fire Water System. Hydrants were designed to be located along road side for easy accessibility as far as possible. 4 (four) number of hydrant is selected for this system based on hazardous area considerations as shown in the Plot Plan for Fire Water System (Appendix 1).

All fire hydrants were proposed to be able to deliver 100% of the fire water requirement (530m3/hr) at its outlet at 7 barg. One fire hydrant was 6in. (150 mm) type with a single hydrant valve. One 4in. (100 mm) and two 2 1/2in. (65 mm) outlets with chained caps. The hydrants would be fed from the fire main.

Other Specification 

Design Pressure :



Material :

13 bar (188 psi)

Body ASTM A 106 Grade-B, Cap ASTM A 105, Chain SUS 304,

Valve B.C.6 

Isolation Valves:

Gate valves made of Cast Steel.

2.2.15 Monitors Monitors was deigned to be located at strategic locations for protection of cluster of filters, heaters, etc. 2 (two) monitors were proposed for the protection of the area. Each of these monitor connections would be provided with independent isolation valves so that the area the monitor is protecting can be isolated from the remainder of the station in case of an emergency. Monitors would be located to direct water on the object as well as to provide water shield to workers approaching a fire. The monitors would not be installed less than15 metres the equipment cluster. Water monitors would have a straight stream range of at least 55 m in still air conditions at the normal water operating pressure with a flow rate 530 m3/hr at 7 barg. Other specification 

Type: Fixed water monitor



Design Pressure: 13 barg (188 psi)



Isolation Valves: Gate valves made of Cast Steel.

2.2.16 Fire Hose Boxes Fire Hose boxes are generally provided for the storage of fire hoses and nozzles to enable easy access during fire emergencies.

Hose boxes (cabinets) were proposed to be located in the fire storage section of the security shed of the PRMS. They are proposed to be manufactured of steel and be of the self standing type, colored red, and have air vents in the side panels and lockable doors with a key in a glass fronted box located on the side of the cabinet itself. They are designed to stand on legs. The base would have a suitable drain hole at its lowest point.

2.3 Problems Encountered The problem encountered during the course of doing the design work and the solution provided were: 

Government bureaucracy which affected the project schedule. This was addressed by



working sometime on Saturday. Hindrance from project host communities to gain access to site. A better community relation approaches was developed to take care of that

2.4 Conclusion The project was meant to select and size the main units of the fire water spray system. The study was also meant to carry out hydraulic calculation for the water distribution network. This objective was met in three phases. The first part involved selection of main units. The second part involved sizing of the units. The third section involved hydraulic calculation for the water distribution network. Conclusively, a fire water spray system was designed based on the “Single Fire Risk” for the PRMS. 2.5 Recommendation 

Additional hydraulic analysis for the water distribution network involving use of simulation software such as PIPENET software suite should be carried out.



Further structural and mechanical engineering design studies to confirm mechanical and structural part of the project should be carried out.

CHAPTER THREE - COMPRESSED NATURAL GAS MOTHER STATION (CNG) ENGINEERING, PROCUREMENT AND CONSTRUCTION (EPC)

3.1 Statement of the problem Oando Gas & Power Limited (OGP) awarded an Engineering, Procurement and Construction (EPC) project to Ener-Gas International Investment Limited to develop Compressed Natural Gas (CNG) Mother Station (CMS) along Oshodi-Apapa Express Way in Lagos for the supply of natural gas through tube trailers to consumers away from the existing gas pipeline network and also for vehicular usage. The expected output capacity of the plant is 150,000 Standard Cubic Meter per Day (SCMD) at a discharge pressure of 250 barg. The plant comprises of the following components: 

6 inches, 100m spur line from the existing 8” dia. main distribution network along Oshodi-Apapa Express Way.

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Gas Inlet filter separator.

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Pressure Regulating and Metering Skids (PRMS) for the CMS and the Power generation units.

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Gas drying unit

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CMS for dispensing to tube trailers and NGV filling

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Power generation system

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Utility systems

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Operator control building

The author was involved in managing the project for a period of four month as a project manager. 3.2 Solution Provided As the project manager, the author performed the following responsibilities:

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Serving as Contractor’s representative to manage project planning, design, procurement, construction and acceptance of work related to the project.

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Identifying and qualifying sub-contractors for the project

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Leading negotiation with sub-contractors

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Reviewing and approving bill of quantities from sub-contractors

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Handling invoicing

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Working with project sub contractors to develop project management plan; maintain scope, time and cost; and review and approve work/deliverables.

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Reviewing test results/certificates of all subcontractors.

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Development and implementation of project quality system.

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Developing and maintaining project communication plan to ensure adequate flow of information among all stakeholders

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Developing project risk management plan, identifying possible risk factors and proposing and executing appropriate mitigation.

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Coordinating project reporting

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Securing necessary approvals required for the project, etc.

3.3 Problems encountered The problem encountered during the course of doing the design work and the solution provided were: 

Failure of the previous project management team to apply sound project management practices to the management of the project activities. This was addressed by re-planning

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from the period the author took over. The new plan was fully deployed for the project. Missing design information which was addressed by engaging fresh design engineers to redesigning the missing design packages.

3.4 Conclusion The major objective of this project was to develop downstream facilities for the supply of natural gas through tube trailers to consumers away from the existing gas pipeline network. This objective was met in three phases. The first part involved successful management of the remaining design phase. The second part involved managing the scheduled construction work for the period. The third section involved successful management of delivery of the procured equipment skid to Nigeria from Italy. 3.5 Recommendation 

Sound project management practices should be deployed at all stages of project lifecycles.

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Comprehensive checklist should be developed at planning stage of project to ensure all work packages are adequately completed at scheduled time.