mh-crude export pipeline - src pipe

Specification of Piping and Flowline MH-Crude Export pipeline

Designed and Operating Conditions for Pipeline

Size (Internal Diameter) 6” for Carbon Steel / two pipe of 125 mm ID for SRC OR one pipe of 156 mm ID for SRC

Length 3.8 Km

Material Carbon Steel OR Spoolable Reinforced Fiber Line Pipes

Corrosion Allowance 3 mm for Carbon Steel & NOT APPLICABLE for SRC Pipes

Service Processed Crude Oil

Flange Rating 600 #

Maximum Operating Pressure 35 barg

Maximum Allowable Operating Pressure

35 barg

Designed Pressure 92.7 barg

Hydrotest Pressure 116 Barg

Maximum Operating Temperature 60 °C

Maximum Allowable Operating Temperature

70 °C

Designed Temperature 75 °C / Black Bulb Temperature

Designed Capacity 10000 BPD

Designed Life 10 Years

Pipeline Design Code ASME B31.4 / ISO13703

Approved Vendor list:

1. SOLUFORCE

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2. FIBERSPAR

3. AIRBORNE COMPOSITE TUBULARS B.V.

4. Thermo Flex

Contractor is encouraged to submit the price for any of, or both options of pipeline:

Single 6” ID Carbon Steel underground pipeline. OR

Two parallel pipes of 125 mm ID OR One Pipeline of 156 mm ID of Spoolable Reinforced Polymer underground Pipe

Only one of the above construction material types will be selected by the Company during Commercial Evaluation stage.

1. Pipeline Route

The pipeline shall initiate from Munhamir-1 Well location and shall be tied in to the 10” Shams Export Condensate pipeline at BVS-2. The co-ordinates of Munhamir-1 and BVS-2 is illustrated in below table:

Sl. No.

Location Description Coordinates

Easting Northing

1. Munhamir - 1 366328.13 2571394.03

2. BVS-2 369683.46 2572591.20

PTTEP Oman has performed the site survey and the route for the pipeline is proposed in accordance with drawing No. OS-1522-06 Munhamir -1-BVS-2/1. The drawing has been appended here in Appendix.

The pre-construction survey shall confirm and establish that the proposed route:

The optimum from length, construction and installation point of view. If not, then an alternate route which is more economic in terms of length and constructability shall be proposed to the Company.

Takes full account of the associated risks particularly safety and environmental risks, the accessibility for maintenance and inspection, as well as normal direct cost considerations.

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The pipeline shall have a permanent right of way. The width of ROW shall be 10 m either side from center line of the pipeline.

The radius of curvature of the pipeline foundation along route shall not be less than

500xD, D being the pipeline diameter. Hot bends or field bends shall be used when lower values are necessary. The minimum bend radius shall be confirmed by 1000 hour survival test on the product family representative at the qualification test temperature.

The minimum distance for pipelines installed in a separate trench alongside an existing buried pipeline shall not be less than 2 m. However this distance can be reduced to a safe minimum distance at BVS-2 Where the pipeline is proposed to be tied in with the Existing Condensate Pipeline.

The crossing of existing pipelines, cables, power lines, roads, railways and waterways are at an angle between 60 and 90 degrees.

When installing a pipeline along power lines, the horizontal distance from any of the power cables and posts is at least 10 m for power lines at 110 kv and above, and 4 m for power lines below 110 kv.

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Figure 1 Shams and Munhamir Road Distance

The survey findings as stipulated in the drawing No. OS-1522-06 Munhamir -1-BVS-2/1 shall be verified prior to finalizing the route of the pipeline. Based on the confirmation of survey data, A final route for the pipeline shall be established.

2. Pipeline Crossings

The proposed route of the pipeline is expected to cross the service and graded roads at

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minimum two locations.

The crossings shall be designed using casings for the crossing of roads or railways. The Crossing design shall comply with the requirements API RP 1102 and Amendments /Supplements; if any established during design.

The Road Crossings shall be constructed using most suitable method for the Construction. Directional drilling is particularly suitable for long crossings, e.g. rivers and waterways; the method can achieve large burial depths, and it is insensitive to current, river traffic, etc.

The pipeline at Crossing Location shall comply with cover as well as separation requirements. The recommended minimum covers at crossings can be found in Table below:

Recommended Minimum Cover at the Crossings for Pipeline

Location Minimum cover (m) in Normal ground

(Note 1)

Minimum cover (m) in Rock,

requiring blasting

Class 1 0.8 0.6

Class 2 1.0 0.8

Class 3 and 4 1.2 1.0

Public roads and railways crossings

1.5 1.2

Note: The cover refers to the undisturbed ground level.

It is to be noted that Public Roads does not includes the service roads and graded Roads. Only Road in Location Class 3 & 4 shall be considered as Public Roads.

The pipeline and any other buried structures, e.g. existing pipelines, cables, foundations, etc. shall be installed with a minimum vertical separation of 0.3 m.

It shall be established that the Over burden due to the cover at the crossing location shall not burst the pipe when it is empty and is filled with water & fluid.

3. Wadi’s

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In accordance with Drawing No. OS-1522-06 Munhamir -1-BVS-2/1, there are no wadi’s along the proposed route of the pipeline; However as a result of the verification of the survey data, If any wadi is found, then PTTEP Oman shall provide sufficient historical data from MOG Oman so as to identify the type of wadi’s and accordingly design the pipeline protection.

4. Other Crossings

In accordance with Drawing No. OS-1522-06 Munhamir -1-BVS-2/1, There are no Historical Structures, Monuments, Falaj etc enroute the pipeline; however during verification of the Survey data, it shall be verified.

As a result of the verification of data, If any historical structures, monuments, falaj is found, then either the route of the pipeline shall be deviated suitably to keep the safe distance between these structures and pipeline else a suitable Crossing shall be designed.

5. Survey’s

During Pre-Construction Survey, The survey data shall be verified. The survey data as a minimum shall contain:

Population and building densities for the establishment of location classes, location

of inhabited buildings, taking into account any future land development plans. Topographical data, location of rivers, roads and railways,

including type and density of traffic.

Records of any existing special features which will need reinstatement after construction is completed.

Soil investigation for foundation design (burial and/or supports design), subsidence areas (e.g. due to mining activities).

Soil resistivity for cathodic protection design. Environmental data (climatic, floods, earthquakes, landslides,

currents at river crossings, vegetation, fauna).

Presence of Underground Cables.

6. Proximity to Occupied Buildings

There are no buildings in the Proximity of the proposed route.

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7. Proximity to Other facilities

The requirements of separation between the pipeline (including pig traps) and other facilities within the plant fences or on the offshore platform should be in accordance with Hazardous Area Classification.

8. Sizing

The following pipeline sizes have been found suitable for the designed capacity of 10,000 BPD:

i) 6” Nominal Diameter Carbon steel with internal diameter of 6.125”.ii) 5” Nominal Diameter Spoolable Reinforced Polymer Pipe with internal diameter

of 4.92”. (construction in 2 parallel pipes)

Any change in the either capacity of the pipeline or any of the designed, Process and Operating parameter that has impact on the Pipeline sizing shall warrant revalidation of the pipeline size.

The above established sizes shall be verified / optimized during engineering or prior to finalizing the size of the pipeline.

This shall be done by performing a steady state hydraulic analysis. The roughness of the internal surface of the pipe shall be assumed as below:

2 Microns for Spoolable Reinforced Polymer Pipe

47.5 microns for Carbon Steel Microns

The Fluid Velocity in the pipeline may be limited due to the following concerns:

Pressure Losses

Prevention of Cavitations at pumps and valves

Prevention of transient overloads (water hammer)

Reduction of Erosion and noise

Prevention of Wear in the components such as Valves

Pipe diameter and Geometry

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The Hydraulic Analysis shall take full account of possible changes in flow rates and operational modes, over the complete operational life of the pipeline.

The maximum fluid velocity in the pipeline shall not be more than the superficial velocity in the pipeline (as an extreme case) and shall not be less than the fluid velocity in 10” Shams Export Condensate pipeline at Tie in Point. If the pipeline has been designed for superficial velocity, it shall be established that the pipeline shall not have erosion problem.

For the proposed pipe size, fluid properties and flow rate, the steady state hydraulic analysis shall provide:

The pressure and temperature profiles along the pipeline for steady state conditions.

Data to address: surge pressure during shut-down of a liquid line, liquid catching and slug control requirements at the downstream end of two phase lines.

9. Material Selection

The Pipeline shall be made up of one of the following materials:

Spoolable Reinforced Polymer Pipes

Carbon Steel.

The Line Pipe manufacturer shall design and manufacture these pipes to meet the Project Design requirements and to comply with the Designed and Operating Conditions. The Pipe line made up of these Line pipes shall be suitable to Operate under the Environmental conditions and shall transport the fluid having properties indicated in the Article 3.9 of this document.

The line pipes shall comply with Project Specific Documents, “Specifications of Spoolable Reinforced Fiber Line Pipes.” and “Line Pipe Specifications” appended here to in Appendix 6.

10. Design Life

Pipeline: 10 years.

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11. Location Class

The Pipeline shall be transporting Category B Fluid ( in accordance with ASME B31.8 Article 840.2 There is no specific requirement apart from access requirements during construction and for maintenance and emergency services during operations.

The pipeline route falls under Location Class 1 Div.2. The Strength (SMYS) of the pipe shall be increased in consideration with the Design factor considered at a particular location & wherever required the route selection shall take due regard for the cost impact on pipeline sections in location classes of higher category.

12. Strength Considerations

D/t Ratio

The D/t Ratio requirements shall not exceed:

65 for Spoolable Reinforced Polymer Pipes

96 for Carbon Steel.

The Line Pipe manufacturer shall design the minimum required thickness for the said application and thereby shall establish that the D/t Ration is not detrimental to the construction and in-situ integrity of the pipeline.

Design Factors

The following design factors for the establishing the adequate strength of the pipeline shall be used.

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Design Factor for Pipeline

FLUID CATEGORY A and B

APPLICABLE CODE B31.4 (Note 1)

LOCATION CLASSES 1, 2, 3 and 4

Pipelines 0.72

Crossings (Note 2)Private roads 0.72Unimproved public roads 0.60Roads, highways, streets and railways 0.60Rivers, dunes and beaches 0.60

Parallel encroachments (Note 3)Private roads 0.72Unimproved public roads 0.72Roads, highways, streets and railways 0.72

Fabricated assemblies (Note 4) 0.60

Pipelines on bridges 0.60

Near concentration of people 0.72

Pipelines, within plant fences, block valve stations and pig trap stations (Note 6)

0.60

Note 1: ANSI/ASME B31.4 does not makes any provision for using design factors other than 0.72, which are inappropriate at critical locations (e.g. crossings, within plant fences), and for fabricated assemblies. In such conditions, design factors in accordance with ANSI/ASME B31.8 location Class 1 shall be used.

Note 2: ANSI/ASME B31.8 differentiates crossings with casings and without casings. Because of the poor experience of cased crossings (i.e. annular corrosion), the same design factor is recommended, whether a casing is used or not. Design factors for crossings of rivers, dunes and beaches, not included in ANSI/ASME B31.8, are provided.

Note 3: Parallel encroachments are defined as those sections of a pipeline running parallel to existing roads or railways, at a distance less than 50 metres.

Note 4: Fabricated assemblies include pig traps, valve stations, headers, finger type slug catchers, etc.

Note 5: Concentrations of people are defined in ANSI/ASME B31.8 Article 840.3.

Note 6: This category, not specifically covered in ANSI/ASME B31.8, is added for increased safety.

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Equivalent StressesThe wall thickness for pipeline made up of Carbon Steel, derived from hoop stress considerations based on design factors indicated above, should be such that the longitudinal, shear, and equivalent stresses in the pipe wall under functional and environmental loads do not exceed by 96% during Installation, 100% during Hydrotest and 90% for Operational Load Case.

• Two types of load shall be considered:a) Functional loads (defined in Article A841.32).b) Environmental loads (defined in Article A841.33).

• The equivalent stress shall be defined as follows:

Seq= (Sh2 + SL 2- ShSL+ 3Ss2)1/2 (Von Mises equation)

Where as; Seq = equivalent stress

Sh = hoop stress (due to pressure)

SL = longitudinal stress (due to pressure, thermal expansion and

bending)Ss = combined shear stress (due to torque and shear force)

There are three types of stresses to be considered in the calculation of the equivalent stress: the hoop stress, the longitudinal stress and the combined shear stress.

Hoop stress:

Longitudinal stress:

Fully restrained pipeline:

SL = (Sh - P) - E (T2 - T1)

Fully unrestrained pipeline:

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Combined shear stress:

P = pipeline internal pressure,D = pipeline diameter,t = wall thickness, = Poisson's ratio,E = modulus of elasticity, = linear coefficient of thermal expansion,T1 = pipeline installation temperature,

T2 = pipeline operation temperature,

Mb = bending moment applied to the pipeline,

Z = pipe section modulus,T = torque applied to the pipeline,Fs = shear force applied to the pipeline,

A = pipe wall cross section area,

The equivalent stress shall in all cases be less than 72% of SMYS.

The design of Spoolable reinforced polymer pipes shall comply with the requirements of API15S or API17J. The Line pipes shall comply further with the stress requirements as indicated above for Carbon Steel.

13. Thickness Calculation

The Wall thickness of pipe(s), either made up of Carbon Steel line or of Spoolable reinforced polymer pipes, the pipes shall satisfy the following:

D/t Ratio requirements cited in this Section.

Pressure Containment

Equivalent Stresses

Installation Stresses due to Overburden

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14. Corrosion

For Spoolable reinforced Polymer Pipes:

The line pipes do not contain steel; thereby no Corrosion phenomenon takes place. This covers Internal as well as external Corrosion. There by no provision of Corrosion Monitoring, Corrosion Protection in any form is envisaged.

1.1.1 a) Internal

The internal Pipe surface does not contain Steel in any form thereby no Internal Corrosion can take place.

1.1.2 b) External

The external Pipe surface does not contain Steel in any form thereby no External Corrosion can take place.

For Carbon Steel Line Pipes:

The Pipeline shall be protected for Internal Corrosion by providing 3 mm Corrosion allowance. This Corrosion Allowance is in accordance with PTTEP Guidelines.

The pipeline shall have continuous Internal coating for flow enhancement. No Chemical Injection has been envisaged during the entire designed life. The Coating condition and the possible Internal Corrosion of the pipeline shall be monitored by: E/R Probes

Weight Loss Corrosion Coupons

Iron Count Analysis

Pipeline design & Layout shall make the required provisions at both ends of the pipeline.External Corrosion of the pipeline shall be mitigated either by using the 0.5 mm thick FBE.

The above External Anti Corrosion Coating shall be supplemented with Cathodic Protection System. Contractor shall design a suitable Impressed Current Cathodic Protection System for this pipeline.

15. Pipeline Installation

The Pipeline shall be installed in accordance with Project Specific document “Pipeline Construction Specifications” (see Appendix 7).

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Burial Philosophy / Pipeline ProtectionThe pipeline if made up of Carbon Steel shall be buried to protect it from mechanical damage, fires and tampering. The recommended minimum covers are given in the below Table:

Recommended Minimum Cover for Onshore Pipeline

Location Minimum cover (m) in Normal ground(Note 1)

Minimum cover (m) in Rock, requiring blasting

Class 1 0.8 0.6Class 2 1.0 0.8Class 3 and 4 1.2 1.0

Public roads and railways crossings

1.5 1.2

NOTE 1: The cover refers to the undisturbed ground level.

Recommended Minimum Cover for Onshore Pipeline Made Up of Spoolable Reinforced Polymer Pipe

Location Minimum cover (m) in Normal ground(Note 1)

Minimum cover (m) in Rock, requiring blasting

Class 1 0.8 0.6Class 2 0.8 0.6Class 3 and 4 1.0 0.8

Service and Graded Roads

1.0 0.8

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In determining depth cover in agricultural areas, the depth of ploughing and of drain systems shall be considered. A cover of 1 m would be adequate in most cases. In grazing land, where fencing activities are common, a depth cover of 0.8 m is in general adequate.

The pipeline shall be protected by Installing Windrows along the route.

The location of buried pipelines shall be clearly identified by markers. In areas where the risk of interference by mechanical excavators is high, a warning tape should be installed in the excavation above the pipeline to further lower the risk.

16. Overpressure Protection

Maximum allowable pipeline pressures

The pipeline shall be protected against over pressurization. Following shall be considered while designing the overpressure protection system: Maximum Allowable Operating Pressure (MAOP), shall not exceed at any point along the pipeline during normal continuous operations. Maximum Allowable Incidental Pressure (MAIP), shall not be exceeded at any point along the pipeline during upset conditions, i.e. conditions of limited frequency and duration.

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Over pressurization by the upstream facility

The design of Overpressure Protection system shall ensure that in case of the pressure immediately upstream of the pipeline is in excess of the evacuation requirements, the pipeline may be designed to operate at lower pressures. In such case a pressure control system shall be installed to limit the pipeline inlet pressure. However, any type of pressure control system shall not be considered as an overpressure protection system.

When, following failure of the pressure control system, the maximum pressure which may be generated by the upstream facility is such that it results in pipeline pressures in excess of MAIP, an overpressure protection system shall be fitted between the upstream facility and the pipeline. Two methods can be considered:

• A system with pressure relief, consisting of mechanical safety/relief valves.

• An instrumented system with a high reliability for the isolation of the pressure

source from the pipeline in case of overpressure (HIPS).

17. Surge Pressures

The pipeline system shall be designed such that surge pressures does not exceed MAIP at any point along the pipeline, and will not trigger the system for overpressure protection from the upstream facility if fitted.

Methods of preventing the generation of unacceptably high surge pressures including valve closure speed reduction or special fast-response pressure relief systems close to the point of surge initiation. If not sufficient, strict adherence to well formulated operating procedures should be implemented.

18. Thermal Effects

The pipeline system shall be designed such that pressures generated by thermal effects do not exceed MAIP at any point along the pipeline, and will not trigger the system for overpressure protection from the upstream facility if fitted. When those pressures are part of the routine operation of the pipeline, i.e. they occur a significant portion of the time, they shall not exceed MAOP.

The protection against overpressure due to thermal effects may be effected by applying relief valves. Except on assemblies which can be isolated such as pig trap systems and

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slug catchers, an isolation valve may be installed between the pipeline and the relief valve for maintenance purposes, provided that procedural controls are in place to ensure that the isolation valve remains normally in the open position, and that the pipeline is not shut in while the relief valve is out of service.

19. Pipeline Tie-In

The pipeline shall be tied in to the Condensate pipeline at BVS-2. The piping arrangement at BVS-2 is shown in Figure 8.

Figure 2 Pipeline Tie-In Point

A fanged end concentric reducer shall be utilized to connect the pipeline to the existing 8” Flange provided for the Future Connections. Pipeline shall be terminated at BVS-2 with ITAG Pig Valve.

Contractor shall propose the adequate Tie in Arrangement at BVS-2 which will be approved by PTTEP Oman.

20. Safety Risk Assessment

As the pipeline does not passes Location Class 3 and 4 No formal quantitative risk assessment (QRA) is required.

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TIE – IN FLANGE

The risk depends on the expected frequency of failure, external loading, material or construction defects, and operational mishaps. The risks also depends on the consequences of the failure, based on the nature of the fluid in terms of flammability, stability, toxicity and polluting effect, the location of the pipeline in terms of ignition sources, population densities and proximity to occupied buildings, and the prevailing climatic conditions.

The expected frequency of failure and the possible consequences may be time-dependent and shall be analyzed over the entire life of the pipeline.

Risks levels shall be reduced by using lower design factors (e.g. higher wall thickness or stronger steel), rerouting, providing additional protection to the pipeline, application of facilities to minimize any released fluid volumes, and controlled methods of operation, maintenance and inspection.

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