integrating gis data with pipeline design (part 1)

Integrating PipelineDesign with GIS

Part 1A presentation by Usman Imtiaz

All materials and softwares used in thispresentation is for research andacademic purpose only.

Introduction

This Presentation shows an effort to utilize different geomatics techniques todesign a pipeline over a topography. Integration of GIS data with a pipeline canhelp optimize the pipeline design and reduce overall design related costs. Thispresentation will demonstrate:

1. Using GIS data to laydown the centerline of the pipeline over a topography

2. Generate a plan and a profile of the pipeline

3. Carryout pipeline’s hydraulic analysis once the pipeline layout has beenfinalized

GISDigital Elevation Models

In this approach we have utilized Digital Elevation Models to use as an existingTopography

A digital elevation model (DEM) is a digital model or 3D representation of aterrain's surface.

GISUsing DEMs

The DEM alone does not offers much help. The only way it is helping is byproviding latitude, longitude and elevations. We cannot see any obstructions.Now here is neat technique called georeferencing the DEMs with the a satelliteimage.

GISGeoreferencing DEM

The important thing while downloading DEMs from different GIS softwares is thatit needs to have three things

1. Projection

2. Datum

3. Zone

The above drawing has the following information:

1. Projection: Universal Transverse Mercator

2. Datum: NAD 27

3. Zone: Zone 13, Meter

Without providing the correct projection, datum and zone the DEM is useless.

Pipeline RoutingAlignment

Now we have the data we need to route our pipeline. We have a DEM and thesatellite imagery to carry out pipeline routing.

When we route the pipeline, the software generally creates stationing alongthe pipeline route or alignment. It is important to understand that thisalignment has two aspects:

1. Lattitude (y)

2. Longitude (x)

Both are in meters. This means that we can measure the distance between twopints in the pipeline

Horizontal Distance = ((x2-x1)^2 + (y2-y1)^2)^0.5

This horizontal distance is called the stationing.

Pipeline RoutingAlignment Obstructions

The following pictures show a pipeline route drawn without using satelliteimagery.

Pipeline RoutingAlignment

Now we design the pipeline based on a DEM properly Georeferenced withsatellite imagery.

Pipeline RoutingProfile

Only the latitude and longitude is not enough to design a pipeline. One has tobe aware of the elevation changes in the pipeline. The elevation changes willdetermine how much of civil excavation and backfilling needs to be done. Theelevation will also effect the hydraulics of the pipeline. Hydraulics becomescrucial when dealing with gases which can change phases due to pressure andtemperature changes and due to friction and elevation changes.

The next slide shows the consequences of not taking into account theelevation changes in the pipeline.

Pipeline RoutingProfile

The next slide shows you a proper profile as a result of proper routing.

Pipeline RoutingCenterline

What have we achieved till now is the following:

1. Pipeline Plan

2. Pipeline Profile

What we have extracted form the plan and profile:

1. Centerline

The next slide shows some centerline data. This centerline data is based on theProjection, datum and zone that we have specified before.

Note:

1. North = Latitude

2. East = Longitude

Google Earth Tour

This is the interesting part where we get to see our pipeline in google earth.

(The File can be provided upon demand)

Google Earth required to play the file

Hydraulics Analysis

Now we have all the inputs required to carry out hydraulic analysis of thepipeline. The following case studies shall be carried in the hydraulics software:

1. Case 1: P/T analysis using land profile

2. Case 2: P/T analysis using pipeline profile (Simulator and Manual)

3. Case 3:Pipeline Diameter Sensitivity Analysis

4. Case 4:Affect of Water in Dry Gas

Hydraulics AnalysisCase 1Input Features

Pipe Inside Diameter: 9.5 in Inlet Pressure: 1000 psia

Pipe Thickness: 0.25 in Gas Flow Rate: 2 MMSCFD

Pipe Roughness: 0.001 in Heat Transfer Coefficient: 2 Btu/Hr.F.ft2

Ambient Temperature: 60 F

Single Phase Correlation: Moody

Gas Properties:

Dry Gas

Gas Specific Gravity: 0.71

CO2 Mole Fraction: 0.02

H2S Mole Fraction: 0.04

Hydraulics AnalysisCase 1

Land Profile:


Pressure Profile

Output Pressure: 938.88 psia


Temperature Profile

Output Temperature: 58.9 F

Hydraulics Analysis SimulatorCase 2

Input Features

Pipe Inside Diameter: 9.5 in Inlet Pressure: 1000 psia

Pipe Thickness: 0.25 in Gas Flow Rate: 2 MMSCFD

Pipe Roughness: 0.001 in

Ambient Temperature: 60 F

Single Phase Correlation: Moody

Gas Properties:

Dry Gas

Gas Specific Gravity: 0.71

CO2 Mole Fraction: 0.02

H2S Mole Fraction: 0.04


Pressure Profile

Output Pressure: 945.9281 psia


Temperature Profile

Output Temperature = 59.89 F

Hydraulics Analysis ManualCase 2

Pressure Profile

Outlet Pressure: 952 psia

940

950

960

970

980

990

1000

1010

0 5000 10000 15000 20000 25000

Pressure vs Horizontal DistancePressure - y axis, Distance – x axis


All conditions are the same as mentioned in Case 2 except the inside diameter ofthe pipe.

InsideDiameter

Thickness InletPressure

OutletPressure

MinPressure

InletTemperature

OutletTemperature

in in psia psia psia F F

11.5 0.25 1000 946.08 939.23 80 59.90

9.5 0.25 1000 945.93 939.15 80 59.89

7.5 0.25 1000 945.39 938.84 80 59.87

5.5 0.25 1000 942.55 937.20 80 59.83

3.5 0.25 1000 910.10 910.10 80 59.74


Now we test the pipeline with all conditions stated as in Case 2 but with thefollowing addition:

Inlet Temperature: 450 F

Water to Gas Ratio: 10 STB/MMSCF

Heat Transfer Coefficient: 0.05 Btu/Hr.F.ft2 (Insulated Pipeline)


Pressure Profile

Output Pressure: 829 psia


Temperature Profile

Output Temperature: 67.97 F

End of Part 1