GIS for Construction and Rehabilitation of Oil and Gas Pipelines

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GIS for Construction and Rehabilitation ofNigerian Oil and Gas Pipeline Routes

Adewumi Rowland, MSchttp://www.rowland-adewumi.com

The Nigerian Oil and Gas 2007


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ABSTRACT

This paper will show how Geographical Information System (GIS) decision process can be use to

locate oil and gas pipeline route as an elements of a sound decision making strategy. It will

consider possible use by decision makers and environmental management personnel to analyse

different alternative options in the selection of a cost effective and environmentally friendly

pipeline routes. Multicriteria Decision Analysis (MCDA) is integrated with Geographical

Information System (GIS). In ArcView 9.1 all data are stored and the criterion values and factor

map are generated for all crit eria as map layers. The criterion maps are converted into grids and

mathematical processes are applied to the criteria using Pairwise Com parison Method(PCM) to

calculate the weights. Composite maps are created using Ordered Weighted Averaging (OWA)

Method. Also, this paper propose pipeline operators with a management sy stem based up on

remote satellite surveillance, and a GIS application that is capable of minimising

potential pipeline damage. In addition, a GIS system enables accurate feature

identification and leads to reliable hazard extraction and improvements in system

response time.

INTRODUCTION

Terrorist forces have captured Warri Pipeline pump station at grid NG4545698 with the

intent of creating an environmental disaster. Mission: squad will se ize and accomplish

one of the following: secure the main control panel; stop the flow of oil into the pumps at

the all valve controls, and maximise damage to oi l storage containers and pipelines, and

kidnap expatriate!. Enemy consists of a squad-sized Niger-Delta terrorist force inside the

main pump station. Nigerian Navy troops consisting of one infantry squad from 2nd

Battalion, 1st Infantry Regiment, 72d Sep. Infantry Brigade is ordered to minimise

damage to oil storage containers and pipelines in the region. M ission: silence the squad-

sized Niger-Delta terrorist force No, this is not a Film Review! It is though, a comment

upon the manner in which our oil and gas sector might gravely deteriorate to as a result

of the fruitless efforts been implemented to address the problems.

In Nigeria, conventional oil and gas pipeline route selection models are usually focued on the

economic optimisation with cost minimisation being the sole objective disregarding potential

adverse environmental, physical, political and social impacts. Geographical Information System


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(GIS) has been widely accepted for the exploration of oil and gas in todays multi-billion pounds

oil business, when geoscientists, engineers, and geologist look for oil they plan and implement

GI S. Malczewski (1999) defines GIS as a decision making tool using different data from various

sources for route and site selection problems through spatial analysis and modelling. Much

research has already been performed in GIS route selection projects for the petroleum industry.

Hicken and Krumbach (1998) uses high-resolution remote sensing images in pipeline route

design. GI S was used for the select ion of best route for pipeline expansion (Montemurro and

Gale, 1996). In addition , Sarkka and Esko (1999), in a pipeline route design project uses GI S for

opt imal routing for pipeline network.

In his review, Laura (1998) states that before Oil and gas companies perform bathymetric and

deep-sea surveys, they overlay information about all modes of transportat ion network, topo logy,

previous surveys for the area and environmental sensitive areas. All companies that drill all over

the world must meet certain pre defined environmental conditions and requirement of their host

countries so as to interfere with the communities fragile resources as lit t le as possible. T his

however, is less obvious based in the Nigerian context.

However, despite the need for the recognition of good oil and gas transportation and its

significant contribution to our economy, the management, planning, construction and

rehabilitation of our networks are been still marred by utilitarian and insensitive political,

environmental, and physical consideration. Daily fresh wave of attack are being launched

on oil facilities in Nigeria as unidentified people attacked and set fire to petroleum

pipelines and vandalise pipeline networks. The country has thus become a scene of a

series of pipeline explosions. The massive environmental problems, socio-economic

dislocations and loss of human lives that accompany every pipeline burst in the country

only further worsened the already precarious condition of the masses as they pollute the

environment causing irredeemable distortions to the ecosystem.

Pipeline disasters in the Niger Delta, like the widely televised 1998 Jesse incident, where over

one thousand (1000) community folks were out-rightly incinerated alive in a pipeline products

explosion calls for a multicriteria decision consideration in providing a sustainable solution. In

July 2000, a pipeline explosion outside the city of Warri caused the death of 250 people. An

explosion in Lagos in Decem ber 2000 killed at least 60 people. Recently, no fewer than 40

residents were also injured and many more fainted after an oil pipeline busted in Oke-Odo area of


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Lagos on Monday 3rd

April 2006. The situation left t he environment filled with heavy toxic smell

and gas. Soil erosion of pipeline route, direct vandalisation of pipeline and negligence have been

cont roversially reported as the primary cause (Yakubu et al., 2006).

AIM AND OBJECTIVESThe aim of this project is t o locate the best pipeline routes using GI S multi-criteria decision-

making process by considering basic, physical, environmental, political and economic constraints

for vo latile oil and gas producing region of the country.

The overall object ives of this project are as fo llows:

(i) Evaluate the environmental, economic, physical, political and basic factorsof locating pipeline route using GIS multi-criteria decision analysis

(ii) To use GIS spatial decision-thinking process to model alternativespipeline routes for selected optimum routes on a network.

(iii) To develop a decision support system by evaluating contribut ions andopinion collected and collated from individual and policy makers using

questionnaire.

(iv) To carry out a condition survey of the pipeline routes and a comprehensiveroute evaluation of the pipelines using a GIS database

(v)

To identify and map failures and prepare engineering design and detailsfor the pipe reconstruction, strengthening and protection.

METHODOLOGY

Multicriteria Decision Analysis (MCDA) is integrated with Geographical Information System

(GIS). Primary survey was implemented using questionnaires to secure the participation of the

civil society for the development of weight to prioritise the criteria. Policy makers opinion on

pipeline development in their region and identification of preferred criteria for pipeline networks

and facility were sourced..


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Figure 1: Multi-Criteria Decision-Thinking Process in Route Selection

Landsat satellite imagery, land use cover maps, roads, oil field, railways ArcGIS shape files were

obtained and prepared in a GIS ready format and used as input into the GIS geodatabase. Banai et

al. [9] site-suitability problem evaluation using pairwise comparison method was adopted in the

analysis for this study. The criteria for the project were assessed for relative importance

considering th is method. Two major steps were adopted, generating pairwise and comput ing

criterion weights [5].

In summary, considerations adopted in this research t o route the most optimum route are: (1)

Distance from urban areas, and (2) distance from ecological and coastal erosion prone areas, (3)

distance from airports, (4) distance from reserves and regional recreation lands of the Niger Delta,

(5) distance from political and resistive -zones, and (6) distance from railways, (7) distance from

road, and (8) proximity to exist ing exploration and refining companies. T he first seven criteria are

to be maximised. That is, the farther the route from each of this criterion the better. The last one is

minimisation that requires the pipeline route to be closer to these criteria. Each of the above

criterions is represented as a map layer or criterion map (Table-3). Analyt ical Hierarchy Process

(AHP) was applied in choosing optimal weights for the criteria. This enables criteria alternatives

to be compared.

In ArcView 9.1 software, all data are stored and the criterion values and factor map are generated

for all criteria as map layers. The criterion maps are converted into grids and mathematical

processes are applied to the criteria using Pairwise Comparison Method(PCM) to calculate the

weights. Composite maps are created using Ordered Weighted Averaging (OWA) Method. A

suitability map was thus generated pipeline routes. Specific to the study area, political and

environmental constraints are of the most utmost consideration in locating oil and gas pipeline.


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Therefore, it was considered that distance from towns/cities is moderate to strong importance

preferred over distance to airports; hence the comparison results in a value of 4 (Table-1).

Furthermore, knowing that distance from towns/cities is equal to moderate importance to

distance from railway lines, and then from Table-1 above, this equals a numeric score of 2.

Thereafter, assuming that same distance from towns/cities is of strong importance compared to

proximity to refineries, this equals 5 in the numeric scale. Same scenarios are recorded for all the

crit eria (Table-1). Remaining entries are computed and entered correspondingly.

Figure 2: Weight comparison chart, showing scale of priority

Using Malczewiskis [5] concept, this step invo lves, (a) summing values in each column of the

matrix; (b) divide each element in the matrix by its column total; and (c) calculating the average

of all elements in each row of (b) above, and dividing the sum scores for each row by 9- the

numbers of criteria (T able-1 and Table-3).

REHABILITATION OF OIL AND GAS PIPELINES

Inadequate regular maintenance of the oil and gas pipelines have resulted in enormous

lost of thousands of barrels of oil. Most pipelines presently running in the country are

obsolete, some of which are over 25 years old, making them subject to corrosion and

leakage. In addition, pipelines are laid above ground level without adequate routine

inspection and supervision. This procedure allows for encroachment into the right-of-way

of the pipelines and inevitable exposure to wear-and-tear (Oyem, 2001).

Petroterrorism in form of saboteurs, vandals, aggrieve-politicians, and unemployment are

major cause of oil and gas spillage from pipeline routes in the country. Oil and gas


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pipeline are deliberately damaged and ruined to settle political and economic difference,

while pirates steals the oil sell it illegally on the national and international black market.

This illegal siphoning as resulted in a number of catastrophic oil pipeline explosions in

the country. The recent been the Lagos pipeline explosion where about 700 people

(reported, unreported and the missing), includin g a baby believed to be two months old,

were roasted to death in a pipeline fire on the Lagos-Abeokuta Expressway. The NNPC

reported over 2000 cases of pipeline vandalization in 2005 alone as against mere 800

cases five years ago. Nigeria lost about N43 billion in 2005 as a result of vandalisation of

pipelines carrying petroleum products.

The most common measure against this form ofpetroterrorism is by observing the

pipeline by either wa lking along the routes and by using helicopters guided by electronic

maps (GIS) and satellite navigation (GPS) for the pipeline network. Whilst in few cases,

digital pictures or videos are taken. One of the most efficient ways forward is the

development and design ofpipeway-system. Oil and gas pipeline routes criss-crossing the

entire country could be monitored for adequate emergency response and rehabilitation

using high-resolution satellite images, GPS and GIS technology. High r esolution satellite

images should be acquired for the oil and gas pipelines network for rehabilitation. Images

are orthorectified and used in determining horizontal alignment of the existing pipelines.

Digital Elevation M odels (DEM ) should be first developed and high resolution images

orthorectified using the DEM and ground control points collected by GPS. A typical

rehabilitation pipeline project will involved building a GIS database for all related

pipeline facilities and infrastructure along a typical route. Buildings and adjoining

pipeline furnitures can digitized from high-resolution satellite images and a geocoding

system developed.

CONSTRUCTION OF OIL AND GAS PIPELIN ES AVOID VANDALIS ATION

The steel used in the construction of pipelines should be thick above the minimum

requirements as specified by acceptable codes in Nigeria, so a very large explosion will

be required to puncture p ipelines. M aintenance culture in Nigeria is alway s inadequate. It

is a system ofBuilt-Operate-Build (BOB). Therefore, corrosion risk should be addressed


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GIS for Construction and Rehabilitation of Oil and Gas Pipelines

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