1. GEOMATICS BEST PRACTICES IN SAKA INDONESIA PANGKAH LIMITED (CASE
STUDY: UJUNG PANGKAH PIPELINE INTEGRITY)
Authors:
Yudi Syahnur – Geomatics Coordinator, Saka Indonesia Pangkah Ltd
Khostarosa Andhika Jaya – Operations Manager, Saka Indonesia Pangkah Ltd
Abstract
Pangkah Block PSC is located in Offshore East Java. It’s a highly sensitive area due to massive
fishing activity on and around 700 square kilometer area, as well as thousand hectares of fishpond
located adjacent to the south of block’s boundary.
Ujung Pangkah Field is the only producing field in Pangkah PSC block so far, located in active
delta branches of the Bengawan Solo River. Large amounts of sediment materials are being
transported from the land outflow to the sea by the Bengawan Solo River. It is estimated Bengawan
Solo river delta has a huge mud sedimentation flow that deposited 17 million tons of mud per year.
Operating in such harsh condition, Pipeline Integrity in Ujung Pangkah is critical to company’s
success. Loss of pipeline integrity can result in leaks of crude oil or natural gas, which can
negatively impact the safety of community, environment, and Pangkah Field operability. Pipeline
integrity should be maintained through proper design, proper installation and robust maintenance
program that consist of proper monitoring, proper inspection and proper intervention when
required.
Geomatics can be described as science and technology to collect, process, manage, analyze and
display geospatial data and information. It includes the tools and techniques used in land and
marine surveying, remote sensing, cartography, geographic information systems (GIS), global
navigation satellite systems (GPS, GLONASS, Galileo, Compass). Geomatics have played an
important role to promote Pipeline Integrity in Saka Indonesia Pangkah Limited (SIPL).
This paper will describe how seabed stability and geomorphology survey helped SIPL operation
team finding the root caused of 6” Gas Injection Pipeline Rupture in April 2011. The use of
Geographic Information System, High Resolution Satellite Imagery and Intelligent Pigging data
to identify and monitor construction activities around 20” Sales Gas Pipeline from OPF to PLN
will also be discussed.

2. Introduction
Scientific term of Geomatics is defined and proposed for the first time by Michel Paradis, in an
article published by Canadian Surveyor in 1981. It can be described as science and technology to
collect, process, manage, analyze and display geospatial data and information. It is estimated that
more than 90% data and information used in Energy Sector is spatially referenced or pertaining to
specific geographic location.
Oil and Gas industry considered as early adopter of Geomatics, which rapid progress and increased
visibility has been made possible by advances in computer hardware, computer science, and
software engineering. Since 1990's Oil and Gas companies have been using Global Positioning
System to improve land and marine seismic acquisitions process, as well as airborne and space
observation remote sensing technologies to effectively find hydrocarbon prospects. Up until now,
more and more oil and gas companies use Geographic Information System to help extracting
hydrocarbon in a more efficient manner.
Geomatics includes the tools and techniques used in land and marine surveying, remote sensing,
cartography, geographic information systems (GIS), and global navigation satellite systems (GPS,
GLONASS, Galileo, Compass). The use of these tools and technologies in Saka Indonesia
Pangkah Limited (SIPL) have been well established. Comprised from Exploration activities,
Drilling preparation, Field Development to Operation and Maintenance, Geomatics have played
small but important contribution to company’s success so far.
One of the notable application of Geomatics’ marine surveying techniques was shown during
identification of plausible root cause(s) for the 2011 rupture of a 6 inch Gas injection pipeline in
September 2011, in vicinity of Ujung Pangkah field. The infield pipeline connects existing
platforms WHP-A and WHP-B, surpassing a sedimentologically active subaqueous ‘branch’ of
the Ujung Pangkah Delta formed at the mouth of the Bengawan Solo River in Eastern Java. (Figure
1). Further investigations on site (excavation, visual inspection by divers and recovery of ruptured
section) indicated that the line was ruptured at a distance of approx. 1.4 km from platform WHP-
B.
Pipeline Integrity means that the pipeline and all its related components are running properly.
When pipelines are not operating properly, it poses a risk to public safety as well as company
employees and other workers. Loss of pipeline integrity can result in leaks of crude oil or natural
gas, which can negatively impact the public and the natural environment. (Canadian Energy
Pipeline Association, CEPA, 2014). Maintaining Pipeline Integrity requiring proper design, proper
installation and robust maintenance program.
Design phase had been considered critical, where pipeline routes are chosen to minimize potential
negative impacts in the future. It should be based on detailed bathymetry map and seabed stability
survey, which can be obtained from marine surveying using multibeam echosounder.
By comparing multi-temporal marine survey result (2008 and 2012 data), SIPL’s Operation team
gaining valuable knowledge about the character of subaqueous delta between WHP-A and WHP-

3. B. The area is subject to frequent mud flows forming a system of gullies and lobes. Sediment-
laden flows relevant to the area involve pulsed mudflows caused by submarine slope failures and
sustained turbidity flows caused by suspended sediment delivery from the Bengawan Solo River
system (Fugro GeoConsulting Belgium, 2012). This knowledge will also be useful to evaluate the
proposed design of pipeline replacement to connect gas lift from platform WHP B to WHP A.
Maintenance program should include monitoring activities on and around pipelines, including
social activity driven by economic growth of Ujung Pangkah and Gresik region. Problem was arise
in 2014 when part of SIPL’s 9 kilometers long 20” Offshore Sales Gas Pipeline from OPF to PLN
was being subject to reclamation activity by local petrochemical firm (Figure 2).
SIPL’s Operations team reacted quickly by installing above-ground warning signs to clearly mark
estimated pipeline rights of way to avoid worst possibility of active gas pipeline being piled by
construction activities. Next task was to coordinate with Geomatics Group based in Jakarta to
conduct land survey using Geo Penetrating Radar (GPR) technique to accurately locate the newly
buried “Onshore” Sales Gas Pipeline to determine definitive right of way for the 1.40 km segment
pipeline. The exact location of 20” Sales Gas Pipeline from OPF to PLN will be used as technical
reference for further Right of Way definition with external stakeholders.
Method
Marine surveying method using side scan sonar, sub-bottom profiler, multi beam echosounder
(MBES) and single beam echosounder (SBES) was applied to capture seabed stability and
geomorphology conditions at Ujung Pangkah site. The survey was done in 2008 and 2012 by PT
Fugro Indonesia, using dedicated survey vessel equipped with differential global positioning
system (DGPS).
The site covers an area of seabed at between water depths of approximately 1 m and 30 m reduced
to Lowest Astronomical Tide (LAT). The extent of 2008 and 2012 surveys is shown in Figure 3.
The MBES bathymetric data is resolute to a 1 m grid and covers the main delta front only, with
acquisition of bathymetric data on the shallow delta shelf (less than 5 m bLAT water depth) carried
out using low resolution SBES.
Spatial analysis (overlay and subtraction) then applied to the high resolution gridded bathymetric
data of 2008 and 2012, resulting new gridded information of net sediment deposition as result of
seabed changes from 2008 to 2012 as describe in Figure 3.
Land surveying technique using DGPS equipment, total station and GPR sensor was applied to
determine exact location of buried 20” Sales Gas Pipeline (Figure 4). Along with Intelligent
Pigging Data, a recent high resolution World View Imagery, and relevant CAD drawing from
surrounding firms, the result was subsequently plotted on a map. These critical information will
be used for further Right of Way definition with local petrochemical firm and other external
stakeholders around the Sales Gas Pipeline.

4. A web-based Geographic Information System (GIS) was then used to visualize all relevant data
gained from the above marine and land surveying activities. This tools was intended to be single
source of information within SIPL internal stakeholder, and then used as technical reference for
Ujung Pangkah Pipeline Integrity activities such as design and maintenance.
Result
Based on measured bathymetric data, the deltaic morphology between WHP B and WHP A is split
into four zones as defined in Figure 5.
2D image of 2012 combined MBES-SBES bathymetry color-coded according to seabed changes
from 2008 to 2012, showing areas of net sediment deposition (green to yellow to red) and erosion
(light to dark blue). The color map shows deposition thickness in meters. Existing and proposed
pipeline routes are overlaid as black lines with markers at Kilometer Posts. Location of the 6”line
rupture at KP 1.4 is indicated as a black arrow (Figure 6).
The present-day seabed morphology of the site is dominated by the submarine delta that is
prograding northward in a semi-radial manner at a rapid rate. In the shallowest section of the site
(approximately 1.0 m to 5.0 m LAT), the Delta Shelf is present as an apparently flat, featureless
subaqueous plateau, defined by the slope break and incision of gullies at its northern periphery
where the pro-delta begins. The slope of the pro-delta is gentle with an average slope gradient of
1.0° to 2.0° encompassing water depths down to approximately 30.0 m LAT where a transition is
seen to the flat and mostly featureless outer delta.
Between water depths of approximately 5 m and 15 m LAT, the pro-delta is apparently incised by
six main gullies up to approximately 100.0 m wide and 3.0 m deep. Between water depths of
approximately 15.0 m and 30.0 m LAT, many overlapping depositional sediment lobes are
observed with relatively flat tops and steep angled sides. In between the gullies and lobes (Figure
7), areas of relatively smooth and flat seabed are present.
Thalwegs of the various gullies have been mapped (Figure 8). A typical longitudinal profile along
gully 3 (Figure 9, top-left panel) highlights a succession of relatively flat gully bases separated by
short but steep steps in elevation, which are considered remnants of past failure events. The
corresponding cross-sectional profiles (shown in Figure 9, other panels) highlight three stages of
gully development: the upper regions of the gullies (cross-section 3a) show a negative relief
(relative incision) with respect to the inter-gully areas; the middle regions of gullies (cross-section
3b) also show a negative relief, but feature ribbons of positive relief on both side of the gully,
characteristic of levees emplaced by mudflows overflowing the main gully and depositing
sediments on the sides. The lower portions of the gullies (cross-section 3c) are associated with flat-
topped depositional lobes emplaced by freezing of the decelerating mudflows

5. The size of individual lobes varies substantially. Average surface area of individual lobes varies
in the range of 11,000 to 48,000 m². Individual volumes averaged over each gully system are in
the range of 42,000 to 131,000 m³. This corresponds to an average lobe deposit thickness in the
order of 2 to 4 m (Table 1).
Exact location plot of buried 20” Sales Gas Pipeline overlayed with Intelligent Pigging Data, a
recent high resolution World View Imagery, and relevant CAD drawing of surrounding area is
presented in Figure 10. This web-based GIS application is published and accessible throughout
SIPL intranet.
Conclusion
The assessment of the geomorphological conditions at the Ujung Pangkah site highlights the large
mobility of seabed sediment over the region of gullies and lobes, with a high level of activity
observed within the inter survey period from 2008 to 2012. This fact confirming that the observed
morphological features are associated with relatively frequent events occurring at present. The
main conditioning and triggering factors for the slope instability that give rise to the slope failures
is the rapid sediment accumulation rate across the delta, resulting in oversteepening and
underconsolidation of very soft clay sediments.
The proposed route for the new line, which is shown to cross several active gullies near a region
where they may be most active, is consequently considered highly risky in terms of geohazards.
Rather than ultradeep (>5m) trenching which might be considered unpractical, alternative
solutions for risk reduction strategies of the new line should consider rerouting.
Two rerouting options that are considered worth a more detailed analysis, i.e. (1) rerouting to the
North in deeper areas not subject to gully and lobe activity, (2) rerouting to the very shallow shelf
area which is associated with milder seabed gradients and is not subject to gully incision. SIPL’s
Operation team exercised the 1st
option. The replacement pipeline have been built and operate
safely since November 2012 (Figure 11).
Pipeline integrity fails can result in leaks of crude oil or natural gas, which can negatively impact
natural environment, public safety and company’s reputation. Harsh seabed condition combined
with massive construction activities above certain segment pose a real threat to Ujung Pangkah
pipeline operability. Implementation of good Geomatics practices provide SIPL with better data
to promote design and monitoring of Ujung Pangkah pipeline integrity.

6. REFERENCES
Canadian Energy Pipeline Association, 2014. Available at: http://www.cepa.com/about-
pipelines/maintaining-safe-pipelines/pipeline-integrity (accessed 28 November 2014)
FUGRO GEOCONSULTING BELGIUM, 20012. 6”OD Gas Injection Pipeline Rupture Study,
Ujung Pangkah, Indonesia. Report Number: C811, Dated 29th
June 2012. Not Published.
Paradis, Michel. 1981. "De l'arpentage à la géomatique". Le géomètre Canadien 35 (3): 262.
PT FUGRO INDONESIA, 2012. Seabed Stability and Geomorphology Survey at Ujung Pangkah
Block, East Java Sea, Indonesia. Report Number: S2747, Dated 29th
August 2012. Not Published.
PT FUGRO INDONESIA, 2008. Survey for Infield Flowline Routing From Proposed WHP-B
Platform to Existing WHP-A Platform. Report Number: S2061-01 (03), Dated 21st July 2008. Not
Published.
PT MUSTIKA PARUH ANGGANG, 2014. Sales Gas Pipeline (SGP) As-Built Survey. Report
Number: P083-SAE-GPR-MPA, Dated 4th
December 2014. Not Published.

7. Figures and Table
Figure 1.

8. Figure 2.

9. Figure 3.

10. Figure 4.

11. Figure 5

12. Figure 6

13. Figure 7

14. Figure 8
Figure 9

15. Table 1.

16. Figure 10

17. Figure 11.