Intelligent Pigging Inspection of SNEPCO’s Deepwater Production Loop – Bonga, Nigeria
Shell Nigeria Exploration & Production Co. Introduction to SNEPCO
Shell Nigeria Exploration and Production Company (SNEPCO), based in Lagos carries out deepwater projects and operations in Nigeria
SNEPCO operates Bonga; Nigeria’s first deepwater development which has been on stream since Nov 2005
SNEPCO operates Bonga on behalf of The Nigerian National Petroleum Corporation (NNPC) who represent the Nigerian government,
Other co-venturers are ExxonMobil, Total and Eni (Affiliates)
Shell Nigeria Exploration & Production Co. 2 Introduction to Bonga Field
Bonga is Shell’s first and only operated Deepwater asset in Nigeria
Located South West of Warri,120 KM offshore in water depths1000 meters plus
Developed using subsea wells tied to a series of manifolds and tied back to a moored FPSO located centrally in the field
Production is via 4 Production Loops with 8 Steel Catenary Risers (SCR)
Water injection (for pressure maintenance) is via 3 flowlines with 2 SCR’s
Associated Gas is exported via a 90 KM subsea pipeline
Oil is loaded to visiting tankers via a Single Point Mooring located approx 3 KM from the FPSO
Bonga FPSO has capacity >200 kbopd of oil, 100 kbwpd of produced water, 330 kbwpd of injection water and 150 mmscf/d of gas
Shell Nigeria Exploration & Production Co. 3
Bonga Production Manifold (PM) 05 Overview
N
West East
Pigging Loop
Wells
Bonga FPSO Bonga
Production Flowline - 02 Launchers PM5 & Receivers
Production Flowline - 01
Wells
Shell Nigeria Exploration & Production Co. 4 Case for Pigging of Bonga Flowlines
Intelligent Pigging is the only available technology for complete inspection of pipelines from launcher to receiver
Shell as a prudent operator uses IP to confirm integrity status of pipelines
Intelligent pigging of pipelines is a Statutory Requirement in Nigeria
Corrosion Inhibitor availability in Bonga was interrupted for short periods due to umbilical blockage
Bonga Asset expects positive assurance with proof that Bonga flowlines have “Technical Integrity”
Shell Nigeria Exploration & Production Co. 5 Bonga Production Flowline Loops – Pigging Challenges
Bonga has three 10” and one 12” Production Loops; (with outer pipe diameters of 12” and 14” respectively)
For flow assurance purposes Bonga Production Loops are Pipe-In-Pipe design
Inner pipe has non-standard wall thicknesses up to 28mm
Bonga Production Loops are designed for pigging
MFL Intelligent Pigging tools are not suitable for Pipe-In-Pipe design
Ultrasonic (UT) and Eddy Current tools can be used, but because of extra wall thickness and high operating pressures they are on the edge of technical limits
Pigging uses cargo oil & wells in the loop must be shut-in; i.e. deferment
Pigging is not possible during tanker off takes
The longest loop (PM5) approx 20 KM, was selected for inspection
Shell Nigeria Exploration & Production Co. 6 Bonga PM5 Loop Intelligent Pigging – Preparation
Simple technical requirements for required technology and cleanliness in ITT; strict specs for defect detection (e.g. pits 15% of thickness)
Contract awarded to a Nigerian service provider – Aug 2012
Tool engineering – Nov/Dec 2012
Tool modifications, Pull and Pump tests completed – Dec 2012 / Jan 2013
Tool and Personnel mobilisation – Jan 2013
Site survey, Pigging Procedures, HAZID/HAZOP/JHA, tool tests – Jan/Feb 2013
Pigging Procedures signed and approved – Feb 2013
Shell Nigeria Exploration & Production Co. 7 Intelligent Pigging – Execution
09/02/13, Low Density Foam Pig launched; received shattered
10/02/13, Medeium Density Foam Pig launched; received no damage
11/02/13, one Cup Pig followed by two Bi-Di Pig launched, all received without damage
12 and 13 Feb Tanker off take (no pigging activity)
14/02/13, 1st Gauge Pig launched; received dented
15/02/13, 2nd Gauge Pig launched; received slight damage, PM5 confirmed clean and ovality acceptable for Intelligent tools
15/02/13, Eddy Current tool launched; received undamaged and data quality confirmed
16/02/13, UT tool launched; received undamaged and data quality confirmed – End of PM5 pigging campaign
Shell Nigeria Exploration & Production Co. 8 Bonga Intelligent Pigging - Findings
Selected loop has the highest water cut and was suspected to have internal corrosion defects
Tools were selected for detection of metal loss including shallow internal corrosion
Detailed analysis of data confirmed that PM5 did not have internal corrosion defects
Only 9 incidents of minor milling defects and 6 minor external corrosion defect were detected
Data was verified by using two tools with different technologies
Intelligent pigging enabled the Pipeline Team to provide Bonga Asset with the assurance that PM5 has Technical Integrity
W-PIMS estimated remaining life of PM5 over 40 years
Shell Nigeria Exploration & Production Co. 9 Bonga Intelligent Pigging of PM5 Loop - Summary
Approx 1000 man-hours worked without Lost Time Incident
Campaign completed in 10 days, (originally planned for 21 days)
Total of 7 pig runs using foam, cup, scraper pigs completed to clean the loop and confirm safe passage
Two IP runs successfully completed using the latest available technology
The FIRST deepwater pipe-in-pipe inspection, in Shell, in Nigeria and possibly in the world
Pigging successfully completed by SNEPCO staff and Nigerian Contractor
Shell Nigeria Exploration & Production Co. 10
Bonga Intelligent Pigging – Foam Pigs to confirm passage
1- Low Density Foam arrives shattered, this 2- Medium Density Foam arrives intact; safe is not unexpected to launch cup pig
Shell Nigeria Exploration & Production Co. 11 Bonga Intelligent Pigging – Cup & Bi Di Scraper Pigs used for cleaning
3- Cup Pig received slight damage to sizing 4- Two Bi Di pigs with brush received in good plate. condition. Total debris only 4.5 kg, line is very clean !
Shell Nigeria Exploration & Production Co. 12 Bonga Intelligent Pigging – Gauge Pigs confirm ovality and “no obstructions”
5- The first gauge pig with noticeable dent to 6- The second gauge pig received with minimal plates, pipeline data logger attached to the back damage, line ovality and safe passage for intelligent of the pig (not seen in photo). For reassurance tools confirmed a second gauge pig is launched.
Shell Nigeria Exploration & Production Co. 13 Bonga Intelligent Pigging – XGP/SIC and UT Intelligent Pigs
8- At 23.30 Sat 16th Feb, the UT tool arrives back. 7- Intelligent tool ready for launch Job completed LTI free
Shell Nigeria Exploration & Production Co. 14 Bonga Intelligent Pigging – The Team
Bonga pigging Crew – Feb 2013
Shell Nigeria Exploration & Production Co. 15 List of Abbreviations
FPSO Floating Production Storage and Offloading
kbopd 1000 Barrels of Oil Per Day
kpwbd 1000 Barrels of Water Per Day
mmscf/d Million Standard Cubic Feet Per Day
JHA Job Hazard Analysis
HAZID Hazard Identification
HAZOP Hazards in Operation
MFL Magnetic Flux Leakage
Bi-Di Bi Directional
W-PIMS Web Pipeline Integrity Management System
Shell Nigeria Exploration & Production Co. 16 Disclaimer
The companies in which Royal Dutch Shell plc directly and indirectly owns investments are separate entities. In this presentation, “Shell”, “Shell group” and “Royal Dutch Shell” are sometimes used for convenience where references are made to Royal Dutch Shell plc and its subsidiaries in general. Likewise, the words “we”, “us” and “our” are also used to refer to subsidiaries in general or to those who work for them. These expressions are also used where no useful purpose is served by identifying the particular company or companies.
Shell Companies in Nigeria have their own separate identities but on this presentation we may sometimes use "Shell", "we" or "us" when we refer to Shell Companies in Nigeria in general or where no useful purpose is served by identifying any particular Shell Nigeria Company.
All information or advice provided as part of this presentation is intended to be general in nature and you should not rely on it in connection with the making of any decision. SNEPCo tries to ensure that all information provided as part of this presentation is correct at the time of inclusion on the presentation but does not guarantee the accuracy of such information.
SNEPCo is not liable for any action you may take as a result of relying on such information or advice or for any loss or damage suffered by you as a result of you taking this action.
Information is provided with the consent of NNPC, the Licence Holder
Shell Nigeria Exploration & Production Co. 17 Shell Projects and Technology Confidential 18