Task Team Members: Ali Abdulkarim Finance Adviser KPC

1. K-Lead ProjectPipeline Leak Detection System (PLDS) Projects Implemented in KOC Gas PipelinesDecember, 2015 Task Team Members: Ali Abdulkarim Finance Adviser KPC Mohammad Al-Zoubi Manager Gas Operations KOC Falah Al-Enezi Manager Legal Affairs KGOC Meshal Al-Tanaib Manager Operations & Maintenance KAFCO

2. Table of Contents • Objectives of K-Lead Project • Importance of Sharing the PLDS Project Experience • Abstract: • PLDS Introduction • KOC Gas System Block Diagram • PLDS under KOC Gas & Condensate Network Telemetry • Methodology used in KOC-GO PLDS • Conclusion • More Information • Typical PLDS Implementation detail for NK 12” Condensate line

3. Objectives of K-Lead Project • The Objective of the K-Lead project is to share KOC Gas Operations’ experience, with other peers, on implementation of Pipeline Leak Detection System (PLDS) on its critical Gas & Condensate pipelines and the benefits of enhanced safety, environmental protection and availability of the facilities.

4. Importance of Sharing the PLDS Project Experience PLDS implementation in critical hydrocarbon lines leads to • Enhanced safety to people & property • Prevention of hazard exposure to the nearby population • Minimized environmental damage • Better pipeline management • Enhanced process facility availability

5. Abstract: PLDS Introduction • KOC Gas Operations (KOC-GO) operates various critical Rich and Lean Gas & Condensate Pipelines, of varying sizes, transporting hydrocarbons across Kuwait supplying major customers such as KNPC, MEW, Equate, etc. In the past, KOC-GO experienced considerable pipeline failures and hence implemented PLDS in the existing lines and future projects • There are four main categories of pipeline failures. • Pipeline corrosion & wear • Operations outside design limits (eg. Pressure, Temperature, etc.) • Unintentional third party damage • Intentional damage • PLDS methodologies are based on leak detection located externally or internally. • In KOC-GO, Internally based continuous On-Line Leak Detection on the principles based on Model Compensated Mass Balance, Pressure Surge and Dynamic Models have been implemented.

6. KOC Gas System Block Diagram Transmission Gathering HP Rich Gas Gathering Center Separation Scrubbing Measurement Flare Booster Station Compression Gas Dehydration Measurement Flare LPG & AGRP Plants in KNPC HP Rich Gas & Cond. LP Rich Gas MEW Power Stations & Other Users • KOC Gas & Condensate pipeline networks comprises of about 1400 km of pipelines ranging from 3” to 52” in size, connecting Gathering Centers (GCs), Booster Stations (BSs) and outside entities such as KNPC, MEW, Equate, etc. LP Lean Gas HP Lean Gas Liquid Fuel Distribution PLDS Gas Operations’ Facilities

7. PLDS under KOC Gas & Condensate Network Telemetry KOC Gas Production Metering of Production - M Instrumentation - I Gathering Centre Booster Station M Metering of Supply M M Flaring M I I & M M M MAIN MANIFOLDS Pipeline Networks M M FCV FG M M M Operations Maintenance Accounts Planning HSE KNPC MEW Others Management Information Centre Consumers Metering Consumption PLDS

8. Methodology used in KOC-GO PLDS Step-1: Develop Hydraulic Simulation Model for the Pipeline of interest • Real-Time-Transient-Model(RTTM) that provides a hydraulic online simulation of the pipeline for all operational conditions (steady-state and transient). • Results of the simulation Profiles of Flow, Pressure Gradient, Temperature, Density. • The RTTM is using equations of state (EOS) to mathematically emulate the fluid flow within the pipeline and this usually solves three partial differential equations online: for the conservation of mass, momentum and energy. • Line packing (Inventory) calculation is also performed in the RTTM to cater transient conditions. • Perform Tuning of Hydraulic Model (i.e. to adapt the model parameters to the reality).

9. Methodology used in KOC-GO PLDS Step-2: Model Compensated Mass Balance (MCMB) calculations is performed • The MCMB calculates mass balance from pressure, temperature and flow measurements. • The results of the RTTM simulated data is compared with the MCMB’s real-time data and accordingly leak is detected in case of any deviation. • In steady-state operation, differences between flow (In and Out) measurements indicate a leak situation. • In transient conditions, flow measurements alone are not reliable for the indication of a leak situation, but compensation via the pipeline contents is done. • MCMB is a reliable and high sensitive leak detection under transient conditions.

10. Methodology used in KOC-GO PLDS • Discrepancies or divergences between values calculated by the model and real time data shall be compared with dynamic and adjustable value and time dependent thresholds to provide warnings and alarms of the probability of a pipeline leak to the Gas Management Information System operators. • LDS Alarm threshold values are set in such a way that there will be no spurious alarms.

11. PLDS Architecture

12. Methodology used in KOC-GO PLDS Step-3: Identification of Leak Location using Pressure Surge Method • Pressure wave events are used to decide whether a leak must be suspected • An alarm is generated whenever several events have been detected • Whenever there is a negative pressure surge (pressure drop) the leak is located by evaluating pressure drop time stamps. • Pre-requisites: • Detection of pressure waves > 0.2 bar • Pressure drop event must be transmitted to LDS • Time stamping or high sampling frequency required • Risk of false alarms caused by normal operations (e.g. Pump switching) is avoided by confirming with MCMB alarms.

13. Methodology used in KOC-GO PLDS From Model Compensated Mass Balance: Step-4: Shut-in Balance to detect leak during stand-still: mBAL = mOUT - mIN - mINV During standstill only pipeline inventory calculation is required! Inventory variation depends on Pressure and Temperature variations Sections with different sizes are related to their respective inventory volume

14. Conclusion Having experienced that KOC-GO got benefitted in respect to Health, Safety, Environment, Productivity and Availability out of PLDS implementation in their critical lines, the same practice continues in KOC’s ongoing gas pipeline projects and will continue in the future projects. In the similar line of thought, we suggest our peer groups/companies to enjoy the benefits of PLDS by implementing such system in their facility pipeline projects.

15. Additional InformationTypical PLDS Implementation in 12-inch Condensate Line from KOC-NK to KNPC-MAA

16. Basics of Hydraulic Simulation Pressure (constant within node) Temperature (constant within node) node 2 node 1 pipe 12 p1 . . . p2 v1,ρ1 m23 m12 m12 v2, ρ2 T1 T2 v0 Δx pipe 01 mass flow (constant within pipe) velocity, density Basic equations are Basics of Hydraulic Simulation Conservation of mass Conservation of momentum ... applied to a „Finite Element Model“ of the pipeline grid State equation

17. Hydraulic Simulation for 12” Condensate Line from NK to KNPC-MAA Step 1: Calculate changes in flow profile from a given pressure profile Step 2: Calculate changes in pressure profile from a given flow profile Results of Simulation Profiles of density, Temperature, pressure gradient, flow

18. Hydraulic Simulation for 12” Condensate Line from NK to KNPC-MAA Difference between measured value & simulated value Simulated values of flow, Pressure & Density • Where available, additional pressure measurements are used for an additional model

19. 40,180 Bbl/d Model calculated flow (according to pressure drop 1,100 psi – 697 psi): > Pipeline efficiency of 92.08 % Tuning the Model for 12” Condensate Line from NK to KNPC-MAA Measured flow between Pt.“A“ and C/O: 43,307 Bbl/d That means, flow is 8% below optimal flow. Pipe friction factor will be adapted accordingly.

20. Model Compensated Mass Balance (MCMB) p T Q Model Compensated Mass Balance Calculate mass balance from pressure, temperature and flow measurements Use a hydraulic model to compensate for transient conditions

21. Model Compensated Mass Balance (MCMB) Accuracy of Hydraulic Model Accuracy of Instrumentation Accuracy depends on: Basic equation: mBAL = mOUT - mIN - mINV mBAL : Mass balance for a given time window mIN : Inlet mass (flow) mOUT : Outlet mass (flow) mINV : Change of mass inventory due to pressure and temperature mBAL = mOUT - mIN - mINV

22. Model Compensated Mass Balance (MCMB)

23. Model Compensated Mass Balance (MCMB) Model Compensated Mass Balance Remember: mBAL = - mIN + mOUT - mINV

24. Model Compensated Mass Balance (MCMB) Leak Case A: Suddenly appearing leak at Pt.“A“(mainly detected by pressure drop)

25. MCMB Trend Curves with 3 different time windows

26. Status indication PS not available

27. At the moment, thresholds are set to –0.04 and –0.05. Will be adapted during operation. Shut-in Balance

28. To be able to estimate real leak flow, section volume is indicated as well. -0.016 %/h leak flow means –0.016 · 693 / 100 = 0.11 bbl/h or 2.66 bpd Shut-in Balance

29. Averaging time for shut-in balance is 1 hour Shut-in Balance