Previous FYPs

Optimum Growth and Thickness of Wax Around Deepwater Pipeline's Circumference

Student: Victor Tang Quoc Thai (15771)(First Class Honors. Petrovietnam. Now in Robert Bosch Vietnam, AI Lab)

Supervisor: Dr. William Pao

Terms: Semester 3, 2014 and Semester 1, 2015

Synopsis: With the ongoing trend in deep water developments, flow assurance has become a major technical and economic issue. The avoidance or remediation of wax deposition is one key aspect of flow assurance. The ability to predict wax precipitation depends on a number of factors, one of which is examined in this paper: the thermodynamic equilibrium between oil and wax. A numerical model is developed based on the solid-solution theory with the assumption that the precipitated wax forms a homogeneous phase. The objectives of this work are to develop a prediction model to estimate the wax appearance temperature and the amount of wax will be precipitated. In addition, the optimization process is conducted to match the developed model with field data from Malaysia region in order to make the result of this current research become realistic and useful for the local applications. These objectives are obtained by implementation of the numerical model in MATLAB environment to proceed a large amount of calculations accurately. The methodology consists of several stages i.e. wax prediction model development, preliminary result to determine suitable range of carbon number for sensitivity analysis, and tuning process. The present study shows that the fusion temperature mainly influences the thermodynamic model of wax precipitation; while the effect of enthalpy of fusion and solubility parameter is insignificant. Tuning process based on the sensitivity analysis identifies that the regular solution theory is the only suitable model to represent solid phase, and the UNIFAC model is incapable of modelling liquid phase. The developed model in this work is optimized using Malaysia crude oils data, the outcomes are acceptable while approaching experimental data of wax appearance temperature and wax percentage at different temperatures.

Paper submitted: Fluid Phase Equilibria. Impact factor: 2.2

Operations Reporting Enhancement (ORE) for Petroleum Management Unit, PETRONAS

Student: Mohd. Amirul Zoklefle (CIS. First Class Honors.)

Supervisors: Dr. Yong, Dr. William Pao

Terms: Semester 1 & 2 2014

Collaborator: PETRONAS/PMU

Synopsis: Confidential.

CFD Improvement of the Torpedo Anchor's Aerodynamics for Deeper Penetration

Student: Soh Boon Ping (First Class Honors. currently with wells/PCSB)

Terms: Semester 1 & 2 2014

Award: 33rd SEDEX Bronze Medal

Synopsis: Torpedo shaped anchor is a innovative and robust anchor solution for deep water floating structures. It is designed in such a way that after being released from a certain height above the seabed, it is then installed well into the seabed by penetration. The velocities after the drop can be very high through the water, and the anchor itself may have dry weight of 50-100 tonnes, and height of 10 -15 m. Due to increasing number of exploration activities being carried out in deeper offshore regions, there is a need for torpedo anchor to achieve higher terminal velocity before its penetration. This will subsequently allow deeper penetration of the anchor, and develop greater holding capacity for the offshore structures. Therefore, this project aims to define ways of improvements for attaining higher terminal velocity. At the same time, relationships between various affecting parameters with their resulted drag coefficient will be developed.

Publication:

Soh BP, Pao W, Al-Kayiem HH (2015) Numerical analyses for improved hydrodynamics of deep water torpedo anchor. IOP Conference Series: Materials Science and Engineering, Vol. 100, Issue 1, paper ID: 012059.

Gas Liquid Separation by Cylindrical Cyclone - GLCC 3D CFD ModelStudent: Jesse Chung (currently SKO/PCSB, Miri)Supervisors: Dr. Setyamartana Parman, Dr. William PaoTerms: Semester 1 & 2 2014Synopsis: Gas-liquid separation is one of the major processes on an oil and gas drilling platform. Conventionally, large separators are used to separate the product of drilling (gas and liquid) before other processes due to the capability of the equipment downstream of the separators. However, the nature of flow and the fluid behavior in the GLCC remain as the major challenges due to abundant of parameters affecting it. Therefore, this study aims to study the parameters such as mixture velocity, operational pressure, and geometry effects on the separation efficiency of the GLCC. The main objective of this study is to develop a correlation between the geometric effect of the GLCC, the operational envelope (velocity and pressure) to the separation efficiency of the GLCC. In order to understand the relation, ANSYS FLUENT is used to simulate the flow and the separation of the gas and liquid in the GLCC. To ensure the accuracy and correctness of the developed model, a validation is done by comparing the results from the simulation to available result of a prototype study. Mesh convergent check was performed to ensure the accuracy of results.

Passive and Partial Wet Gas Separation in Branched JunctionsStudent: Simon Kong (First Class Honors.)Terms: Semester 1 & 2 2014Synopsis: In the oil and gas industries, T-junctions are widely used in distributing gas-liquid flow through piping network. Due to the nature of splitting of gas-liquid flow in T-junction, this scenario rises a challenge in maintaining homogeneous splitting across T-junction. Besides, understanding the behavior of gas-liquid flow through T-junction is complicated as there are numerous variables that will influence on the splitting nature. Thus, the main objective of this project is to analyze the correlation of geometries and operating conditions onto the efficiency of phase separation in T-junction regarding to the fraction of gas taken off in side arm. The interested parameters under this study are the diameter of methane bubble, diameter of side arm, length of side arm, mass split ratio at side arm, rotation angle of side arm relative to the horizontal main arm axis, and superficial velocity of gas and liquid. Besides, the T-junction model is built in ANSYS Fluent for analyzing the efficiency of phase separation and also two validations are done in ensuring the applicability of the T-junction model in analyzing the phase separation. It is observed that the mass split ratio at side arm plays the most important role on phase separation, followed by inlet gas saturation and diameter of gas bubble. Conversely, rotational angle of side arm relative to horizontal main arm has least impact on phase separation efficiency. Gas velocity, length of side arm and diameter of side arm have comparable level of influential onto the efficiency of phase separation.

Software Application of Facilities Engineering & Reliability, SAFERStudent: Chiam Dar Siang (current SHELL Oil Company)Supervisors: Dr. Masdi Muhammad, Dr. William Pao

Terms: Semester 1 & 2 2014

Synopsis: Facilities engineer’s jobs can be very diversify in nature as they involve taking on many hats and roles such as plan and implements the design of plants, maximize the production efficiency and so on. One of the essential task is to perform a whole host of back-of-envelope compliance calculations. All of these regulatory are very useful as they could determine the mechanical integrity and the plant performance. However, it could become very tedious and horrendous when one try to assess all the scattering information or compliance at a time. Despite the fact that the difficulty of the calculation is relatively simple and straightforward but it would serves as a constant nightmare if those calculation are not organized accordingly. Hence, the purpose of this study is to design a universal platform that could systematically integrate and host a wide array of toolkits. These toolkits could cover all the available compliance regulatory such as ASME, API, EC and so on. The platform is developed and designed using Microsoft Visual Studio hence it could be easily installed on any version of Window operating system. Once the toolkits are developed, it could then be integrated into the platform thus providing a much organized family tree. From there, the engineer could access to any of the toolkits easily without breaking a sweat. The author successfully developed the platform and implemented with one of the toolkits developed by him. The toolkit developed is centrifugal compressor performance analyzer which is used to determine the polytrophic head and polytrophic efficiency of a centrifugal compressor. The application would provide the engineers information regarding the state of the compressor and allow the inspection and maintenance activity could be prioritized more effectively.

Tidal Wave Impact on Deepwater Offshore StructuresStudent: Alex Chai Kong Seng (currently Sapura-Kencana)Terms: Semester 1 & 2 2014Award: 33rd SEDEX Bronze Medal

Synopsis: Deepwater offshore structures are subjected to the risk of extreme wave loading that might destabilize the structures and eventually result in platform collapse, oil spill, or loss of life. Quasi-periodic wave like La Nina and El-Nino can generate tidal waves hundreds of meter height under favourable weather condition. This possesses a grave challenge to the floating structures operating in the South China Sea, Malaysia. Hence, the studies of wave-structure interaction when the wave impacts the structure are very important to offshore structure design and construction. This project focuses on the numerical simulation of extreme wave loading on the floating structures in deep water for determining the wave impact pressure and translational vibratory motion of the floating structure at different wave height and water depth by using proprietary code. A method validation is done by comparing the simulation and experimental result for the dam breaking problem.

Two Phase Oil Water Separation in Upstream Pipeline

Student: Kueh Shao Xiong (First Class Honors. currently SKO/PCSB, Miri)

Terms: Semester 1 & 2 2014

Synopsis: T-junctions are very common within pipe networks in a wide range of industrial applications in the chemical and petroleum industries. Understanding the behavior of liquid-liquid two-phase flow through a T-junction is very important as it has significant effect on the operation, maintenance and efficiency of the components downstream from the junction. Specifically this project objectives are i) to investigate the geometric effect on separation efficiency in T-junction, and ii) to analyze the fraction of oil taken off in a T-junction at different operating conditions and parameters. The phase distribution of the two-phase flow is simulated using FLUENT. The diameter ratio, length ratio, inlet oil fraction, density ratio and mixture velocity ratio are identified as the main factors affecting the fraction of oil taken off in T-junction. At the end of this project, it is observed that the density ratio plays the most important role on phase separation, followed by mixture velocity ratio and length ratio. Conversely, both diameter ratio and inlet oil fraction have least impact on phase separation efficiency. The efficiency of phase separation and the geometric effect of the T-junctions on the flow split are understood in order to achieve an optimum passive separation performance for optimal operation of downstream components from the junction.

Plastering Effects in Casing-while-DrillingStudent: Aidil Aizat b Mohamad Farid (ME13015, Schlumberger Malaysia)Synopsis: Casing while Drilling is simultaneous process of drilling and running casing. One of the benefits using Casing while Drilling technology is plastering effect. Plastering effect or smearing effect is a process where cuttings and drilling mud are plaster to the borehole by force of casing due to small clearance between the annulus. This creates a thin mud cake that is less porous and less permeable, that helping to increase wellbore strength and reduce lost circulation during drilling. However, due to inconsistency of plastering effect during Casing while Drilling operation, it is hard to determine the factors that enhance plastering effect. The objective for this project is to determine the plastering effect factors using parametric studies. This project will focusing on vertical well and five drilling parameters. The parameters are casing size to wellbore size ratio, casing eccentricity, casing rotational speed, annular velocity and cutting volume fraction. For methodology, base case model is selected, such as the wellbore size of 0.4m and length of 4.2m. The simulation will be using two type of drilling fluid which is Newtonian and non-Newtonian fluid. Conclusion from the parametric study, in non-Newtonian fluid, the most contributing factors are cutting volume fraction, casing size to wellbore size ratio and casing rotational speed. While annular velocity and casing eccentricity does not contribute much. For Newtonian fluid, the most contributing factors are cutting volume fraction and casing size to open hole size ratio. While annular velocity, casing rotational speed and casing eccentricity still give lesser contribution in plastering effect. Comparing non-Newtonian and Newtonian fluid based on mud cake thickness and length, plastering effect are easily to produce in Newtonian fluid.

Two-Phase Simulation of Well KillStudent: Moshey A. William (ME13174, now SBO/PCSB, Rotating Equipment)Terms: Semester 2 & 3 2013 (completed)Synopsis: The term “bullheading” refers to the pumping or squeezing of fluids into the well against pressure in order to force escaped gas into the formation. The purpose of initiating a bullheading procedure is to suppressthe formation fluid from goes into the surface that have the potential of causing blow-out during drilling operations and also to kill a well. Furthermore, drilling crews has no control over the fluid flow which usually enters the weakest formation. It is common in well killing method but little written information is available in this area. The aim of this research is to simulate a two phase bullheading operation in well killing using computer based simulation tool, ANSYS FLUENT. This study is conducted by using water as the killing fluid and gas as the escaped gas from the formation. Simulation is conducted by having two fluids in contact having different parameters. Based on the simulation, the volume fractionand the pressure drop between two different fluids in contact along tubing are determined and analyzed. The simulation is done based on the integration of two mathematical models. The first model is known as the “Non-Slip Theory” which assumes that there is no mixing of gas and kill fluid as a result only gas is leaked off. The second model is the “Slip Theory” which assuming a two-phase flow that takes into accounts the necessary well-face pressure to leak-off kill-fluid to the formation. The parameters used are complying with bullheading procedure and incorporated in the computer based simulation tool. At the end of the study,the overall simulation of the two phasebullheadingmay use to assist in predicting the killing parameters to ensure a successful bullheading operation in well killing.In addition, the killing factors are examined to identify which affecting the most based on the results obtained. It is hope that this research benefits engineers especially in well control in petroleum industry.

Numerical Simulation of Liquid-Liquid Flow Separation in T-JunctionStudent: Siti Hajar Aisyah bt Mat Soh (PE13379)Terms: Semester 2 & 3 2013 (completed)Synopsis: T-junctions are very common within pipe networks in a wide range of industrial applications in the chemical and petroleum industries. Understanding the behavior of liquid-liquid two-phase flow through a T-junction is very important as it has significant effect on the operation, maintenance and efficiency of the components downstream from the junction. Specifically this project objectives are i) to investigate the geometric effect on separation efficiency in T-junction, and ii) to analyze the fraction of oil taken off in a T-junction at different operating conditions and parameters. The phase distribution of the two-phase flow is simulated using FLUENT. The diameter ratio, length ratio, inlet oil fraction, density ratio and mixture velocity ratio are identified as the main factors affecting the fraction of oil taken off in T-junction. At the end of this project, it is observed that the density ratio plays the most important role on phase separation, followed by mixture velocity ratio and length ratio. Conversely, both diameter ratio and inlet oil fraction have least impact on phase separation efficiency. The efficiency of phase separation and the geometric effect of the T-junctions on the flow split are understood in order to achieve an optimum passive separation performance for optimal operation of downstream components from the junction.

PRIMA II - Pipe Risk Inspection and Maintenance AnalysisStudent: Melissa Bei Denis (PE13115, now with SKO/PCSB)Terms: Semester 2 & 3 2013 (completed)Synopsis: Pipeline inspection program is an approach to monitor the performance of the pipeline over time. The program required systematic detailed plan that can be executed and implemented in order to optimize the pipe operating life and minimize failure risk. In oil and gas industry, most of the piping systems are used to transmit high risk fluid containing hydrocarbon. Failure of the pipe such as leakage may cause hazard to human and environment. Periodic inspection and maintenance is crucial to continuously assess the piping system. Every piping system needs to be inspected at least once a year to ensure pipe integrity. Pipe Risk Inspection and Maintenance Analysis (PRIMA) is an integrated tool to improve pipe inspection routine where the monthly inspection plan, piping system assessment, predicted inspection interval and database management are automatically and bundled and integrated via graphical user interface. The objectives of this project aimed to enhance PRIMA’s capabilities in pipeline maintenance scheduling, communication management, inspection load prioritization, critical pipe life estimation and PRIMA Helpdesk. PRIMA will enable the user to preview the monthly inspection plan and alert the inspection team through automated email reminder. The user is able to monitor the piping performance, update and predicts the piping system to make important economic and safety decision. Further enhancement to PRIMA included an automatic alert in the PRIMA output report if it detects any critical pipeline thickness. This project will benefit engineers and plant inspector that is servicing piping inspection related to industrial process piping. PRIMA is developed in accordance and compliance with the pipe and piping standard and codes used in the industry, such as American Petroleum Institute (API) and American Society of Mechanical Engineer (ASME).

Numerical Simulation of Two-Phase Separation in T-junction

Students: Low Huei Ming, 12637 (Exxon Mobil Singapore)

Terms: Semester 1 & 2 2013 (completed)

Award: SEDEX 2013 Bronze Medal

Resource: Poster

Synopsis:T-junctions are commonly used in distributing two-phase flow by piping networks especially in oil and gas industries. However, the nature splitting of liquid-gas phases is a major challenge and is complicated due to the large number of variables that influence it. Understanding the behavior of two-phase flow through a T-junction is very essential as it has significant impact on oil and gas transportation pipeline networks, operation and control of process and power industries and lastly the maintenance efficiency of all the components downstream from the junction. This paper provides a detailed analysis on the effect of associated variables on phase separation efficiency in T-junction. Hence, the analysis uses and develops a numerical model for simulation of two-phase flow distribution in T-junction to elucidate an in depth understanding on two-phase separation at different operating conditions and parameters. In order to achieve the objective, the developed model consists of horizontal main arm and vertical side arm while CFD method is employed to simulate the fluid flow. The present study identifies that the overall mass split ratio, the initial gas saturation and gas density are the most influential factors on fraction of gas taken off in T-junction. Subsequently, the effect of inclination angle of gravity on flow split is investigated and it does not play a significant role on phase separation. At the end of this project, the phenomenon of phase maldistribution when a two-phase mixture passes through a T-junctions is well understood and hence the underlying potential as a simple, cost saving, passive partial separator is able to be included in the design of pipeline networks in the petroleum industry.

Publication

• 1. Pao W, Hashim FM, Low HM (2014) Numerical investigation of gas separation in T-junction. International Conference on Mathematics, Engineering and Industrial Applications, 28-30 May Penang. Proceeding of American Institute of Physics Conf. Proc., 1660, ID:070001.

1. Pao W, Hashim FM, Low HM (2014) Computational analyses of passive wet gas separation in branched piping. The 4th International Conference on Production, Energy and Reliability, 3-5 June KLCC. MATEC Proceeding.