Part 11 - Field Engineer vs Pipeline Engineer

Roles and Responsibilities Of Field Engineer

-Be conversant with the technical and commercial aspects of the projects and to have a full understanding of the scope of work, as provided be the Project Manager/Vessel Superintendent.

-To prepare offshore operations procedures at the requested by Project Manager.

-To prepare task plans during offshore operation based on the installation procedures.

-To become familiar with all the vessel operation/limitations, in order to improve design, operational schedule, procedures and safety.

-Participate in daily project meetings and toolbox talks.

-Liase with coordinate the activities of vendors and subcontractors as and when required as part of the Project, without commercial authority.

-Implement and organise any approved modifications to the Project, ensuring all changes are fully documentedand included in the appropriate documents.

Roles and Responsibilities Of Pipeline Engineer

-Review Client's technical documentation and requirements.

-Prepare the design and basis/CTRs for the pipeline design and interface with the relative process and structures and installation.

-Check  the result of surveys carried out by sub-contractors and optimise the laying route.

-Assist with the selection of spread/methods and perform/review installation design analysis for the pipeline system.

-Assist the pipeline lead or the project engineering manager for solving technical problems arising during project development and the interfacing/supporting the procurement department.

-Perform/verify all discipline analyses and calculation notes required to design the pipelines system, including the engineering activities of third parties/sub contractors.

-Define Standards and procedures for the relative engineering area and contribute to software evaluations.

-Solve all the engineering problems arisen from day to day installation works.

-To ensure safe and efficient offshore installation operations.

-To find the optimum and the best rectification design of any repair.

-Engineering analysis scope of work details :

1. 
   
   Pipelay analyses using pipelay barge.
   
   
   
2. 
   
   Riser installation & davit lifts analyses.
   
   
   
3. 
   
   Pipeline Spanning calculations
   
   
   
4. 
   
   Stinger ballast calculations check.
   
   
   
5. 
   
   Pipeline sidewalking analyses.
   
   
   
6. 
   
   Abandonment & recovery analyses.
   
   
   
7. 
   
   Pipeline bowstring & anchor start-up
   
   
   
8. 
   
   Mid point tie-in analyses.
   
   
   

Continue of Part 9 - On Bottom Stability Analysis

On Bottom Stability Using AGA

Level 1

-Its calculate the static stability

-Airy waves theory and Morison force apply

- A cohesive soil retains its restraining force

Level 2

-Calculates value of design wave height spectral density function

-The peak frequency of the bottom velocity spectrum is determined

-Maximum and minimum in-line hydrodynamic forces for the largest 200 waves contained in an assumed 4-hours long build-up sea state are calculated.

-Maximum and minimum in-line forces for the largest 50 waves during a subsequent 3hours long design sea stated are as in step above.

-Hydrodynamic forces for a complete cycle are calculated for four level of bottom velocity which are expected in a 3hours long design sea state.

-The four bottom velocities are :

• U1/3 = 1.0Us
• U1/10 = 1.27Us
• U1/100 = 1.66Us
• U1/1000 = 1.86Us

Output example from my project before :

Part 10 - Offshore Trip For 28in KUMANG Pipeline

I've been given a task by Enterprise 3 OCS for going to offshore KUMANG monitorized 28in KAKG-A to MLNG-2 pipeline lay & recovery @50m WD. It's a good experience step where I've been exposed for laying a bigger and heavier pipeline.


At the first day on board, I am setup the stinger rollers and collected some information about the rollers condition for reporting purposes to office. The next day, Enterprise 3 is towing from kp 186 nearshore to KP104 at offshore for recovery the 28in pipeline and the journey takes 10hours. Once the barge ready at the location, anchors have been deploy with respect to the pattern done by field engineer.

For this job, pipeline analysis is done by me, and as per OFFPIPE shows the marginal stresses which is almost to allowable stresses, where further details are monitorized to aviod from pipeline buckle. But, everything just follow the plan and 28in pipeline is recovered during day shift.

HOT NEWS - MALAYSIA OIL & GAS

Seven in running for Petronas tender

By Tan Hwee Hwee

Seven contractors are said to be running for the five transportation and installation packages offered under the Petronas’ umbrella tender issued on behalf of 11 PSC operators in Malaysia. The contenders include the five mentioned in an earlier report : SapuraCrest’s affiliate, TL Offshore, Bumi Armada-J Ray McDermott, Saipem, Sigurros and PBJV, as well as Global Industries and private Malaysian outfit, Master Offshore.

TL Offshore and the partnership between Bumi Armada and J Ray McDermott, are likely to go for all five packages. Saipem, Global Industries and the three other Malaysian contractors are said to be eyeing at most three of the offered packages, according to industry sources. Of the three smaller Malaysian contractors, PBJV is expected to go on a lone bid for the pipelay packages. Sigurros is said to be seeking a partnership with Sime Darby, while Master Offshore may be looking at recruiting more third party vessels for the bid round.

The final contract or contracts to be awarded will run for a minimum of three years from the second quarter of next year and includes two options each for one year extension. The work scope for 2010 and 2011 has been released and will be executed over a minimum of 84 days and up to 229 days each year. The remaining work for the next three years from 2011 through 2013 will be firmed up during or after the third quarter of 2011.

Work will be carried out using a full marine spread including derrick and/or pipelayers, diving support vessels and anchor handling tug supply vessels. Bids are due for submission in July and the contract could be awarded as early as this November. Industry observers said the firm three-year contract could be worth 3 billion ringgit ($850 million).

Friday, 10 July, 2009, 08:18 GMT last updated: Friday, 10 July, 2009, 08:45 GMT

Part 9 - Pipeline On Bottom Stability Analysis

Pipeline on bottom stability is an interaction of pipe, water and soil. The important factor that taken into account is the water flow whereby determining the magnitude and time variation of hydrodynamic drag and lift forces.

The second factor is soil. There have 3 friction will happened which are static, sliding and cohesive friction. So, it’s very important to understand the soil condition at the pipeline route area so that accuracy of analysis achieved.

These are some input provided for on bottom stability analysis :
1. Pipeline Data

Outside diameter
Wall thickness
Density of Pipe
Corrosion Coating Thickness
Corrosion Coating Density
Concrete Coating Thickness
Concrete Coating Density
Field Joint Material Density
Concrete Coating Cutback
Corrosion Coating Cutback
Pipe Joint Length

2. Wave and Current Data

Significant Wave Height (Hs)
Spectral Peak Period (Tp)
Wave Angle
Wave Spectrum Type
Water Depth
Current Velocity
Current References Height from Bottom
Peakedness Parameter

3. Physical Parameter

Density of Content
Density of Seawater
Marine Growth Thickness
Soil Type
Mean Grain Size – DNV RP E305
Roughness – DNV RP E305
Undrained Shear Strength (Su) – DNV RP E305
Lift Coefficient – –DNV RP E305
Drag Coefficient – DNV RP E305
Inertial Coefficient – DNV RP E305

Follow Part 9 for continuing of On Bottom Stability using AGA method

Part 8 - Wall Thickness Design

Wall Thickness Analysis

The selected wall thickness shall be satisfying each of the following requirements:
· Internal Pressure Containment;
· Hydrostatic Collapse;
· Local Buckling
· Buckle Initiation
· Propagation Buckling.

a) Internal Pressure Containment
For pipelines and risers the tensile hoop stress due to the difference between internal and external pressures.

b) Hydrostatic Collapse

During pipeline installation, the pipe is required to sustain the net external pressure without yielding or collapse. This is of particularly of significance in deep water where the external hydrostatic pressure alone may cause the pipe to collapse in plastic mode. Collapse pressure is usually defined as the pressure required causing a local collapse due to external water pressure, pipe imperfections, bending and tension.

c) Local Buckling

The local buckling calculation method is outlined in DnV 1981. Conservatively, the minimum pipeline radius of curvature used in the local buckling analysis is calculated.

d) Buckle Initiation

For a pipe in water depth where the net external pressure is less than that of propagation, any damage to the pipe will remain local. Even if the external pressure is higher than the propagation pressure, damage to the pipe still requires a pressure high enough to trigger unstable collapse for subsequent propagation of the damaged section. Evidently, such a dynamic collapse will stop once the propagation front encounters a physical obstruction, such as an adequate increase in wall thickness (buckle arrestor), or lowering of pressure to below the characteristics propagation value (shallow water).

Unlike buckle propagation which is, in essence, a unique property of a particular pipe section, buckle initiation is not only a function of pipe geometry and material properties but is also dependent upon initial imperfection levels and impact or deformation energy. Initial imperfections may be in the form of geometrical distortions, material defects and/or load induced deformation.

For this reason, prediction of buckle initiation relies heavily upon information on the level and form of any initial imperfection. Impact or deformation energy can result in buckles during installation or significant dropped object.

e) Propagation Buckling

Buckle propagation is related to a situation where a transverse dent, caused by excessive bending, or any other causes, changes its configuration into a longitudinal buckle and propagates along the pipe, causing collapse of the pipe along its traveling length. The driving energy, which causes a buckle to propagate, is the external hydrostatic pressure.

The nature of a propagation buckle is that a greater pressure level is required to initiate a propagation buckle, called buckle initiation pressure, than the pressure required to maintain propagation of the buckle. As a consequence of this, a buckle initiated in an offshore pipeline propagates and collapses the line until the external pressure becomes equal to or less than the propagation pressure.

Many theoretical and experimental investigations had been made by various organisations to study buckle propagation and to determine the propagation pressure for offshore pipelines. These studies have resulted in similar but rather simple expressions for calculating the propagation pressure, Ppr.

Part 7 - Offshore Trip to Dulang Replacement Pipeline

This is the 3rd trip I'm going to Enterprise 3 barge, and 2nd time to offshore. Actually this is considered the best project for me because all installation analysis done by me, and also a lot of activities happened during the construction.I had given a task from OCS to become a field engineer and at the same time need to achieve some calculation on board in case any other installation problem happen.

For this job, I've taken a chance to see all the installation method that I analyze in the office like bowstring start-up, pipelay, abandonment, sidewalk, pipeline lifting analysis and pre-commisioning works. In addition, acting as a field engineer bring me to the new journey of offshore construction environment, start from scratch until the pipeline ready for production.

The best thing is, knowlegde in pipeline installation analysis give me fastest way to understand and realize what we are doing and at the same time self defence from all question about pipeline design and installation. About the barge, previous trip plus mobilization work that I involved for Enterprise 3 shows me the equipment and consideration that taken into account to produce the pipelay barge.