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