Gathering reliable metocean data for the Abadi LNG project

Client: Inpex

Purpose: To provide engineering design criteria for the proposed Abadi gas export pipeline and onshore LNG plant in Indonesia.

Project details: Two-year metocean survey, combined with 42 years of hindcast modelling. Survey began February 2020, with final study reports to be delivered in June 2022.

Data to support a Mega Gas development

Inpex tasked the partnership of PT Mahakarya Geo Survey and RPS with providing data to gain a full understanding of the metocean conditions affecting the engineering of the project, quantifying the physical environment with statistics relevant to engineering design. This information will support Inpex in building the proposed infrastructure of Floating Production Storage and Offload, Gas Export Pipeline, LNG jetty and LNG processing plant, safely and economically.

Greg Bush, General Manager, RPS Energy, explains, “We're providing the engineers with the prevailing environmental conditions they need to complete and build the project. With the 175 km long offshore pipeline (traversing a 1.5 km deep trench), the onshore plant and the offloading jetty, this kind of project is like three big engineering jobs in one.”

The client needs to know the metocean (meteorology and oceanography) information for the area including the pipeline, its route, and the shoreline. It can then be used to develop design parameters for engineering, to understand possible installation challenges and to guide operational planning. It supports our client in achieving their overall project goals: namely, to develop the field and get the gas produced to the market.

With very large developments such as these, clients need to be sure of metocean data accuracy. Greg says, “Our data is very important because it underpins all the engineering. Everything that will have an impact needs to be measured, and then the modelling and long-term statistics also need to be right.”

To be selected for this project, the consortium of MGS and RPS won a competitive tender based on our experience, capability, value and local partnerships. RPS’ solid track record in metocean design criteria, measurements and survey includes a previous oil pipeline design criteria project in Indonesia for Eni. We are well-known globally for supporting design criteria for LNG plants and pipelines. We have also provided these services for many oil and gas projects in the region, including Inpex’s Ichthys project in nearby Australia.

The PT. Mahakarya Geo Survey / RPS consortium has an established track record working in Indonesia, with MGS providing the local project management and RPS taking the technical lead. Both partners place great emphasis on safety and quality.

Running the project

To gather data for the Abadi project, MGS/RPS installed and maintained 17 oceanographic moorings along the pipeline route and at the jetty location. In addition, two onshore meteorological masts gathered data at the future location of the plant. The survey measured various onshore and offshore factors that might impact design, such as currents, winds, waves, water levels and water temperature. Concurrent with, and calibrated by the survey, we carried out atmospheric and oceanographic modelling to establish long-term statistics. Data on extreme conditions are used by engineers to design the reliability and survivability of structures, and information on ambient conditions is required for long-term considerations like fatigue.

Having finished the modelling, we are moving into the data analysis stage, to generate design criteria reports for use by the engineers building the infrastructure.

Project outcomes

• High data return on the completed Metocean survey
• Hindcast modelling complete
• Project completed successfully despite challenges caused by Covid-19
• Project won a Shell and INPEX safety award

For this type of project, the most commonly tracked quality parameter is data return, meaning the amount of data returned during the survey. The percentage data return for MGS/RPS’ work at Abadi was 94%,  achieved with 6-month service interval – higher than the industry average.

The project was also completed on schedule for our client, despite its complexity. RPS is known for the high quality and accuracy of our modelling – essential for this location, which is challenging to model due to the deep Timor Trough, the Indonesian Throughflow current feature (which drives influences from the Pacific into the Indian Ocean) and a general lack of measurements in the region to inform model forcing.

In addition, all site visits after the initial mobilisation were conducted in a Covid 19-affected world. We successfully managed Covid isolation measures during operations, including getting expatriate experts into Indonesia for the work and back home again, with required isolation quarantine periods. We also successfully kept our vessels in a Covid-free bubble, despite high rates of infection in Indonesia at the time. The project team won several INPEX awards for outstanding safety in relation to managing and executing the service during Covid-19.