Offshore focus: Single Point Moorings

A single point mooring (SPM) is a loading buoy anchored offshore that serves as a mooring point and interconnect for tankers loading or offloading gas or fluid products. SBMs are the link between the geostatic subsea manifold connections and the weathervaning tanker. They are capable of handling any size ship, even very large crude carriers (VLCC) where no alternative facility is available.

Oil & Gas Middle East met SOFEC’s manager of marine terminals, David Waronoff to discover what advances are being made in the offshore realm of the SPM.

What the types of SPMs are available to the oil and gas industry?

DW: Single Point Moorings are generally understood to be associated with vessels moored at a fixed location which weathervane around a single point. These SPMs are floating production, storage and offloading (FPSOs), FSOs, tower yokes, single anchor leg mooring systems (SALMs) and catenary anchor leg mooring systems (CALMs).

FPSOs and FSOs can incorporate either external or internal turrets and the internal turrets can be either permanent installations or disconnectable systems. SOFEC has provided all of these types of SPM systems to the worldwide offshore oil and gas industry.

SOFEC has installed systems offshore every continent except Antarctica. In 1974 the company delivered its first SALM to Malaysia, and made its Middle East debut for Saudi Aramco’s Ju’ Aymah SALM in 1976. SOFEC’s first CALM buoy was delivered to Malaysia in 1982. In 1987 the company was awarded its first project for an external turret moored SPM, which incidentally was a conversion of the worlds largest storage tanker, to Yemen Exploration and Production Company. This was installed in the Red Sea back in 1988.

What is SOFEC’s market share in the Middle East?

DW: We have a very strong presence in the region. Our installations span from Kuwait to Yemen. We have done work for, and supplied systems to, Kuwait Oil Company, ADCO, ADMA OPCO, Aramco and Hunt Yemen. The company is currently working with KOC to complete the commissioning of their CALM Buoy upgrade project. We also used local Kuwait fabrication of upgrade the CALMs we supplied in 1977.

What are the specific requirements of SPMs in the Middle East?

DW: The majority of the projects in the Middle East involve crude oil export operations which are normally handled via CALM buoy terminals. The oil tankers chartered throughout the region include the largest tankers ever built. Although the worldwide fleet has moved toward slightly smaller tonnage, there are still tankers in excess of 450 000 dead weight tonnes mooring to our CALM buoys and moving oil to worldwide markets.

How much would a typical SPM cost in the Middle East?

DW: There are many factors related to costs of systems. Environmental factors such as water depth, operating and survival environmental conditions including wave heights, wind and current forces, and tanker sizes all play a significant role. Also, the complexities associated with safety systems, telemetry and controls and power requirements have a large influence.

Additionally, the CALM Buoy System includes many ancillary items that also greatly contribute to the overall cost. These ancillaries include the pipeline end manifold, loading hoses (both subsea and floating), and mooring hawsers.

Typical CALM Buoy systems including all ancillary equipment, but not installation and pipelines, can range from US$12million to $20million.

What developments, in terms of new improvements, have been made by Sofec with regards to your SPMs?

DW: If you want to look globally, we are most proud of our disconnectable turret moorings. SOFEC installed the first system in the South China Sea in 1993. That system constituted a single riser system and a fairly small diameter turret. Since then, SOFEC has designed and installed systems with significantly more risers, larger diameters and with more complex safely and control systems in Canada and Australia. The systems are designed to disconnect to avoid massive ice bergs or sail away from severe typhoons.

These disconnectable systems are continuing to evolve and we are in the process of working on a FEED study looking at a disconnectable system due to arctic ice loading on the largest system in the world today.

Whenever an improvement is made to any one system, we try to apply a similar improvement to the other projects throughout the organization. This cross pollinating philosophy has yielded improvements in connection capability, mooring leg design, and structural design for all our product lines.

If you want to consider the CALM buoy systems we are working on in the Middle East, the major improvements over the years have been to the telemetry and controls systems. These are typically highly reliable safety oriented systems that can be fully integrated into local onshore distributed control systems. We can interface directly with the onshore pump controls to initiate emergency shut downs – on those rare occasions when they are required.

What is SOFEC’s strategy moving into 2010?

DW: We will continue to aggressively pursue the projects in this business sector. Due to the number of projects being delayed to late 2009 or pushed to 2010, we will be forced to compete in an even tighter market condition. However, because we are in position where the backlog from sales in 2008 is very strong, we have some flexibility in our choice of projects to target.

This will allow us to keep focus on the projects that fit our business model and not force us to settle for projects that do not fit our company.