Fast-Track Innovation Enables Life Extension of Ormen Lange Gas Field

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 35773, “Ormen Lange Gas Field: Fast-Track Innovation Enables Life Extension,” by Joakim Almqvist, SPE, Petter Solberg, and Svein-Arnes Marthinussen, SLB, et al. The paper has not been peer reviewed. Copyright 2025 Offshore Technology Conference. _ Ormen Lange is a mature asset in the Norwegian Sea in a water depth of 1000 m. Ormen Lange Phase 3 is a project aimed at increasing the total recovery from the field by using a new solution for seabed compression. The selected compression concept relies on the use of a suite of technologies to be cost-effective. However, this has required a qualification program to mature these technologies. The complete paper addresses how close collaboration between the operator, system contractor, and subsuppliers has enabled the development of a robust and cost-efficient solution for the project. Ormen Lange Compression The subsea wet gas compression (WGC) system will boost production from four templates connected to shore in a dual-flowline configuration (Fig. 1). A new compression manifold will be used to commingle the production streams from the four subsea template manifolds, distributing flow further to two subsea compression stations and returning boosted production through the compression manifold to the dual flowlines toward shore. Each compression station consists of two compressor modules, a cooler module, and a flow-control module. These modules are retrievable. When configured with the stations in parallel, the system achieves the highest volumetric flow-rate capacity. As production declines, however, system flexibility allows the compression stations to be configured in series to achieve a higher compression ratio. Each compressor has a capacity of 12 000 actual m3/h, a 10 000-m polytropic head, and 8 MW of combined shaft power. The station operates with a single variable speed drive (VSD) for both compressors, resulting in a total shaft power rating of 16 MW per compression train, or 32 MW for the entire system. The foundations and umbilicals for the compression system were installed in 2023, with main subsea structures installed in 2024. Modules will be installed in 2025, and system startup also is planned for later this year. The compression system will enable recovery of 30 billion–50 billion std m3 of additional gas. This brings the reservoir recovery factor up by 10 percentage points, from 75% to 85%. The subsea multiphase compression system will feature a best-in-class life-cycle carbon intensity because of its use of renewable electrical energy and the inherent energy efficiency of subsea compression. Technology Program The development strategy has, from the outset, included maximization of the field’s recovery through offshore compression, using either floating or subsea compression. To enable the selection of an optimal solution, the operator and its license partners invested heavily in various studies and technology programs ending with competitive pre-front-end engineering design (FEED) studies. The WGC system was ultimately selected, with the system contractor leading efforts to further derisk the technology.