Projects concerning older "brownfield" installations, as opposed to "greenfield" new build projects, will become increasingly frequent given the quality of the installations built and the desire to spread their costs over as long a life cycle as possible. Eventually installations have to be decommissioned in order to leave the sites clean. Even more so in the nuclear sector, where decommissioning installations is accompanied by decontamination, which is an essential part of protecting the environment.
Modification projects (i.e. revamping projects) on old brownfield installations are chosen in order to maintain operating performance (for example to drive performance in a mature field by connecting new wells or injecting high pressure gas), comply with changes to regulatory requirements (reduction in flare gas), and improve process control systems or operating safety by introducing the latest instrumentation or data exchange and processing technology.
These projects involve process installations, which fall within the remit of chemistry, and in particular oil and gas installations both upstream with the production of oil and gas, and downstream in relation to transport, storage, distribution, refining, and petrochemicals.
As production shutdown costs are much higher than the cost of work, shutdowns must be minimized by completing as much of the work as possible either prior to or after the shutdown phase. However, work on units that are in operation simultaneously mobilize people working in different disciplines in addition to operating staff. As these side by side working conditions may be difficult and potentially dangerous, they should if possible be avoided.
With this in mind, brownfield engineering includes a detailed study of the possibilities of prefabrication, modularization, early delivery of equipment, with the aim of ensuring the work to be undertaken during shutdown only consists of disassembling, installing, and connecting – and avoiding the unexpected which can be very expensive, especially offshore.
The keys to success are communication with the operator to take into account feedback (safety reviews, constructability, operability, and maintainability), and the reliability of the data on the existing installation: 3D laser scans, up to date plans and data sheets on the equipment in place, etc.
Sofren consultants assigned to brownfield projects have great technical expertise, in particular in organizing and planning work, processes and integrated packages, 3D studies of fluid networks, control / command systems, and also a proven ability to work as part of a project team.
Process installations are designed to ensure technical and economic profitability over a set period of time (life cycle), which is usually in the region of 20 to 50 years. When it is decided not to revamp an installation because it is dilapidated and dangerous, operations have to be shut down and the installation decommissioned. Sofren is involved in decommissioning these installations – onshore or offshore and in oil, gas, nuclear and other industries.
The chemistry-related aspects of decontaminating structures and the soil are delicate and closely supervised by the authorities because these installations may expose urban populations to some highly toxic chemicals. Installations present fire, explosion, air, and soil pollution risks (for example radioactive emissions).
Operators are responsible for compliance with the regulations and any damage that may be caused. Profitability studies now include the cost of decommissioning.
There are three phases in decommissioning: the first is shutting down the process and disposing of products, this operation is conducted by fluid circuits or "systems". Products are removed to appropriate locations for reuse or incineration, the installations are then powered down by decompressing the networks, and then the power supply is cut off. The second phase is deconstruction based on a sequence of work for each discipline (the dismantling blueprint). The last phase consists of restoring the site in accordance with the applicable regulatory requirements, the duration and cost of which are related to the difficulty of rehabilitating the soil and the requirements for returning it to a natural state.
Decommissioning projects are the projects of the future, budgeted in the long-term; they are technically complex and require skills in all disciplines, including processes and commissioning. As it is not an investment for the operator but an obligation, studies and works are designed to minimize costs while still complying with the regulations. SOFREN combines its technical expertise with its project management expertise to provide achievable decommissioning solutions, including recycling all the materials and waste that are still recoverable.