Product systems

Floating production systems offer production facilities offshore, and will be introduced in this section. 

Subsea production systems are an alternative development option for an offshore field. They are often a very cost effective means of exploiting small fields which are situated close to existing infrastructure, such as production platforms and pipelines. They may also be used in combination with floating production systems. 

Subsea production systems provide for large savings in manpower as they are unmanned facilities. However, these systems can be subject to very high opex from the well servicing and subsea intervention point of view as expensive vessels have to be mobilised to perform the work. As subsea systems become more reliable this opex will be reduced. 

Various types of subsea production systems are being used and their versatility and practicality is being demonstrated in both major and marginal fields throughout the world. 

As subsea production systems are remote from the host production facility there must be some type of system in place which allows personnel on the host facility to control and monitor the operation of the unmanned subsea system. 

The surface production system consists of a series of equipment items, such as that illustrated below, which shows the maximum oil handling capacity of the items. The maximum capacity of the system is determined by the component of the system with the smallest throughput capacity. 

The above example is a simple one, and it can be seen that the individual items form part of the chain in the production system, in which the items are dependent on each other. For example, the operating pressure and temperature of the separators will determine the inlet conditions for the export pump. System modelling may be performed to determine the impact of a change of conditions in one part of the process to the overall system performance. This involves linking together the mathematical simulation of the components, e.g. the reservoir simulation, tubing performance, process simulation, and pipeline behaviour programmes. In this way the dependencies can be modelled, and sensitivities can be performed as calculations prior to implementation. 

Breakdown and subsequent repair is clearly non-scheduled, but gives rise to nonavailability of the item. Some non-critical items may actually be maintained on a breakdown basis, as discussed in Section 11.3. Flowever, an item which is critical to keeping the production system operating will be designed and maintained to make the probability of breakdown very small, or may be backed up by a stand-by unit. 

Enhancements to the process may be required due to sub-optimal initial design of the equipment, or to implement new technology, or because an idea for improving the production system has emerged. De-bottlenecking would be an example of an... 

High Tena.city Sta.ple Fibers. When stronger staple fibers became marketable, the tire yam processes were adapted to suit the high productivity staple fiber processes. Improved staple fibers use a variant of the mixed modifier approach to reach 0.26 N /tex (3 gf/den). The full 0.4 N /tex (4.5 gf/den) potential of the chemistry is uimecessary for the target end uses and difficult to achieve on the regular staple production systems. 

The Courtaulds semicommercial production system is iUustrated in Figure 8. Dissolving-grade woodpulp is mixed into a paste with NMMO and passes through a high temperature dissolving unit to yield a clear viscous solution. This is filtered and spun into dilute NMMO whereupon the ceUulose fibers precipitate. These are washed and dried, and finally baled as staple or tow products as required by the market. The spin bath and wash Uquors are passed to solvent recovery systems which concentrate the NMMO to the level required for reuse in dissolution. 

A. A. Nichiporovich, Photosynthesis of Productive Systems, Israel Program for Scientific Translations, Jemsalem, Israel, 1967. 

Therapeutics. Therapeutic materials represent a class of polypeptides that are a low volume, high value product. The production system need not be very efficient but the quaHty of the recombinant protein has to be extremely pure (33,34). Thus high cost mammalian production systems can be tolerated. However, some of the therapeutic proteins such as insulin, human growth hormone, interleukins, interferon, and streptokinase are produced microbially. 

From the standpoint of a military product, system effectiveness is the probabiUty that the system meets successfully an operational demand within a given time when operating under specified conditions. From the standpoint of commercial products, system effectiveness is harder to define, but basically means customer satisfaction. There are several system parameters that are important to the customer. Some of these parameters are defined below. 

The decomposition kinetics of an organic peroxide, as judged by 10-h HLT, largely determines the suitabiUty of a particular peroxide initiator in an end use appHcation (22). Other important factors ate melting point, solubiUty, cost, safety, efficiency, necessity for refrigerated storage and shipment, compatibihty with production systems, effects on the finished product, and potential for activation. 

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