In this chapter, a broad technical overview is offered to illustrate the technological advancements that have made the original direct hydraulic system reach those system design features that are shown in figure overleaf, which is a modern general arrangement of the “multiplexing” type of the BOP control system. Behind each discrete advancement, it goes without saying, there was a lot of design work, influenced by the radically different conditions in the subsea marine environment than those that we experience on land. Each step of this enabling technology is reviewed with in-depth reasoning explaining the “whys” and “wherefores” of each particular development. Let us start, as the drilling industry did for the development of BOP designs, at the beginning of the industry’s step offshore around 60 years ago. Not least, it should be emphasized that the ways in which the systems’ architecture has evolved have, in large part, been “driven” by the statutes laid out by the American Petroleum Institute (API) and later by other class societies that govern design compliance within the industry. The learning objectives of this chapter are to provide factual insights into evolving BOP control system designs as the industry moved from onshore to offshore and subsequently from bottom-supported drilling installations to floating drilling installations. This technology also forms the basis of the underpinning principles of hydraulic/electro and multiplexing subsea control systems that are currently used in the control of all kinds of production trees, subsea production centers, subsea distribution, and pipe line end manifolds (PLEMs). This chapter can be considered as a foundation and introductory overview for the development of control systems used in the subsea environment and those engineering challenges and obstacles that have been successfully surmounted, resulting in the technology basis in use today in the manufacture of subsea control systems.
Part of the book: Drilling