Page 26: of Marine Technology Magazine (March 2017)
Oceanographic Instrumentation: Measurement, Process & Analysis
Fiber Optics friendly seawater. Despite operating in such adverse working a well-understood technology dating back 40 years and the conditions, a connector must be absolutely reliable throughout beginning of ? ber optics.
its design life of 25-30 years. During the last decade, alternative optical connectivity tech-
On one side of the equation, industry requires growing ? ber nologies have been developed and proved their reliability count, and on the other side lower cost and higher reliability. from both manufacturing and application perspectives. Some
The objective is to have a connector that is well-balanced be- approaches use a non-contacting interface to provide higher tween these seemingly “opposite” requirements. This is the durability and tolerance to rough handling, with a small pen- reason why FO connector designers continuously innovate in alty in optical performance. Others provide a high-density, terms of design and integrated optical technology. In the new multi-? ber connection to save space and weight for high-? ber- offshore oil and gas market environment, they are committed count systems, at the expense of some complexity at the con- to bringing FO connector capability and cost-effectiveness as necting interface and pre-alignment mechanism.
close to each other as possible. In another interesting connectivity technology development,
Drymate connectors are familiar to users of military/aero- a bare ? ber cleaved tip has been repackaged into a downhole space circular connectors. FO drymate connectors can be in- wetmate connector. This epoxy-free and ferrule-less technol- stalled either within a module or between modules that have ogy offers both greater tolerance to high temperature and a been assembled on-site. They are designed for topside mating lower-pro? le dimension in order to ? t into a tight downhole in an atmospheric environment, although they withstand sub- casing. Figure 2 shows FO wetmate connectors developed for sea water and pressures while mated. The standard coupling subsea trees and downhole applications.
of each half – ensuring sealing integrity of the mated pair; is Depending on the subsea and marine application and type performed manually via a threaded coupling ring. of sensing required, each of these optical-interface technolo-
In subsea FO wetmate technology, typi? ed in the second- gies has its place. The main challenge is to adapt these tech- generation HydraLight connector, the crucial ? ber-to-? ber nologies optimally, in order to create a cost-effective solution underwater union is accomplished while both halves of the meeting installation, deployment and maintenance needs.
FO termination are protected from contamination by seawa- Industry needs connectors to function reliably when in- ter, sand and silt, because the mating process occurs in an en- stalled subsea and downhole in a well for reservoir surveil- closed, separate, oil-? lled, pressure-balanced chamber. This lance and improved oil recovery. High-temperature wells pressure balancing system allows the connector to operate (e.g., >150°C), where electrical sensing systems face some without being affected by the pressure, in contrast to most limitations, were targeted early on for deployment of FO drymate connectors, which have to withstand pressure differ- sensing systems. Over the years, FO sensing gained interest ential due to having an atmospheric-pressure internal cavity. among operators, not only for the ability to withstand very
Smaller systems bene? t from ? ber optics. More compact, high temperatures, but also for the quality and the amount of lighter, highly modular subsea drilling and production systems data retrievable from the wells.
are the order of the day. They are easier and less expensive to Most operators introduce next-level FO capabilities as part install. Even though an optical ? ber weighs much less than of a natural progression in their ? eld development. As ma- a comparable copper wire, there are practical limits to how rine oil and gas exploration and production venture to ever- small a connector should be. A subsea wetmate connector that increasing depths, with consequently more robust ? ber-optic will be deployed by a remotely operated vehicle (ROV) must connector operating pressure and temperature requirements, be large enough to be clearly seen by ROV cameras, and suf- industry challenges evolve to keep pace, and a collaborative ? ciently robust to be mated/unmated without damage by ROV approach with customers and partners is key for subsea FO manipulators. In this case, ROV-mateable connectors may connectivity design. It is always desirable to exceed technical have generous lead-ins to guide the mating halves together. requirements, but it is much more important to exceed cus-
Connecting Traditional Packaging to Subsea Applications tomer expectations in term of cost, operability and reliability.
To a great extent, subsea ? ber optic connectors use new
Future Implications ways of packaging tried-and-true technologies, rather than radically new and unproven approaches. TE Connectivity Ma- Long transmission distances, high data rates, lightweight, rine Oil & Gas adapts technologies that were well-established small size, distributed sensing—? ber optics brings together so for telecom, network, aerospace and military applications many capabilities important to improve ef? ciency of marine to subsea applications. Subsea connector technology relies offshore exploration and production. The technological break- on ultra physical contact (UPC) and, more recently, angled throughs of optical ? ber connectivity can create a bright future physical contact (APC) for better performance (especially with the possibility of developing and producing with higher with sensing systems) of termini based on a ceramic ferrule, performance at lower cost and unlocking new resources.
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