58- www. world- petroleum. org 5.2- Technology: pushing boundaries Serpas, an engineering manager at US plat-form contractor J Ray McDermott, " the engi-neer needs to work closely with the fabrica-tor and installer, because the loading during the fabrication and installation phases can control a large portion of the design." Not all platforms are new. Old oil tank-ers are sometimes converted into floating, production, storage and offloading vessels. Or a rig that was designed for one field can be adapted for use at another. Reusing old equipment isn't easy: precision measuring using lasers is necessary to ensure that new bits of kit will fit properly, for instance. But it makes obvious financial sense. For one thing, it's usually cheaper. And, for another, it's generally much quicker than building something from scratch. Speed is important because reducing the time it takes to get the oil flowing has a significant bearing on the economics. Platforms on the move While transportation and installation usu-ally take less time than other aspects of a platform project, these phases are none-theless risky and costly. The original de-sign must take account of the tools that will be needed for the installation phase - in some cases, massive, ship- mounted der-rick cranes that must be booked years in advance; the world's largest semi- submersi-ble crane vessel, owned by marine contrac-tor Heerema, has a lifting capacity of 14,200 tonnes. Inadequate early planning can lead to costly rework, equipment availabil-ity problems and schedule delays, says Kirt Raymond, a general manager at J Ray. Often a platform, or part of one, will have to be shipped a considerable dis-tance, from fabrication yard to field, add-ing another layer of logistical complication. Thunder Horse's 60,000 tonne hull was constructed in South Korea. Anything but straightforward Installation methods vary, depending on the type of structure and its location. Take a fixed platform, for example: once the main structural component - the sub-structure, or jacket, arrives at its destina-tion, it is up- ended from a horizontal to ver-tical position and lowered to the bottom of the ocean. Then it is levelled and piles are driven through the legs of the jacket into the seafloor. Next, the topsides, or deck, are lifted into place and set on top of the piling. The pieces are connected and other opera-tions required to complete the structure are conducted. Finally, the drilling rig and other equipment modules are put in place. If it sounds straightforward, it's anything but. The sheer size and weight of these mas-sive structures add significantly to the diffi-culties involved in executing each of these steps, making platform design, construction and installation one of the world's most in-credible feats of engineering. ?? 19462009

59- www. energy- future. com Industry facts The hydrocarbon compound: the most versatile there is Crude oil is mainly made up of chains of carbon and hydrogen atoms called hydrocarbons. The chemical bonds that link these chains together can be broken up and linked in different ways. According to BP, the hydrocarbon compound is the most versatile on the chemical charts - able to make an estimated 2.5 million combinations. The flexibility of hydrocarbons allows refiners to turn undesirable oil products into more valuable ones. Longer, heavier molecules can be transformed into shorter, lighter ones through a process called cracking, which uses temperature or catalysts to make new combinations of carbon and hydrogen atoms - and yield greater volumes of high- value products, such as gasoline. © Repsol