TABLE OF CONTENTS The development of offshore fields usually involves the construction of a structure at a central location that acts as the gathering and control center for several wells that can be a number of miles away. Such a platform plays several roles. For example, with the advent of directional drilling, modern platforms are also used to drill into a field. The drill holes spread out radially from the platform, often extending several miles to reach a particular location in the reservoir. The platform houses the hydraulic equipment that provides power to operate various valves located in trees sitting on top of wells on the sea floor. It also holds hydraulic equipment that controls the well flow and, when required, high pressure pumps used to pump water or gas back into the formation to enhance oil recovery. High pressure flowlines bring the hydrocarbons from the wells to the platform. Hydrocarbons come out of the ground as a high pressure mixture of oil, gas, water and solids. Platform-based equipment processes the mixture lowering the pressure, separating oil and gas, and extracting water, sand and other substances. Processing must be conducted in a carefully controlled manner. For example, lowering the pressure of a gas-rich flow by choking drops its temperature, turning the gas into a liquid, or worse, into a snow-like hydrate. Hydrates can plug a flowline, as they consist of methane trapped in icy crystals. Accordingly, provisions must be taken to heat up...
