| oil |
Wash Tank Pilot (The Wash Tank pilot was created with the goal of optimising design and gaining a detailed understanding of the mechanisms of "Hull Process Tank" (HPT) separators, which are to be installed in the FPSOs of ongoing projects in the Gulf of Guinea. The pilot, with its groundbreaking measurement system, recreates the operating conditions of a real separator: it replicates, for each project, the emulsion that is expected to be created during production. The pilot's design takes these different objectives into consideration. Its key component is a 6-metrehigh column in which oil/water separation takes place continuously. The water content profile in the column is permanently monitored by a set of ultrasonic transducers, which also regulate the oil/water interface, the height of which remains constant throughout one experimental cycle. It is also possible to take a sample of the column's contents (fig. 3) at 25-cm intervals, for more precise measurements of the water concentration and of particle size distribution. The pilot operates as a closed-loop system. The oil and the water are pumped at a specified rate and mixed continuously under heavy shearing so as to form an emulsion in which the size of the individual drops can be controlled. The emulsion is considered to be representative of field conditions. It is separated in the column, after which the oil and water are recirculated towards their respective storage vessels. In this configuration, the system can continue to function for longer times (several days) and achieve steady-state operation in terms of quality of the oil produced and stabilisation of the interface. This is a particularly flexible pilot, since the whole range of variables relevant to separation can be scanned: temperature, oil flow-rate, BSW2, nature of the water and emulsion droplet size. Tests for a given field can last up to two months, depending on the series of tests proposed by the project. ixtra) |
