Development of deep offshore fields is costly. As such, accurate information is required before a decision can be made on the feasibility of prospect development. Such sets of information include the reservoir fluid characterization and flow assurance data. The subject of this paper is to demonstrate the importance of accurate and representative fluid characterization and resulting flow assurance data on optimum facility and production method design for development of offshore fields.
In this study, fluid characteristics and flow assurance aspects of a live waxy crude oil from offshore West Africa is investigated. Experimental work included determination of the wax appearance temperature (WAT) and rheological studies which included pour point, gel strength, and shear-dependent viscosity measurements under both dead and live oil conditions. The wax deposition tendency of the dead crude oil was also investigated. The experimental data were used for a case study to demonstrate the effect of live oil data versus dead oil data on the subsea system design and operating procedures.
The case study indicated if dead oil data was utilized, the subsea system design and operating procedures would be considerably more conservative than if live oil data was the basis of the design. For a marginal field, these differences could be the difference between an economical field and an abandoned field.