Testing to evaluate the potential of a new well or field is a common practice in the oil and gas industry. When performing this task in a deep-water environment, however, there are significantly more challenges for the operator and service company to address, and when testing a heavy oil reservoir, the challenges are even further exacerbated. Special consideration must be given to the following issues: 1. High rig rates associated with deep-water operations will make job problems more costly. 2. Producing heavy crude oil to surface, moving it through the surface production train, and finally, disposing of it in an environmentally acceptable manner. 3. Deep-water environment exposes the crude to an extended period of heat loss and low temperatures while it is in the landing string.In order for the well test to be effective, all the above conditions must be fully understood and methodology employed that will reduce the chance that operational risks will occur. This paper will discuss the successful testing of a heavy oil reservoir in deep water. A number of different ways to assist the production of heavy crude in the deep-water environment will be presented, and the relative merits and limitations of each will be considered. The discussion will provide an outline of the necessary additions to the surface production train and the use of chemicals and heat to ensure flow. Finally, it will consider what equipment is necessary to properly dispose of the produced fluid.The testing methods discussed in this paper can be applied to heavy-and low-pour-point crudes in deep water. The equipment and methods can also be used in shallow water applications or on land. The case history data will illustrate: 1. Why particular methods and equipment were used and why others were rejected.