Hydrates amass beneath and around production equipment and can form in hydrocarbon-seawater jets/plumes. The sources of hydrocarbons in these hydrates are natural seeps or temporary production system leaks. In this paper, some of (i) the formation parameters for these hydrates and (ii) the impacts on normal production operations and hydrocarbon-spill capture systems are discussed. Experience to date indicates that (1) m areas with reservoir hydrates, management of external hydrates can contribute to mudline equipment and wellbore stability, (2) in areas with natural gas seeps, hydrate accumulations that could interfere with installation and operation activities can be prevented, and (3) in areas with natural gas seeps, hydrates accumulate on production equipment where the seawater flow is bounded or semi bounded and do not accumulate where the flow is unbounded. This is evident from the sharp contrast in hydrate accumulation amounts on production equipment shown in Figure 6 (a) zero hydrate accumulation on vertical surfaces exposed to ocean currents and (b) hydrate accumulations to CAOSH on production equipment surfaces in bounded or semi-bounded locations somewhat protected from ocean currents. In the bounded and semi bounded locations, the dissolved gas concentration in the seawater can increase with time to levels many times that normally in unbounded seawater. At 40 °F and 2200 psi, the increased dissolved gas concentration level necessary to enter the hydrate region is more than 5 orders of magnitude greater that normally present in unbounded seawater. In the National Energy Technology Laboratory (NETL) tests, hydrate formation was not observed on solitary bubbles m tests at 40 °F and 2200 psi with the 3-CM natural gas at concentrations outside and inside the hydrate region during the observation tune periods (more than 2 mm for one of the tests in the hydrate region). Plume model calculations indicate that hydrate formation in unbounded plumes requires high leak rates, small source bubble diameters, and more than 5 m of plume rise above the source. Source fluids in such plumes will rise 5 m in less than 0.5 min, which is shorter than the observation time without hydrates at NETL. The results of the SwRI plume tests enhance our understanding of hydrate formation on production equipment and in seawater bounded capture systems. These tests allow replication of earlier capture system performance and a better understanding of failure mechanisms, both of which are important steps in developing systems and processes suitable for avoiding hydrate blockages and successfully capturing hydrocarbon leaks. The conclusions above suggest (i) a low probability of hydrate formation in the first 5 m of an unbounded plume and (ii) a very high probability of hydrate formation in deepwater bounded systems, in which the seawater phase or the seawater temperature and dissolved gas concentration are not limited or controlled adequately.