Research on the Evaluation of Flow Assurance Techniques for Offshore Heavy Oil Testing

Testing work is the foundation of oil and gas well development, and accurate evaluation of reservoir productivity can guide development activities. In offshore heavy oil well testing, due to the presence of cold seawater environments, accurate assessment of reservoir production is not possible without flow assurance measures. The widely used flow assurance measures for offshore heavy oil testing mainly include heating and insulation. However, the selection criteria for processes under different water depths are not yet clear. In this paper, based on the basic principles of heat transfer, temperature field models of heavy oil well testing under deep and shallow water environments are established. The models are used to analyze the effects of single and combined flow assurance measures on temperature distribution in deep and shallow water heavy oil well testing. The main parameters analyzed include: heating power and depth, thermal conductivity of insulation tubes, and depth of insulation tube installation. Through analysis of the calculation results, it is found that in shallow water environments, both heating and insulation measures can ensure that the wellbore temperature is higher than the inflection point temperature of the heavy oil, but the insulation measure has a greater effect. In deep-water environments, a single heating measure cannot guarantee that the wellbore temperature exceeds the inflection point temperature of the heavy oil, and insulation measures need to increase the insulation depth to be feasible. The combination of both measures is much more effective than a single measure. The deeper the heating and insulation depths, the higher the wellbore temperature distribution, but there is a limit to the heating depth, while there is no limit to the insulation depth. The research results can provide theoretical guidance and reference for the selection of flow assurance processes for offshore heavy oil testing.