There are numerous flow assurance and processing challenges associated with the production of heavy oil. These challenges are generally addressed in the early stage of the development and include; sizing of separators, internal design of the vessels, the process vessel configuration and the optimum means of handling solids and water. A critical aspect of the design is the accuracy and the reliability of the fluid characterization data. Numerous operators can attest to the difficulties in processing heavy oil and many make attempts to minimize the impact of these issues in the design stage. However, there are critical factors associated with produced fluid characterization data that are regularly either overlooked or misinterpreted. It is the importance of this data reliability and accurate interpretation that is the subject of this paper.
The high viscosity and low gravity of heavy oil is usually the principle concern of the design team in addressing process components and operational practices. However, there are numerous horror stories associated with flow assurance issues that should have been taken into consideration during detailed design. The impact of asphaltenes, paraffin, naphthenates, inorganic scale deposition and emulsion stability are a few of the more common challenges that can, and should, be addressed prior to detailed design. The impact of these constituents on processing and operations can make or break the economics of the development, particularly when taking into account the long-term OPEX associated with chemical treatment cost if these constituents are not adequately addressed.
In addition, brown field development of heavy oil and the subsequent processing through an existing infrastructure will create other challenges, especially if the existing production infrastructure is designed to handle mid and high API gravity crude.
By following some fairly rigorous, but necessary, guidelines on data accumulation and interpretation most if not all of these problems can adequately be addressed during detailed design and the development of operating procedures. Therefore a holistic approach in assessing the design of these facilities will be crucial to maintaining a low CAPEX and OPEX for processing heavy oil effectively. This paper aims to outline the different aspects associated with these challenges and will cover design, operation, monitoring and, where relevant, upgrades and retrofit issues.