| Popis: |
Restriction or blockage of flow path due to waxy deposits is a global issue in the oil and gas production. This undesirable flow assurance issue leads to increase in production deferment and OPEX for mitigation and frequent intervention. It may also result in huge CAPEX for pipeline sections replacement due to untreatable blockages. Despite the current prevention and mitigation strategies in place, wax deposition cannot be fully eliminated. Existing remediation technologies can be broadly classified to mechanical, thermal, and chemical-based treatments. These also have some limitations such as availability, cost, deferment and effectiveness. Today, most effective solutions are often a combination of mechanical and chemical which are expensive in terms of cost and may result in additional deferment time. As such, the development of more effective remediation strategies is of great importance. Solvent-based cleaning can be relatively less expensive if it is a viable option. However, experience suggests that conventional solvents such as xylene are generally not that effective in dissolving and breaking wide range of waxy deposits with varying compositions. Enhanced solvent-based remediation is a novel approach with the focus to balance performance, cost, and safety for field applications. Based on this approach, understanding the field deposit, optimizing solvent's performance in the lab under representative field conditions, selecting a solvent that balances performance with cost and safety, scaling up from lab to the field conditions based on the field's limitations, and proper deployment of the selected solvent in the field play important roles in effective remediation of deposits. In this work, the enhanced solvent-based remediation approach and the lab procedure for primary screening of solvents are described. In addition, the procedure for cleaning a flowline that was restricted by wax deposit in an onshore field in South-East Asia is explained. The results of this successful field application that led to increase in net oil production and OPEX saving are also discussed. |
