Optimisation of Sand Control Technique for Offshore Heavy Oil and Unconsolidated Sandstone Reservoir: Case Study from Bohai Bay

摘要

As conventional hydrocarbon resources in current basins of the world continue to decline, heavy oil becomes a significant candidate to fulfill the world’s thirst for energy. In China, the potential reserves of heavy oil amount to 220 billion BOE, with more than 13% in offshore fields. For Bohai Bay, up to 80% of developed reservoirs are heavy oil and unconsolidated sandstone reservoirs. Due to the geological process and depositional environment in generating heavy oil, the common characteristics of such oils are high viscosity, low gravity, high asphaltenes, and weak homogeneity and cementation. As a result, the productivity of heavy oil is usually low in a single well, accompanied with sand production. In recent years, the sand control customization technology and single well precise design based on single formation was developed to optimize deliverability of single formation. The optimized sand control technique has become one of the major methods for increasing and stabilizing production in Bohai Bay offshore oilfield. This paper begins with an introduction of the application and limitations of traditional sand control methods in Bohai Bay offshore oilfield. Then, to meet the requirement of further enhancing oil recovery, sand management and proper sand control completion technology are introduced. After the experiment was conducted, the results of sand control were obtained from most oilfields. However, bad results of application still existed in some oilfields.