An Approach Using Combined TLP With Fixed Platforms In Developing China Shelf Oil & Gas Field

The development of oil and gas field has reached a new stage with the substantial increase of oil price in recent years and with the increasing demand on the economical development of the field. The use of the combined tension leg platform with tender assisted drilling and fixed platforms has once again attracted the industry attention. It has been used in recent large oil field development in West Africa. This combined system has many advantages in developing China oil & gas fields in shelf area. For the areas lack of infrastructure, such as pipelines, this approach provides the flexibility in drilling, processing, production, oil storage, and future development in nearby areas. At shelf area, the water depth typically can change significantly from shallow water to relative deeper water. Fixed platform(s) can be used in shallow water area. For deepwater area, the cost of fixed platform can increase substantially. Tension leg platform can be used in the relative deeper water for drilling and initial processing, and then export the oil and gas to the fixed platform for production processing. This approach can produce substantial economic results in the shelf oil & gas field development. In South China Sea, there are many shelf areas with dramatic changes of water depth. This approach can be chosen to efficiently develop the field. If other support system is also used, such as FPSO exporting system, and tender vessel for assisting TLP drilling, it will provide more efficient field development means. This paper will explore the potential application of tension leg platform combined with fixed platform(s) in China oil field development. The advantages and technical difficulties for each system will be addressed. The paper will also address some successful examples of using the approach by industry and some technical issues encountered during the practice.