Research On Reservoir Protection Technology For Dazhangtuo Underground Gas Storage

The Dazhangtuo Underground Gas Storage lies to Dagang District of Tianjin Municipality. It is the first underground gas storage in China, an important supporting facility for the Shan-Jing Gas Transmission Project, which will be used to balance the seasonal changes of the consumption volume and ensure stable supply of gas to Beijing and Tianjin in case of emergency. The Dazhangtuo Underground Gas Storage will be of great significance in improving the air quality of the capital city. It is scheduled that 300x104m3/d of gas will be transmitted to Beijing in the winter of 2001.The Dazhangtuo Underground Gas Storage is to be constructed out of the Dazhangtuo oil and gas reservoir which was discovered in 1975. The plan is to drill 12 injection-producing wells, with a depth ranging from 2800-3000m.The reservoir protection technology for Dazhangtuo Underground Gas Storage is one of the pivotal technologies for building an underground gas storage. The innovative research is :1. It is firstly constructed under formation pressure coefficient 1.12 to 0.75, that reservoir protection technologies for building an underground gas storage out of an exhausted oil and gas reservoir. A series of the technologies includes the preparing technique, the field management of the drilling operations, the technique for drilling the pay zone, the cementing technique, the well testing technique, the evaluation technique.2.The screened temporary plugging technique is successfully utilized in the reservoir protection of Dazhangtuo Underground Gas Storage from an exhausted gas reservoir.3. It is firstly constructed that work procedures to run the production string of injection-producing wells for an underground gas storage in China.The reservoir protection technology for Dazhangtuo Underground Gas Storage is successful. It ensured stable supply of gas to Beijing and Tianjin in the winter of 2001.