The first domestic field test of salt cavern nitrogen gasification cavity was successful

- Sep 18, 2018-

On August 15th, the analysis and interpretation of the sonar data of the JK7-1 salt cavern gas storage well completed by the Jiangsu Gas Storage Branch of Huabei Oilfield showed that the technical indicators of this well all met the design requirements, marking the domestic salt cavern gas storage. The first field test of nitrogen gas barrier cavity was successfully carried out, which laid a technical foundation for the comprehensive application of nitrogen gas barrier cavity.


The nitrogen gas barrier cavity test is a major technical issue for PetroChina. Previously, domestic salt cavern gas storage chambers generally used diesel as a solvent, which was not only costly, but also difficult to separate oil and halogen, and there was a risk of environmental pollution. The biggest advantage of the nitrogen gas barrier cavity process is environmental friendliness, which can reduce the cost of cavity formation.


The nitrogen resisting solvent is replaced by nitrogen gas. Because of the compressibility of nitrogen, the gas-water interface is difficult to monitor during cavity formation. At the same time, the wellhead pressure of the solvent can reach about 13 MPa, and the wellhead and the downhole string are The air tightness is very high. The technical personnel of the Jiangsu Gas Storage Branch Company replaced the test wellhead seal and the downhole tubular string, carefully inspected and wiped each of the string seal threads during the pipe string entry process, and monitored the casing torque through the torque gauge. Downhole enters the permanent fiber optic interface instrument, and the gas-halogen interface is monitored by a combination of fiber optic interface and neutron logging. The above measures effectively solved the key problems of the downhole sealing and gas-water interface monitoring of the test well.


During the test, the key cavity parameters of the on-site monitoring were normal, and the nitrogen-halide interface control and cavity shape development met the design requirements. Through this field test, the site has formed a salt cavern gas storage tank nitrogen gas barrier cavity well installation process, cavity column entry process, fiber interface detector installation and testing process, gas and water interface monitoring and control, on-site matching note Key technologies such as nitrogen technology. In the next step, after the completion of the acceptance, the new salt cave gas storage well will be fully promoted.