WATER-SEALED RELIABILITY OF VERTICAL WATER CURTAIN SYSTEM IN UNDERGROUND OIL STORAGE CAVERN IN ISLAND ENVIRONMENT

Most of the underground water-sealed oil storage caverns in China are built in coastal areas and within the continental coastline. There are few studies about the construction of underground water-sealed oil storage cavern in island. Seawater surrounds the island, and the excavation of underground caverns can lead to seawater intrusion, affecting the service life of underground water-sealed oil storage cavern. In order to ensure the water-sealed reliability of underground cavern, it is necessary to arrange the water curtain system. Nowadays, underground water-sealed oil storage cavern is mostly equipped with horizontal water curtain system. There are few researches on water-sealed reliability of vertical water curtain system. Compared to horizontal water curtain system, vertical water curtain system has advantages of easy to drill and small disturbance on original rock. In addition, vertical water curtain system can weaken the seawater intrusion. Therefore, the study on water-sealed reliability of vertical water curtain system has great significance. In this paper, we use numerical simulation to research the arrangement methods of vertical water curtain system. According to the orthogonal design, we obtain the best arrangement parameters of the vertical water curtain boreholes. Based on the underground water-sealed oil storage cavern of an island in Zhejiang province, we study the water-sealed reliability of vertical water curtain system by comparing the results of cavern without water curtain system, cavern with horizontal water curtain system and cavern with vertical water curtain system. The results show that in the case of only setting vertical water curtain system, it can satisfy the water-sealed reliability. Moreover, compared with horizontal water curtain system, vertical water curtain system can better prevent the flow of oil from one cavern to another. The results provide theoretical basis for the water-sealed reliability of vertical water curtain system in underground water-sealed oil storage cavern in island environment.