Abstract:
It is in strong demand to construct the underground water-sealed oil storage in rock caverns, but there are problems such as difficult control of water seepage during the construction of water-sealed cavern storage, insufficient attention to the water sealing conditions of cavern storage, and immature methods for water sealing control at present. Herein, the water sealing criteria of cavern storage were analyzed by reviewing domestic and foreign researches on the water sealing of underground oil storage in rock caverns, and it was found that the vertical hydraulic gradient greater than 1 in the surrounding rock of caverns was the essential condition for the underground oil storage in rock caverns to meet the requirements of water sealing. Besides, it was also revealed that the goal of water sealing regulation in the cavern storage was to achieve the lowest full life cycle cost and the highest benefit under the premise of meeting the requirements of water sealing. Meanwhile, study was also carried out to the mechanism of different regulation means, such as seepage reduction by grouting, artificial water curtain system adjustment and cavern storage pressure adjustment. On this basis, the multi-factor combined regulation mechanism of water sealing in cavern storage was analyzed, and a multi-factor combined regulation strategy based on iterative optimization was proposed. Finally, the multi-factor combined regulation strategy based on iterative optimization was applied through case analysis. Generally, the research results could provide theoretical and technical support for the efficient construction and safe operation of cavern storage projects.