Research On The Characteristics Of Dilatation And Deformation Of Layered Rock Salt Storage

Now salt rock is considered as a perfect medium for underground oil and gas storage. Energy conjuncture is obviously, energy storage become more and more vital. There are many advantaged factors such as high safety on deeply space as a medium for energy storage. Considering the characters of salt rock that there are plentiful impurity and mudstone interlayer in the salt mines in China, and deep underground salt rock mass is layered, salt rock mass has the properties of layered structure, the deformation and the intensive properties different from common rock. Numerical simulation and theoretic analysis on the mechanical aspects of salt rock and layered salt rock and mudstone were conducted in the dissertation. In this paper the results of the study on salt rock and layered salt rock in the past were discussed, the existing problems of deformability and dilatancy of salt rock were considered, and the research in the following aspects was carried out:1. Using the software FLAC3D, numerical simulations on the creep properties of rock salt with mudstone interlayers under constant inner pressure were carried out and the effect on deformability and dilatancy was analyzed with different parameters of both soft and hard mudstone interbeds, and dilatation parts and size of salt rock were evaluated through density change.2. The top and bottom stresses of the storage tend to be larger; along the cavern outward the stress decreases gradually. In the interbedds and at the joints of cone and hemispheres of the cavern nonuniform distribution of stress often arises.3. The inside-pressure of the storage has a very important role on the deformation of salt rock. In satisfying within the upper limit and lower limit of the internal pressure of the storage, the convergence rate of the storage can be significantly limited when the internal pressure increases. Because the underground internal pressure is actually not constant, different numerical models with different internal pressures of the storage were utilized in the paper. Decreasing the internal pressure in the storage, the restrain is decreased, the deformation rate of surrounding salt rock is higher; increasing the internal pressure of the storage, the deformation rate of salt rock is lower.