Comprehensive Application Of Fractal Theory To The Engineering Of Water-Sealed Oil Tank In Qingdao

Petroleum, which is a kind of strategic resource more than the only energy, isvital to a country's economic safety, so it is called "industrial blood". As one of themethods of preserving petroleum supply, strategic petroleum reserves is a veryimportant part in the country's strategy for energetic safety. Underground water-sealedstorage depot, which has been a new method of oil store after the World War II, isgenerally adopted by different countries, because it can cover less land, save morematerials and cost, etc. Now, in China, this new method is being tried out in pursuit ofpetroleum storage. Therefore, the site selection, survey and evaluation for petroleumstorage depot are the must in the new method.This thesis, which makes a project of underground water-sealed storage depot inHuangdao, Qingdao City as the object, adopting abundant statistics and testing data,has a close analysis to the principle of underground water-sealed petroleum storagedepot, and the hydro-geological and engineering geological condition of reservoir area.Moreover, the thesis, adopting a new theory – fractal theory, has a deeper analysis tothe geological conditions, including the quality and permeability of rock mass inreservoir area, which influence building the depot, leading the following findings:1. The main risk to underground water-sealed storage depot lies in the geologicalconditions, which must have hard and stable rock mass and as well as stableunderground water level.2. The quality of rock mass in reservoir area is evaluated with fractal theory. Fractaldimension D indicates the development of rock mass' joint fissure. It is concludedthrough analyzing that, the fractal dimension D of the rock mass quality is from 0 to0.60, indicating the good quality of the rock mass. And, the more developed rockmass' joint fissure is, the lower rock mass quality RQD is, and the higher the fractaldimension D is. It has the inversely-proportional relationship between the fractaldimension D and embedded depth. The relationship between the fractal dimension Dand rock mass quality RQD is set up in the thesis finally.3. It is found through analyzing that, the speed of longitudinal wave V pm, whichindicates the completeness of rock mass, has exact linear relationship with the fractaldimension D, that is, the more complete rock mass is, the higher the speed oflongitudinal wave V pm is, and the lower the fractal dimension D is.4. It explores the regularities of joint fissure distribution in reservoir area, and thepermeability of rock mass with fractal theory, finding that, the permeability of rockmass has exact linear relationship with fractal dimension D, which indicates the gradeof rock fragmentation. The lower embedded depth is, the heavier rock massweathering is, the more developed joint fissure is, and the higher fractal dimension Dis, thus, the stronger the permeability of rock mass is, and vice versa.