Research On Fluid Transportation Of Bottom-Hole Of Oil Shale And Its Laboratory Bench Design

With the high-speed development of national economy, the energy source consumption was staggeringly to growth. The supply-demand relationship of oil and gas becomes imbalance. Because of the development of national economy, it is an urgent need for unconventional oil-gas source to be explored and developed. Domestic oil shale development made clearly that only higher oil content was exploited by commercial exploitation. And most of the difficult development of the high-pressure, low oil content of oil shale, while also has mining potential. It must be based on advanced technology to make "hard extraction" of the oil shale resources into "recoverable" oil shale resources. Therefore, it was thought that the Bore Hydraulic Mining Technology was considered to be the new cost-effective method.Bore Hydraulic Mining Technology called BHM for short. As an important part of mining technology, it was an advanced technology combined with water jet broken rock, the fluid particles pumping from the borehole bottom and continuous obtaining rock cuttings-sample into system.This paper supported by the project of "the cooperation and innovation projects of oil shale exploration and development of production and research", undertaken by Construction Engineering College. The particle-flow of the hole bottom which was formed by BHM was the start of research. Then, for the drilling requirements, it needed to study of particle-flow including of the field velocity, pressure, nozzle diameter, and the distance of nozzle to suction-port and so on. It aimed to resolve oil shale transporting problems of bottom particle-flow by BHM. The main research and conclusions were as following:1. Particle-fluid dynamic parameters of BHM was studied by the mathematical theory. The computational model was fit for BHM, which was derived based on the pressure and velocity. 2. Particle-flow field was simulated by CFD software, through the establishment of appropriate physical models and mathematical equations combined with the characteristic of BHM. It truly showed the flow forms and flow performance. Furthermore structure characteristics was comprehended by the flow forms and flow performance of the particle-flow field. Finally it revealed the effect of fluid dynamics parameters of the particle-flow field including diameter of nozzle and the distance between nozzle and pumping rim and so on.(1) When the nozzle diameter was 10mm, it showed that larger jet velocity larger influence of the bottom of particle-flow field. The jet velocity chose 200m/s more appropriate.(2) When the jet velocity was 200m/s, result showed the pressure of high pressure pump needed over 50MPa. If the compression strength of oil shale was 30MPa, the high pressure pump must was not less than 55MPa.(3) The distance between nozzle and pumping rim was moderately. The nozzle put at the same horizontal direction as the pumping rim may as well.(4) Nozzle diameter needed as small as possible, but considering of working life and material quality of nozzle, it should choose 10mm.3. The simulated data for the reference test-bed design. The experimental table should be used 70MPa high-pressure pump,10mm nozzle and hydraulic cylinders should be selected more than 700kN thrust.4. In short, the better fluid dynamics parameters was jet velocity 200m/s, high pressure pump 55MPa and nozzle diameter 10mm in the space size of 20m*10m.At present, fluid dynamics parameters were still stay at the level of theoretical derivation and numerical simulation. They should be modified by experimentation of indoor and geological exploration and drilling of field. Above-mentioned content of study was only about oil shale BHM technique, which was confined BHM to exploit oil shale. And fundamental research investigated the fluid dynamics of the particle-flow field. It was thought that farther, general and larger work was needed to exploit oil shale by BHM.