海上固井紧凑型多级泡沫水泥浆发生器优化设计及试验分析OA

In the process of offshore oil,gas and hydrate development,the shallow strata face dual risks of fluid invasion and lost circulation during cementing operations.As a low-density cement slurry system,foamed cement slurry exhibits promising application prospects in addressing lost circulation and improving cementing quality through large-displacement operations.However,existing foamed slurry cementing equipment is bulky,and the density fluctuates significantly during the mixing process of the generator,which makes the way to achieve the equipment miniaturization while improving the mixing efficiency a research focus.In this paper,three new types of foamed cement slurry generator structures are designed,namely jet orifice plate type,external intake type and internal intake type.Then,based on CFD numerical simulation,the structural parameters are optimized.Finally,a principle prototype is developed,and tested under various working conditions for evaluation.The following results are obtained.First,the principle prototype of compact multistage foamed cement slurry generator which integrates jet collision,curved pipes and static spoiler can produce foamed cement slurry with densities ranging from 800 to 1 500 kg/m3.Second,in the process of pressurized slurry preparation,the density control accuracy of the foamed cement slurry is high,with the average density error within±10 kg/m3 of the target value,and the density can reach the target within a 2%-5%error margin in as fast as 10 seconds.Third,when the gas content is slightly higher than 30%,the density fluctuation of the foamed cement slurry can still be controlled within±30 kg/m3 range,and the slurry preparation process is stable with small pressure fluctuation and strong self-feedback regulation ability.In conclusion,this study enables the rapid and uniform preparation of foamed cement slurry under varying pressure and flow rate conditions,meeting the demand for miniaturized and efficient equipment on offshore platforms,and is of great significance for the localization of offshore foamed slurry cementing equipment.