海底松软地层取心钻头的设计与结构优化  

Structure design and optimization of coring bit for soft sea bottom

作　　者：冯帆[1] 万步炎[1] 黄筱军[1] 

机构地区：[1]湖南科技大学机电工程学院,湖南湘潭411100

出　　处：《机械设计》2016年第7期21-26,共6页Journal of Machine Design

基　　金：国家高新技术研究发展计划(863计划)资助项目(2012AA091301)

摘　　要：针对于海底松软地层取心困难,设计了一种新型海底底喷取心钻头,并进行了陆地钻进试验,初步验证了钻头的可行性。利用CFD软件对钻头孔底流场进行数值分析,得出了冲洗液平均上返速度。同时利用ANSYS进行流固耦合仿真,分析了钻头在海底加压钻进时的受力情况。以冲洗液最大上返速度与钻头最大应力为设计目标,以钻头水眼、水槽、隔水间隙的尺寸为设计变量,通过中心复合设计法生成试验所需的设计变量的样本点,对生成的样本点进行有限元分析得到样本点的响应点,借助最小二乘法建立近似模型二阶响应曲面。采用折中法建立多目标优化模型,并用遗传算法进行求解。结果表明,冲洗液上返速度上升7%,钻头最大应力降低13%。A new kind of coring bit for the soft sea bottom was designed aiming at the coring difficulties of soft sea bottom.The preliminary land drilling experiment was performed to test the feasibility of drill. The flow field of drill hole bottom for the sea bottom was simulated by CFD to obtain the washover average upward velocity. The fluid-solid coupling simulation was conducted by ANSYS to analysis the stress state of drill while pressure drilling in the sea bottom. Then, the maximum washover velocity and max drill stress was set as the design target. The size of hole, sink and impermeable gap of drill were set as the design variable. The required sample points of design variables were generated according to the central composite design method.The finite elements analysis was performed on the generated sample points to obtain the response sample points. The second-order response surface approximation model was established using the least square method. The eclectic method was adopted to establish multi-objective optimization model. The genetic algorithm was used to solve the problem. The results showed that the washover velocity raised by 5% and the max stress reduced by 10%.

关 键 词：钻头设计 流场 有限元分析 尺寸优化 

分 类 号：TE53[石油与天然气工程—油气田开发工程]