基于Abaqus的软硬交错地层钻进过程仿真及动态特性分析

Drilling process simulation and dynamic characteristic analysis ofsoft-hard-staggered strata based on Abaqus

随着钻探技术向深部地层发展,研究钻进过程中钻头与深部复杂地层的动态特性及参数响应规律成为研究中的重难点。采用数值模拟和响应面分析相结合的方法,研究了聚晶金刚石复合片(PDC)钻头与典型复合地层在钻进破坏过程中的动力学特性,并对其进行了参数分析;以带倾角的软硬交错地层作为典型复杂地层为研究对象,基于Abaqus建立了全真尺寸的PDC钻头与软硬交错地层之间的动态破坏有限元仿真模型,得出了钻头在钻进过程中受到地层反力的动态特性;通过正交试验进行了数值仿真试验,研究了在不同的地层参数及钻进参数下PDC钻头的动力学特性;采用单一因素分析法和响应面分析法对钻进参数及地层参数与钻头受到地层反力之间的关系进行了建模与辨识,得到了多参数下钻头受到的地层反力变化趋势及回归模型。研究结果表明:软硬地层倾角越大,钻头受到的地层反力平均值和冲击峰值亦越大。随着地层软硬程度比的增大,钻头受到的平均反力和峰值反力大幅增长。在一定范围内,增大转速会降低钻头受到的反力冲击。研究成果可以为深部复杂地层钻进时钻头反力的预测提供依据,同时对深部复杂地层钻进轨迹控制起指导作用,对地质深部钻进有重要意义。

[Objective]With the development of drilling technology for deep strata,the study of the dynamic characteristics and parametric response law of drill bits and deep complex strata during drilling has become a key and difficult point in research.[Methods]In this paper,a combination of numerical simulation and response surface analysis was used to study the dynamic characteristics of PDC bits and typical complex strata in the drilling process,and parametric analysis was carried out.In this paper,soft-hard-staggered strata with dip angles as a typical complex formation were studied,the dynamic damage finite element simulation model between the PDC drill bit and the soft-hard-staggered strata with the full real size was established based on Abaqus,and the dynamic characteristics of the drill bit subjected to the reaction force of the strata during drilling were derived.Numerical simulation experiments were also conducted by orthogonal tests to investigate the dynamic characteristics of the PDC bit under different formation parameters and drilling parameters.[Results]The single factor analysis and response surface analysis were used to model and identify the relationship between drilling parameters and stratigraphic parameters and the reaction force on the drill bit by the stratum and to obtain the changing trend and regression model of the reaction force on the drill bit by the stratum under multiple parameters.The results showed that the higher the inclination angle of soft-hard-staggered strata,the higher the average value and peak impact value of the bit subjected to the stratigraphic reaction force.The larger the ratio of softness to the hardness of the strata is,the larger the average and peak reaction forces on the drill bit.Within a certain range,increasing the rotational speed will reduce the impact of the reaction force on the drill bit.[Conclusion]The research results provide a basis for predicting the bit reaction force during drilling in deep and complex formations and guide the control of the drilling trajectory in deep and complex formations,which is of great significance for deep geological drilling.