基于球面波传播理论的钻头趋近邻井防碰预测模型

为实现丛式井地面防碰监测预警系统有效预测正钻井与邻井间距离的功能,建立了钻头趋近邻井防碰预测模型。该模型依据弹性波的球面扩散和衰减吸收理论,通过分析实测数据的幅值衰减规律而建立。利用该模型,通过地面实时监测、分析、计算风险邻井套管的振动信号特征,可求取钻头与邻井套管的距离,识别钻头碰撞邻井井筒的可能性并及时预警。根据渤海某油田的防碰监测数据,用所建模型计算出了监测井段钻头与邻井套管的距离;对比测井数据计算的井眼扫描距离和模型计算结果发现,利用该预测模型求解的钻头与邻井间的距离与测井数据得到的井间距离有明确的对应关系,表明所建模型可以作为丛式井地面防碰监测预警系统预测井间距离的一种计算方式。 

Anti-Collision Prediction Model for Drill Bit Approaching Adjacent Well Based on Spherical Wave Propagation Theory

In order to improve the effectiveness of anti-collision system in offshore cluster well drilling anti-collision prediction model of drill bit approaching adjacent well was built based on the theory of elastic waves in spherical spreading and absorption attenuation,and amplitude attenuation pattern analysis of actual measured data.Through adjacent well casing vibration monitoring and data processing,the distance between the drill bit and adjacent well casing can be calculated by using the model,and the chance of well collision can be identified and warning provided.The model was used to analyze the casing vibration signals of adjacent wells in Bohai Sea,and gave the distance between dill bit and adjacent well casing.The distance between drill bit and adjacent well casing calculated from the model and well distance from log data matched well.It demonstrated that the model can be used to predict the distance between drilling and adjacent well,which could provide a new technical support for safe drilling of offshore cluster wells.