侧钻水平井弯曲段套管抗挤强度研究

Research on the collapse strength of the bending section casing in sidetracking horizontal wells

根据侧钻水平井弯曲段套管受力特点,建立了套管抗挤强度计算模型,并采用能量法推导了套管在弯曲载荷作用下轴向变形及抗挤计算公式。在公式推导过程中考虑到了弯曲载荷对套管截面不圆度的影响。对吉林油田某侧钻水平井使用的套管进行模拟计算,并通过室内试验对计算值进行验证。结果表明,推导的公式具有较高计算精度,可以满足现场工程计算需要;轴向载荷对套管抗挤强度的影响较为显著,在实际生产过程中应严格控制。

According to the force characteristics of the bending section casing in sidetracking horizontal wells,the calculation model for casing collapse strength was established.The energy method was adopted to derive the calculation formula for the casing axial deformation and collapsing under the effect of bending load.The effect of bending load on the casing cross-section ellipticity was considered in the process of deriving the formula.The simulation calculation of casing used by some sidetracking horizontal well in Jilin Oilfield was conducted and the laboratory test of the calculation result was performed.The result showed that the formula derived had a relatively high precision.It could meet the needs of the field construction.The axial load had a remarkable effect on the casing collapse strength.It should be controlled severely in practical production.