套管柱井口提拉力计算方法

Calculation Method of the Force That Wellhead Equipment Exerts on Casing String

套管柱井口提拉力的大小，直接影响井内悬空段套管和井口装置的受力，对此，国内外已发表多篇论文，但考虑的因素都不够全面，也较为保守．本文通过对影响井内悬空段套管受力状态各主要因素的分析，根据直立管柱稳定性理论和强度理论，把悬空段套管柱分成受拉段和受压段，推导出了井口提拉力的计算式．分析表明，温度变化对套管柱提拉力的影响举足轻重，地基沉降不容忽视．

Some papers have been published on the calculation of the force. But in these papers, the factors affecting the force are not completely considered, and the calculated result is in the side of safety. The author analyses comprehensively the factors, and based on pole stability and strength theories, a formula for calculating the force is derived. In the derivation of the formula, the poem party of casing string is divided into tensed segment and compressed segment, and this makes calculated result more practical. The calculation result of an example shows that the effect of downhole temperature change on the force is great, and that the effect of wellhead foundation setting is also not negligible.