水平井带扶正器套管接触方式及其对摩阻影响

Contact Forms of Casing with Centralizer and Its Effect on Friction

胡锡辉 李维 徐璧华 马旌伦 袁彬

HUXihui LIWei XUBihua MAJinglun YUANBin

中国石油西南油气田分公司, 四川 成都 610017 油气藏地质及开发工程国家重点实验室·西南石油大学, 四川 成都 610500

Southwest Oil and Gas Field Company, PetroChina, Chengdu, Sichuan 610017, China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China

下套管作业过程中，由于重力与井眼轨迹影响，将导致套管发生弯曲，与井壁发生接触，从而产生附加摩阻，当摩阻较大时会影响套管顺利下入。尤其是水平井为保证顶替效率和固井质量，下套管时加入了大量扶正器，扶正器的加入将增大套管的摩阻系数，从而给水平井下套管作业带来了更大的困难。针对这一问题，首先，提出套管与井壁有3种接触方式，即自由状态、点接触与线接触；并指出不同接触方式下产生的摩阻不同。然后，通过建立了套管在下入过程中的扰曲受力方程，以及套管与井壁接触方式判断模型；并根据该模型分段计算方式准确地计算出不同接触方式下套时的管摩阻。通过现场示例分析表明，该方法能准确预测摩阻，对现场计算摩阻具有很好的指导意义。

During the running casing operation, the casing will be bent and contact the well wall due to the influence of gravity and well trajectory. Therefore, an additional friction is generated, which affects running casing when it is too large. In particular, a large number of centralizers are used to ensure displacement efficiency and cementing quality in horizontal wells, which brings greater difficulties to running casing operations due to the increase of friction coefficient. Aiming to this problem, the paper first points out the three contact forms of the casing and the well wall:free state, point contact and line contact. It is also points out that the friction is different under different contact form. Then, the casing tortuous equation and contact from judgment model are built. According to the model segmentation calculation method, the friction of the casing under different contact modes is accurately calculated. The field example analysis shows that the method can accurately predict the friction and has a good guiding significance for calculating the friction.

10.11885/j.issn.1674-5086.2019.04.08.02