克拉玛依油田二厂八区套管破损机制研究

Research on casing damage mechanism of No.8 block of No.2 plant in Karamay oilfield

克拉玛依油田二厂八区井区经过长期开采出现了大量的套管破损问题。对套管破损位置进行总结归纳发现,套管破损主要存在于白垩系吐谷鲁群、侏罗系齐古组、二叠系乌尔禾组等地层中。对研究区连井进行地层对比、地震数据体进行波阻抗反演和砂体分析,发现研究区内白垩系吐谷鲁群和侏罗系齐古组的砂体十分发育,广泛存在于整套地层中。砂体中流体的渗流作用对套管的腐蚀为套管破损的主要因素。泥岩吸水蠕变膨胀、油层出砂和固井质量不合格为套管破损的其他因素。

A lot casing failures have occurred after long-term production in No.8 block of No.2 plant in Karamay oilfield.The summary of casing damage locations indicates that casing damage is mainly found in the Cretaceous Tugulu Group,the Jurassic Qigu Formation and the Permian Urho Formation.Based on the stratigraphic correlation of the wells in the study area,seismic acoustic impedance inversion and the sand body analysis,it was found that the sand bodies are well developed and widely occurred in the Cretaceous Tugulu Group and the Jurassic Qigu Formation.In the sand bodies,corrosion of casing by seepage of fluid is the main factor of the casing damage.In addition,mudstone expansion after water absorption,oil sand production and cementation quality failure are other factors causing casing damage.