油基钻井液用冲洗液BCS-020L研制及应用

油基钻井液完钻井井壁及套管壁上附着的油浆、油膜会影响固井界面的胶结性能。为了改善水泥环与环空界面的亲合性，提高界面胶结强度，研发了BCS-020L冲洗液体系。实验结果表明，BCS-020L冲洗液与钻井液、隔离液均有较好的相容性，对井壁和套管壁上附着的油基钻井液具有良好的冲洗效果，冲洗效率达到80%以上；对环空界面具有良好的润湿改性作用，可以有效促进水泥环与环空界面的胶结。该冲洗液体系在玉门油田柳平1井取得成功应用，固井质量优良。

Research and application of flushing fluid BCS-020L for oil-based drilling fluid cleaning

For drilling with oil-based mud, the oil slurry and film attached on wellbore or casing wall affect severely the cementing quality of the interface. To improve the compatibility between cement sheath and well surfaces, as well as increase the interface cementing quality, a preflush system BCS-020L was developed. The BCS-020L provides good compatibility with drilling mud and spacer fluid, and can effectively remove the oil-based drilling mud attached to the well and casing wall, with high cleaning efficiency, higher than 80%. Also, the BCS-020L could change cementing interface effectively from oil wet to water wet, and improve the cementing quality of interface efficiently. The preflush system BCS-010L has been successfully applied on Well LIUPING 1 in Yumen Oilfield with excellent cementing quality.