新型水基钻井液SMB的室内研究与初步应用

Study and Application of A New Water Base Mud SMB

南海北部湾涠洲油田涠州组二段、流沙港组二段硬脆性泥页岩水敏性极强,地层极易坍塌,严重阻碍了钻井速率的提高。从大面积开发该地区考虑,以甲基葡萄糖甙及硅酸盐作主处理剂,并复配使用成膜封堵剂和防塌剂,结合现场材料及条件,研制出了具有防塌、润滑、环保和储层保护等多功能的水基钻井液———SMB体系。室内试验评价了该体系的性能,结果表明其具有滤失量低、泥饼致密、流变性、热稳定性和润滑性好等特点以及一定的抗盐、岩屑、水泥、膨润土污染能力,其抑制性可与油基钻井液媲美。SMB体系在W6-9-3井进行了试验应用,应用井段未出现明显井垮、井漏事故。SMB体系经资质单位检测无毒,符合环保要求,适用于海洋钻探施工。提出了该钻井液在应用过程中应注意的问题及今后应改进的地方。

The brittle shales in the WEIZHOU II and LIUSAHGANG II in the Beibu Gulf oilfield is quite water-sensitive and bore hole caving and sloughing occurred frequently in the past.A drilling fluid,SMB containing methyl glucoside and silicate was proposed to deal with the hole instability problem.Lab experiments showed that this mud has low filtration rate,produces tough and impervious mud cake,and stable rheology,temperature property,good lubricity,salt tolerance,and contamination tolerance.The inhibitive capacity of this mud is as good as that of oil base mud.Field application of this mud in Well W6-9-3 was very successful.Examination of mud toxicity gave very satisfactory results,and can be used in offshore drilling.Some shortages of this mud that needs improvement were also discussed in this paper.