浅层大位移井固井水泥浆体系研究

Research on cementing slurry system for shallow extended reach wells

K油田是渤海区域重点开发项目,该油田第三系地层中含油层位较多,勘探开发初期以浅层大位移井为主。浅部地层具有泥质胶结及压实情况较差、地层温度及压力较低的特点,固井作业时,水泥浆易向低压疏松地层中漏失,低温条件又会导致水泥浆水化作用慢、形成水泥石强度低,极大影响了固井质量和钻井安全性。针对这一问题,本文从降低水泥浆密度、提高水泥石强度、强化水泥浆体系稳定性三个角度,研发优选了低密度材料、新型早强剂及纳米增强剂,形成了一套适合渤海K油田浅层大位移井固井用水泥浆体系,经实验测定具有较好的性能,对该项目固井作业及后续开发具有重要意义。

K oilfield is a key development project in the Bohai Sea.There are many oil-bearing layers in the tertiary strata of the oilfield,and shallow large displacement wells are mainly used in the initial stage of exploration and development.Shallow formation is characterized by poor argillaceous cementation and compaction,low formation temperature and pressure.During cementing operation,cement slurry is easy to leak into low-pressure loose formation.Low temperature conditions will lead to slow hydration of cement slurry and low strength of cement stone,which greatly affects cementing quality and drilling safety.To solve this problem,this paper developed and optimized low-density materials,new early strength agents and nano reinforcements from the perspectives of reducing the density of cement slurry,improving the strength of cement paste and strengthening the stability of cement slurry system,and formed a set of cement slurry system suitable for cementing shallow extended reach wells in Bohai K oilfield.It has good performance through experimental measurement.It is of great significance to the cementing operation and subsequent development of the project.