复杂断块油田钻井废弃物回注方案优选与工程实践

Drill Cuttings Reinjection in Complex Fault Block Oilfield:Layer Selection Scheme Optimization and Engineering Practice

针对浅海某油田钻井井筒废弃物(钻屑、钻井液以及含油污水等)处理困难的问题,在对油田地层具有断块复杂、断层众多等特点深入研究的基础上,论证了废弃物回注处理方案,形成了利用已有生产井以及实施专用回注井两种作业方案。通过对两种方案在层位选择、回注实施参数以及安全系数等方面考虑,最终选择钻探专用回注井,完钻后根据实测地层资料以及定向井数据对回注层位进行进一步筛选和优化。优选出上下具备良好的隔离层、能够满足浆体回注容量需要的层位,同时保证浆体不上窜地面以及不污染储层或其他层位。

Cuttings reinjection is becoming the effective technical means of waste disposal at sea,which involves the disposal of wellbore drilling cuttings,drilling fluid and oily sewage etc.For complex fault block oilfields,waste reinjection scheme selection is one of the most important contents.Based on the analysis on the reservoir geology,two reinjection schemes are proposed：using an existing production well,or constructing a reinjection well.Through comparative study on the two schemes in terms of layer selection,reinjection operation paramters and safety factors,it is determined to construct a new reinjection well.The reinjection layer is further selected and optimized according to the stratigraphic information and directional well data.Finally,the reinjection layer is obtained,which achieves good isolation and satisfies the need of slurry injection capacity,ensuring that slurry does not remain on the surface layer and not channeling reservoir pollution or other layers.