可钻型低频自激震荡脉动固井装置的研制与应用

Development and application of a drillable,low-frequency and self-excited vibration pulsing cementing unit

气井、小环空间隙等特殊井况下的固井质量缺陷在生产中常见,严重困扰了开发技术措施的实施。近年来,在提高气井固井质量的研究与应用上,能改善环空钻井液顶替效率和水泥浆性能的特殊固井装置备受关注。为此,基于流体自激震荡理论,结合模拟实验测试结果,优化设计并研制了一种井下大排量低频自激震荡方式的可钻型水力脉动发生装置:外径177.8mm,工作压差0.5～1.5MPa,工作排量25～30L/s,压力脉动输出频率约10Hz;连接结构采用圆螺纹套管接箍卡装方式;牙轮钻头、PDC钻头易钻。并在四川盆地安岳区块φ177.8mm尾管固井中得到成功试验与应用,结果表明,该装置工作稳定可靠,固井质量显著提高。该装置首次被应用于井眼待继续加深的中间套管固井,拓展了振动固井技术在提高油气井固井质量中的工程应用范围。

Cementing-related problems frequently occur in gas wells with small annular space and under other unique well conditions,which will frustrate the operators in the implementation of technical measures in further well development.In recent years,based upon the previous studies on how to improve the cementing quality of gas wells,the latest research also focuses on a special cementing unit of enhancing both the slurry performance and the displacement efficiency of annular drilling fluid.Thus,a drillable downhole hydraulic pulsing generation unit with high capacity displacement and low-frequency & self-excited vibration is developed according to the fluid's self-excited vibration theories,simulation results,and the optimized design.This unit's external diameter is 177.8 mm,its working pressure is at 0.5-1.5 MPa,its working displacement is of 25-30 L/s,and its pressure pulse output frequency is of about 10 Hz;this unit uses round thread casing coupling for connection,and is quite easily drilled through by roller bits or PDC bits.The unit was successfully used for the cementing with φ177.8 mm liner in the Anyue Block of the Sichuan Basin,which proves that the unit is reliable and the cementing quality is highly improved.This technology is initially used in the cementing of intermediate casing of the borehole to be further deepened,which helps expand the scope of application of vibration cementing technology in the cementing quality improvement of oil and gas wells.