水平井钻井水力振荡器安放位置优化与试验

OPTIMIZATION AND FIELD TEST OF HYDRAULIC OSCILLATOR PLACEMENT DURING HORIZONTAL WELL DRILLING

水平井钻井中时常遇到摩阻高、托压、钻速低的问题,而水力振荡器是解决这类问题的有效手段之一,由于常规钻柱摩阻预测无法考虑水力振荡器影响,对水力振荡器的最佳安放位置仍然存在争议.为此,考虑水力振荡器产生轴向振动的影响,基于Dahl动态摩擦模型和常规刚杆模型建立了钻柱动态摩阻计算模型,并以井口实测的大钩载荷验证了该模型的准确性,分析了水平井摩阻分布特征和规律,并优化了水力振荡器的安放位置,最后开展现场验证试验.结果 表明,钻柱动态摩阻计算模型计算得到的大钩载荷与实测数据一致性好、精度高,最大误差13.19%,平均误差仅4.90%;苏里格气田试验区水平井斜井段的最佳安放位置距离钻头60~ 80 m,水平井段的最佳安放位置距离钻头60 ~ 100 m;现场试验结果表明,斜井段械钻速提高了39.01%,水平段机械钻速提高了41.57%,提速效果明显.

High drill string drag,high low-side support pressure in the horizontal section and low ROP are problems often observed during the horizontal well drilling.The hydraulic oscillator is an effective way to solve this kind of problem.Because the conventional drill string drag prediction method hasn’t considered the hydraulic oscillator’s effects,the best placement of hydraulic oscillators is still controversial.Therefore,considering the influence of axial vibration generated by hydraulic oscillators,a dynamic drill string drag model is established based on Dahl dynamic friction model and conventional rigid rod model.The accuracy of this model is verified by the hook load measured at wellhead.The characteristics and rules of horizontal well drag distribution are analyzed,and the placement of hydraulic oscillators is optimized.Finally,field verification tests are carried out.The results show that the dynamic friction model calculated drill string drag is well consistent with the measured data and the precision is high.The maximum error is 13.19%and the average error is only 4.90%.In Sulige Gas Field,the best position in kickoff section is 60~80 m away from the drill bit,the best position in the horizontal section is 60~100 m away from the drill bit.The field test results show that the ROP of the inclined section is increased by 39.01%and the ROP of the horizontal section is increased by 41.57%.The dynamic drag/friction calculation model of drill string and the optimization results of the placement of hydraulic oscillators can provide the theoretical basis and support for the rational application of hydraulic oscillators.