摘要
充气控压钻井技术将充气欠平衡钻井和控压钻井技术结合，主要应用于窄密度窗口和对储层保护要求较高的低孔、低渗地层。结合充气钻井工艺特征，考虑注气初期井筒中气体运移规律，建立了环空井筒多相流瞬态模型，并将计算值与实验测量值进行对比，验证了该模型的稳定性和精度。模拟了截面含气率随井深变化规律，以及排量、注气量和井口回压调整时井底压力动态变化规律。结果表明：带压1-2MPa钻进可以大幅改善近井口处两相流流型，有利于安全高效作业；在井筒压力控制对应的工程参数中，调整井口回压的时效性最高，排量其次，注气量最差。研究结果为充气控压钻井中作业参数选取提供了理论依据。
Aerated-managed pressure drilling( AMPD) technology,which combines the aerated underbalanced drilling and managed pressure drilling,is mainly applied in low-porosity and low-permeability reservoirs with narrow density window and higher requirements for reservoir protection. Considering the characteristics of aerated drilling and the gas migration rules at the early stage of gas injection,the annulus and borehole multi-phase flow transient model is established. The calculation result is compared with measured result,verifying the stability and accuracy of the model. The change of sectional gas content with well depth is simulated.The change of bottomhole pressure behavior with the adjustment of flow rate,gas injection volume and wellhead back pressure is also simulated. It is found that the drilling with 1 ~ 2 MPa pressure can greatly improve the two-phase flow regime at the wellhead,which is favorable for safe and efficient operation; in engineering parameters controlled by borehole pressure,highest efficiency is obtained by adjusting wellhead pressure,followed by flow rate and gas injection volume. The research results provide theoretical basis for selection of operational parameters for aerated-managed pressure drilling.
出处
《特种油气藏》
CAS
CSCD
北大核心
2014年第5期138-142,158,共5页
Special Oil & Gas Reservoirs
基金
国家自然科学基金重点项目"控压钻井测控理论及关键问题研究"(51334003)
国家科技重大专项"窄密度窗口安全钻井技术与配套装备"(2011ZX05021-003)
国家重点基础研究发展计划("973"计划)"深井复杂地层钻井压力系统模型与规律"(2010CB226704)
关键词
充气控压钻井
气体运移
瞬态模型
注气量
排量
井口回压
aerated-managed pressure drilling
gas migration
transient model
gas injection volume
flow rate
wellhead back pressure
