裸眼完井下的大位移井裂缝起裂研究

随着大位移井数量的增加,大位移井压裂逐渐成为油气藏的一种重要增产技术手段。大位移井水力压裂裂缝起裂与直井、普通定向井有显著差别,其起裂模式不仅与井眼轨迹(井斜角、方位角等) 有关,而且还与地应力方位密切相关。以往的斜井裂缝起裂模式已经不能满足大位移井压裂设计的需要。考虑作业条件、压裂液渗滤效应和孔隙压力的影响,建立了大位移井井筒周围应力场分布模型,提出了裂缝起裂压力和起裂方位预测模型,并分析了不同构造应力范围对大位移井压裂裂缝起裂的影响。计算结果表明,建立的模型完全适用于大位移井压裂设计的需要。

STUDY OF FRACTURE INITIATION OF THE EXTENDED REACHWELLS WITHOPENHOLE COMPLETION

The Hydraulic Fractured Extended Reach Wells ( ERW)has been became an important technical means of reservoir stimulation with increasing amount of the ERW. The fracture initiation of fractured ERW differ from those of the vertical and the conventional directional wells , the initiation mode is not onlyrelative to the well trajectory (deviation and azimuth angle) but also the in - situ stress azimuth. The prior initiation mode of the deviated wells has not been satisfied with the demand of fractured ERW , based on influencing factors of the treatment condition and the filtration effect of fracturing fluid and the pore pressure , this paper established the model of the stress field distribution around the ERW wellbore and presented the predicting model of fracture initiation pressure and azimuth , and analyzed the fracture initiating influence under the condition of different inOsitu stress configuration. The calculated results show that the model presented in this paper can be able to apply to the hydraulic fractured ERW.