不同地层的漏失压力分析

Analysis of Leakage Pressure in Different Formation

在钻进压力衰竭地层、破碎或弱胶结地层、裂缝发育地层及多套压力层系等时,井漏诱发的井壁失稳、坍塌、井喷等问题经常发生。本文通过分析地层岩性,确定合适的地层压力计算模型;然后,根据漏失通道,漏速大小分析其漏失类型,结合现场实地数据,得到相应的漏失压力模型。现场应用表明,针对不用地层所选的合理漏失压力预测模型,计算结果与现场符合,对于钻井液安全密度窗口的确定和安全钻进具有重要现场指导意义。

During drilling of pressure failure formation, broken or weak bond formation, fracture development formation and multiple-pressure formation, the well leakage can induce wellbore instability, collapse, blowout and other issues. In this paper, the formation lithology was analyzed, and the appropriate formation pressure calculation model was determined; then, according to the leakage path and leakage rate, the type of the leakage was analyzed. Combined with field data, the corresponding leakage pressure model was obtained. The field application shows that the calculation results are in accordance with the field data.