鄂尔多斯盆地北部致密气藏储层保护钻井技术

Drilling technology for reservoir protection in tight gas reservoirs in the northern Ordos Basin

摘要:

鄂尔多斯盆地北部致密气藏储层孔喉微细、裂缝发育且敏感性强，钻井过程中的固相侵入与液相圈闭损害严重，制约了效益开发。为解决储层保护与井壁稳定的矛盾，本文通过深入分析储层损害机理，针对性地研发了自降解暂堵剂与防水锁剂。基于此，创新性地构建了一套集“物理颗粒自降解暂堵、界面修饰防液锁、多元协同稳井壁”于一体的低损害储层保护钻井液体系，并配套了水平井钻井提速技术。现场应用表明，该技术体系有效降低了钻井液侵入深度与储层损害程度，显著提高了单井产量，部分井实现自然建产，为鄂尔多斯盆地乃至同类致密气藏的低成本、高效益开发提供了有力的工程技术保障。

Abstract:

In the tight gas reservoirs of the northern Ordos Basin， the presence of fine pore throats， developed fractures， and strong sensitivity leads to severe formation damage caused by solid invasion and liquid phase trapping during drilling， which restricts efficient development. To resolve the conflict between reservoir protection and wellbore stability， this study conducts an in-depth analysis of the formation damage mechanisms and， consequently， develops targeted self-degradable temporary plugging agents and liquid-lock prevention agents. Based on this research， a novel low-damage reservoir protection drilling fluid system is innovatively constructed， integrating "physical particle self-degradable temporary plugging"， "interface modification for liquid-lock prevention"， and "multi-synergistic wellbore stabilization". This system is complemented by a horizontal well drilling acceleration technology. Field applications demonstrate that this technological system effectively reduces the depth of drilling fluid invasion and the extent of formation damage. It significantly improves the single-well production， with some wells achieving natural production without fraturing operation. This research provides robust engineering and technical support for the low-cost and efficient development of tight gas reservoirs in the Ordos Basin and similar tight gas reservoirs.