摘要
气体钻井是川东北陆相地层主要提速措施之一,在气体钻井钻达设计井深或井下异常时需进行气液转换。转换后经常因井壁失稳带来长时间携砂或划眼等问题,大大降低了气体钻井提速带来的综合效益。针对气体钻井后井壁易吸水坍塌的特点,提出采用油基前置液对井壁进行润湿反转预处理的防塌措施,并制定出旋转喷淋转换工艺。该工艺采用原钻具组合直接转浆及划眼,提高了气液转换效率,总转换时间由原来的5~22 d缩短至4 d以内。
Gas drilling is the main tool for continental strata in northeastern Sichuan Basin to increase the drilling rate. However, it's necessary to implement a gas and liquid conversion while abnormal situations occur at designed well depth. And after the conversion, borehole instability may bring about some problems of sand carrying and reaming, further to affect economic benefits. So, in order to solve a problem of easy borehole collapse after gas drilling,an anti-collapse measure to implement the pretreatment of wettability alteration using oil-based prepad fluid is presented, and a technology of rotated spray conversion is developed. By adopting the original drilling assembly, this technology can realize the reaming and increase the efficiency of gas and liquid conversion. As a result, the total conversion time, which the original one was between 5d to 22 d, is cut to 4d.
出处
《天然气技术与经济》
2017年第2期39-42,共4页
Natural Gas Technology and Economy
关键词
气体钻井
气液转换
井壁失稳
润湿反转
gas drilling
gas and liquid conversion
borehole instability
wettability alteration
