广安地区快速钻井的钻井液辅助增速技术

SUPPLEMENTARY ROP-INCREASE BY DRILLING FLUID TECHNIQUES IN FAST DRILLING OPERATIONS IN GUANG'AN BLOCK

如何实现钻井液的辅助增速为钻井界所重视,国外主要依靠添加一种叫ROP的防泥包剂到水基钻井液中而实现钻井增速效果,但技术手段较单一。为此,针对四川广安地区的钻井提速问题,结合国内外提速研究成果,优选出一套适合于该地区的钻井液辅助增速技术,并应用于广安地区所钻的9口井中,取得了较理想的钻井提速效果,形成了一套较完善的钻井液辅助增速技术。其核心技术是:①使用"三强"高效防塌钻井液,实现较低密度的钻井液钻井,尽量减少井下复杂与事故;②采用多种表面活性剂组合,防止钻头泥包,使钻头高效破岩;③使用结构聚合物,优化高电解质钻井液的动塑比,充分净化井眼,减小压持效应。试验表明,该批井平均机械钻速提高31%,单井平均钻井周期缩短48%。

How to further realize the supplementary ROP-increasing effects of drilling fluid is regarded as an essential issue in drilling industry.Except that an anti-balling additive is often added into the WBM fluid to increase ROP in some countries,not many effective measures can do any help.Based on the related global studies,this case of study refined a set of drilling fluid techniques,optimized to increase ROP complementarily in Guang'an block of the Sichuan Basin.Applications have been tried in 9 wells drilled in Guang'an with ideal results obtained.The core techniques included ①to adopt '3 reinforcement' anti-caving drilling fluid to conduct low-density fluid drilling,which can help to reduce downhole drilling problems,②to adopt a combination of surfactants to prevent bit balling,which will increase a bit's cutting efficiency,and ③to adopt structural polymers to optimize the gel strength/plastic viscosity ratio of high-electrolyte drilling fluid,which can help to clean the well sufficiently and reduce the chip-hold-down effects.Field tests demonstrated that the ROP was increased by 31% in the wells after using the techniques,while the average drilling cycle of individual wells was shortened by 48%.