川东北空气泡沫钻井液技术及现场调控措施

Air-Foam Drilling Fluid Technology and the Optimization Measures for Field Application in Northeast Sichuan.

根据川东北地层特点,室内研究了适合该地层的泡沫钻井液配方,该配方具有半衰期长、抑制性强、性能稳定等优点,但在现场使用过程中,发现泡沫有段塞、泥岩水化严重等问题,对处理剂加量和加料频率对泡沫钻井液的影响进行了研究,优化了泡沫体系整体性能,页岩的水化膨胀和分散抑制能力明显提高,泡沫质量明显改善,半衰期明显提高,携岩能力显著增强,在泥岩段钻进时的机械钻速提高了31.8%,整个井段钻进过程中无任何复杂事故。同时还给出了快速判断泡沫性能优劣的依据,为川东北地区后续空气泡沫钻井提供了一定的指导。

Air-foam drilling fluid formula was investigated in laboratory suitable for formation in Northeast Sichuan with the properties of long foam half time,strong inhibition and good stabilty.Meanwhile problems encountered in field application were slug flow and severe shale hydration,etc.Pilot tests were carried out on chemical dosage and feeding time interval and optimization measures for drilling fluid performance were run on the basis of test results.The optimized formula has such properties as strong inhibition of shale hydration and swelling,good foam quality,longer half-time and fine cuttings carrying capacity.ROP had increased by 31.8%in shale formation with no accidents occurred in drilling.Reference on judging the foam performance has been proposed,which would provide guidance for other air-foam drilling in Northeast Sichuan.