【摘要】 针对塔里木盆地顺北一区三叠系柯吐尔组坍塌掉块、井径扩大的问题,通过开展微观结构分析,以及进一步实验评价不稳定地层阳离子交换量、岩屑膨胀率和分散性等理化性能,详细研究了复杂地层的坍塌机理。结果表明,三叠系柯吐尔组属于微裂隙发育的中硬到硬脆性泥岩地层,具有"易水化、强分散"的性质。在16 h热滚、90℃条件下,岩屑回收率仅为7.22%。通过聚合物改性,优选了胺基页岩抑制剂HPA和三元共聚物RHTP-2,形成了高性能水基钻井液体系,该体系在顺北1-9井二开4 802 m的超长裸眼段地层成功应用,柯吐尔组平均井径扩大率为9.6%,井径规则,大大节约了钻井时间,表现出优良的抑制防塌性能,解决了顺北区块上部复杂泥岩钻井技术难题,具有广阔的推广应用前景。更多还原

【Abstract】 In order to clarify the mudstone clasping and hole enlargement of Triassic Kotuer Formation in Tarim Basin, the paper studies the microstructure of all rock minerals and clay minerals in the unstable strata. The further analysis of physical and chemical properties suggests that the Kotuer Formation belongs to the medium hard to hard brittle mudstone strata with micro-fractures developed. The main geological characteristic is "easy hydration and strong dispersion". The experiment shows that the average recovery rate is only 7.22% after 16 hours and 90℃. This research indicates that the key agents,shale inhibitor HPA and terpolymer RHTP-2 are developed by polymer modification to form a high performance water based drilling fluid system. This system was successfully applied to the open hole of second spud in the Well Shunbei 1-9. The average diameter expansion rate of Kotuer Formation is 9.6%, which is much better than others in this area. The wellbore is effectively protected from sloughing with small enlargement. Field application shows that the technology has broad application prospects.更多还原