柴达木盆地昆特依构造超深井钻井难点及对策——以昆1-1井为例

Drilling difficulties in ultra-deep wells and countermeasures:An example from Kun 1-1 well,Kunteyi structure,Qaidam Basin

为了破解柴达木盆地昆特依构造超高温钻井过程中面临的一系列技术难题,以该构造昆1-1井为研究对象,在综合分析其钻井难点的基础上,开展了超深井配套钻井技术研究。通过对抗210℃聚胺有机盐钻井液配方优化、个性化钻头优选、提速工具优选以及超高温防漏堵漏配方的优化,形成了一套针对昆特依基岩地层的超高温钻井技术。研究结果表明:(1)超高温钻井液老化72 h后,高温高压滤失量保持在10 mL以内,流变性能优良;(2)筛选的阿特拉钻头及扭力冲击器组合,提速效果明显,较之于邻井昆2井四开、五开机械钻速提高了10%以上;(3)现场应用雷特抗高温堵漏材料,地层承压能力有效提高,最高承压能力提高到了当量密度2.07 g/cm^(3),顺利完成了柴达木盆地第一超深井的钻探任务。结论认为:(1)针对昆1-1井优选的聚胺有机盐钻井液体系,有效解决了钻井液超高温减稠和悬浮携带稳定性之间的矛盾,超高温高压滤失量得到了有效控制;(2)针对昆1-1井优选的钻头及工具组合、抗超高温防漏堵漏配方,有效解决了现场技术难题,为柴达木盆地超深井钻探提供了有利的技术保障。

In order to develop certain drilling technologies with ultra-high temperature suitable for Kunteyi structure in Qaidam Basin,the ultra-deep Kun 1-1 well was taken as an objective to comprehensively analyze its drilling difficulties.Moreover,some support drilling technologies were studied.A series of drilling technologies with ultra-high temperature for matrix strata in Kunteyi structure were also developed by optimizing the 210℃drilling-fluid composition of polyamine organic salt,selecting customized bit and ROP(rate of penetration)improvement tool,and optimizing and screening ultrahigh temperature lost-circulation prevention and control formula.Results show that(1)after the ultra-high temperature drilling fluid is aged for 72 h,its high-temperature and high-pressure filtration is still less than 10 mL,and its rheological property is good;(2)the selected Atela bit and torque impactor combination has a remarkable effect on ROP improvement.The ROP in the fourth and fifth sections of Kun 1-1 well is 10%higher than that in its neighboring Kun 2 well;and(3)when the Neotoy high-temperature lost-circulation material is applied to field,the bearing capacity of formation pressure may be improved effectively and the maximum capacity can also be increased to the equivalent density of 2.07 g/cm3.Thus,drilling the first ultra-deep well in Qaidam Basin is smooth.These results may provide powerful technical support for drilling subsequent ultra-high temperature wells in this basin.