冻结孔泥浆置换中缓凝水泥浆及混合浆的性能劣化规律  

Performance deterioration law of retarded cement slurry and its mixed slurry in freezing borehole mud replacement

作　　者：李强 王衍森[2] 王春林 徐圣集 樊志强[2] LI Qiang;WANG Yansen;WANG Chunlin;XU Shengji;FAN Zhiqiang(Shaanxi Yanchang Petroleum and Mining Co.,Ltd.,Xi’an 710075,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,China;Shaanxi Yanchang Petroleum Balasu Coal Industry Co.,Ltd.,Yulin 719000,China)

机构地区：[1]陕西延长石油矿业有限责任公司,陕西西安710075 [2]中国矿业大学深部岩土力学与地下工程国家重点试验室,江苏徐州221116 [3]陕西延长石油巴拉素煤业有限公司,陕西榆林719000

出　　处：《煤田地质与勘探》2021年第5期182-189,共8页Coal Geology & Exploration

基　　金：国家自然科学基金面上项目(52074264)。

摘　　要：冻结孔泥浆置换已成为岩层冻结法凿井的必需环节,但冻结管下放易遭遇浆液黏滞阻力过大,甚至被"抱死"导致钻孔报废。为深入掌握深孔环境中水泥浆及其与泥浆混合浆的性能劣化规律,以表观黏度作为衡量指标,考虑养护时间、温度、失水状态及混合浆的体积比等因素,分别开展缓凝水泥浆、混合浆的室内试验研究。结果表明:养护时间20 h内,水泥浆和混合浆的黏度均随养护时间延长而增长,但混合浆黏度值及增长速率远超过水泥浆;二者黏度与温度之间呈非线性变化关系;失水状态加速浆液的黏度增长,尤其是对混合浆的黏度影响更大;混合浆的黏度与体积比之间呈现为非线性关系;与缓凝水泥浆相比,混合浆的黏度剧增等性能劣化现象,受养护时间、温度及失水状态的影响都更为显著。分析认为,水泥与泥浆的混合浆液的黏度骤升、流动性大幅下降甚至丧失,是冻结管下沉阻力过大甚至被"抱死"的关键原因;因此,控制浆液混合段高度,抑制混合浆的黏度增长,是保证冻结管安全顺利下沉的关键。The mud replacement of freezing hole has become a necessary part of freezing shaft sinking in rock strata,but in the lowering process, the freezing pipe is prone to excessive slurry viscosity resistance, and even be locked,leading to borehole failure. In order to deeply understand the performance deterioration law of cement slurry and its mixture in deep hole environment, the laboratory tests of retarded cement slurry and mixed slurry are carried out respectively, taking the apparent viscosity as the measurement index and considering the factors such as curing time,temperature, water loss state and volume ratio of mixed slurry. The results show that the viscosity of the cement slurry and mixed slurry increases with the extension of curing time, but the viscosity value and growth rate of the mixed slurry are much higher than those of the cement slurry within 20 h of curing time. The viscosity of the both has a nonlinear relationship with temperature. And the viscosity growth of slurry is accelerated by water loss state,especially the viscosity of the mixed slurry. The viscosity and volume ratio of the mixed slurry show a non-linear relationship. Compared with the retarded cement slurry, the viscosity of the mixed slurry increases sharply which is more affected by curing time, temperature and water loss state. The analysis shows that the sudden increase of viscosity and the sharp decrease or even loss of the fluidity of the mixed slurry are the key reasons for the excessive sinking resistance and even the locked freezing pipe. Therefore, controlling the height of the slurry mixing section and inhibiting the viscosity growth of the mixed slurry are the key to ensure the safe and smooth sinking of the freezing pipe.

关 键 词：冻结孔 泥浆置换 缓凝水泥浆 混合浆 表观黏度 性能劣化 

分 类 号：TD265.4[矿业工程—矿井建设]