舟山海域淡水资源调查岩心钻探技术

Technology of Core Drilling for Investigation of Freshwater Resources in Zhoushan Sea

摘要:

舟山海域淡水资源调查项目DZS1孔，水深15 m、钻孔深度达202.1 m，在以粘土层和砂层为主的第四系覆盖层全孔取心、在风化基岩层取心2 m。在第四系覆盖层不下套管直接利用φ127 mm钻具进行绳索锤击取心钻探，基岩采用φ127 mm钻具作为套管、φ50 mm钻具单动双管回转取心钻探。介绍了该孔的主要施工工艺与质量控制方法，包括勘探船抛锚定位、潮汛对钻杆的影响、钻探取心过程控制、用取心钻头不取心扫孔技术、更换钻头技术、泥浆工艺等。

Abstract:

For DZS1 well of freshwater resources investigation project in Zhoushan sea, the drilling was started at water depth of 15 meters. The full hole coring depth reaches 202.1 meters by drilling in overburden layer mainly with clay and sand layers and 2 meters of weathered bedrock. In the quaternary, 127mm drill pipe was directly used for wire-line hammer collision coring drilling without casing; in bedrock, 50mm drill pipe was used for swivel type double tube coring drilling with 127mm drill pipe as casing. The paper introduces the main construction processes and quality control methods, including anchor of drill ship, consideration of tide impact on drilling pipe，control of drilling procedure, hole cleaning, drill bit replacement，mud technology and so on.