测井资料在膏盐地层钻井工程中的应用

Application of Log Information to Drilling Engineering of Salt and Gypsum Layers

膏盐层地层最大、最小水平主应力在盐岩含量高的地层中表现为较强的不均衡性,造成钻井施工过程中卡钻、井漏等事件时有发生。结合石膏、盐岩地层的沉积和地质特征,充分发挥钻井测井信息量大和连续测量、纵向分辨率高的优势,从地层岩石矿物分析、岩石力学参数计算、孔隙压力、破裂压力、地层应力评价等方法入手,分析测井资料在膏盐地层确定合理钻井液密度、性能、井身结构设计等方面的应用效果,拓宽测井在石油钻井工程中的应用领域。用于岩石力学参数实验的膏盐层钻井取心非常有限,建议适当增加膏盐层钻井取心。

Drill-pipe frozon and mud loss often appear in drilling operations because the maximum and minimum horizontal main stress is greatly non-isostatic. The drilled well＇s log data are used to evaluate rock constituents, formation stress and formation pressure, etc. , which is very important in designs about drilling fluid density, drill bit, wellbore structure and cementing of the same layers in near wells. And, formation lithology, clay and non-clay mineral composition, drilling fluid density, rock machanics parameters, pore pressure, fracturing pressure may be used to investigate complex downhole environments and determine preventive measures, which is also important in optimizing drilling fluids, mud program, mud property and mud maintenance, etc. At present, there are limited drill cores of the salt and gypsum layers used for rock mechanics parameters experiments, so it is suggested we should properly increase the drill cores of such layers.