膏盐岩地层地质特征与录井技术

Geological features and mud logging technology for gypsum and salt rock formation

石油勘探实践和研究结果表明,许多油气藏的形成都与膏盐岩地层有关,也常与膏盐岩地层伴生,成功钻穿膏盐岩地层是钻井难题之一,录井技术成为钻进安全监测、膏盐岩地层准确预报的重要手段。针对上述情况,介绍了膏盐岩地层的主要类型、沉积模式以及与油气的关系,归纳总结了膏盐岩地层的录井技术经验,包括：在随钻录井过程中熟悉地质设计与邻井资料；在没有预测钻遇膏盐岩地层的情况下,通过钻井液中Cl^-的变化判定是否钻遇膏盐岩地层；预计钻遇膏盐岩地层时,使用饱和盐水钻井液；钻遇膏盐岩地层后观察盐岩是否以岩屑形式返出；同时,把握膏盐岩地层的岩性、岩性组合、层位、顶底界和厚度是非常重要的。通过S1井实例分析,论述了在膏盐岩地层中钻进时,防卡、防漏是录井人员监测和预报的重点。

Oil exploration practice and researched results indicate that most of hydrocarbon reservoir forming related to gyp- sum and salt rock formation,and the hydrocarbon is also associated with it,so,successfully drilling through gypsum and salt rock formation has been become one of drilling dif- ficult problems.In accordance with the above circumstance, the paper introduced the main types,sedimentation model of gypsum and salt rock formation,and the relations be- tween it and oil and gas,summed up mud logging technolo- gy experience for gypsum and salt rock formation,which included,knowing geologic design and offset well data,de- termining whether drilling gypsum and salt rock formation or not with observing Cl^-variation in drilling fluid under the condition of not predicating to drill in gypsum and salt rock formation,using saturated salt-water drilling fluid when gypsum and salt rock formation was predicated to be drilled,after drilling gypsum and salt rock formation,ob- serving salt rock returning out whether in cuttings or not, and simultaneously,it is very important to grasp gypsum and salt rock formation's lithology,lithological association, horizons,top and bottom boundaries and thickness.By tak- ing well S1 as an example for analysis,the paper expounded that anti-drill sticking and leaking were the key points for mud logging personnel monitoring and forecasting during drilling within gypsum and salt rock formation.