钻井液粉末状荧光添加剂的核磁共振特性

磺化沥青等粉末状钻井液荧光添加剂有助于保障钻井安全,却不利于油气显示的发现.为了解决油气勘探与钻井安全之间的这个矛盾,创新采用高分辨率低场核磁共振技术,对14种粉末状荧光添加剂进行了不同混入介质(水和钻井液)、不同混入比例(荧光级别)和不同温度(32℃,90℃和150℃)条件下的核磁共振实验研究.结果表明,这些荧光添加剂可分为两类:一类是没有核磁共振信号;另一类会产生一个水化峰,但加弛豫试剂后水化峰消失.因而,粉末状荧光添加剂对采用核磁共振技术发现钻井液中的含油显示没有影响,从而可彻底解放对该类添加剂的使用限制.

Effects of Powdered Fluorescent Additives on NMR Characteristics of Drilling Fluids

The use of fluorescent additives in drilling fluid is beneficial for drilling safety, but may potentially have adverse effects on oil discovery. In this paper, the effects of addition of powdered fluorescent additives on the NMR characteristics of drilling fluids were investigated with high-resolution NMR spectroscopy. A total of fourteen types of powdered fluorescent additives were added to water and drilling fluid at different dosages and temperature (32 ℃, 90 ℃ and 150 ℃). The NMR spectra of the doped water and drilling fluid were then acquired. The results showed that some of the fluorescent additives showed no NMR signal, while the other showed peaks of hydrated additives. In the later case, the peak disappeared after adding relaxation reagent. It was concluded that commonly used powered fluorescent additives have no effects on the NMR characteristics of drilling fluids, and thus can be used without limitation in NMR surface logging.