Abstract: In the heterogeneously distributed area of thin oil and gas pay zones with a varying dip angle, use of gamma LWD instrument for measurements is unable to accurately judge the upper and lower positions of the target layer when the drilling bit reaches the interface between two layers, easily leading to wrong decisions and affecting effective drilling rate of the target layer. The measurement functions of azimuth gamma LWD instrument can be performed through offset installation of gamma probe, quick identification of sector barrier and sector position, and data processing technology and method. This azimuth gamma LWD instrument can make real-time measurement in the logging-while-drilling process and separately display the gamma values of the upper and lower sides of the borehole as well as the average natural gamma value of the peripheral rock off the borehole. When used on the site, it can accurately determine changes in the level series and timely and precisely help the on-the-site geologists and directional engineers with their service work, effectively improving the drilling rate of reservoirs.

摘要： 在油气产层薄、倾角变化大、分布不均匀的地区, 使用常规随钻伽马仪器测量, 当实钻井眼钻头位置到 达层位交接界面时, 不能准确判断预钻层位的上下位置, 易导致决策失误, 影响目的层位的有效钻遇率。通过研究伽 马探测器的偏置安装、扇区屏蔽、扇区位置快速识别及其数据处理等技术和方法, 实现了方向伽马的随钻测量功能。 该方向伽马随钻测井仪能够在随钻过程中实时测量并分别显示井眼高低边的伽马值和井眼围岩的平均自然伽马值, 现 场应用能准确判断层位变化, 及时准确地指导现场地质师及定向工程师的施工工作, 有效提高了产层的钻遇率。

关键词: 方向伽马, 随钻测井, 钻遇率