MRC近钻头地质导向系统总体设计与应用

地质导向钻井技术已成为复杂结构井地层评价的重要手段。但常规地质导向系统测量参数测点平均测量零长大于20 m,离正钻地层较远,测量信息相对滞后,对薄油层开发尤其不利,并且常规自然伽马测量不具有测量方位信息能力,不能及时判断钻具在油层中发生的变化。胜利钻井院研制的MRC近钻头地质导向系统采用电磁波电阻率、方位伽马和井斜一体化设计技术,实现近钻头地质参数与工程参数集成测量,实现了近钻头测量,大大缩短了测量零长(测量零长小于10 m),能够实时监测地层特征信息、辨别地层变化,测量的参数具有方位特性,能够确定储集层边界的位置,利于及时调整井眼轨迹,降低打穿油层的风险,提高储层钻遇率。现场应用证明,该系统测量数据准确、工作稳定可靠,应用单井都获得了较高的储层钻遇率。通过与常规地质导向系统应用效果对比,该系统更能实现对地层特性的判断和钻头在储层内穿行精确控制,平均单井储层钻遇率提高10%以上,可为薄油层的开发提供有力的技术支撑。

Overall design and application of MRC near-bit geosteering system

Geosteering drilling technology has become an important method for stratum assessment of wells in complex structure. However, survey points of measuring parameters of conventional geosteering system feature average measuring zero length above 20 m, relatively far away from drilling stratum, thus causing relative lag of survey information, which is in particular adverse for thin reservoir development, and conventional natural gamma surveying does not have the capacity of measuring azimuth information, and cannot timely judge change of drilling tools in oil reservoir. The electromagnetic wave resistivity, azimuth gamma and well deflection integrated design technology, which is developed by Shengli Drilling Technology Research Institute and is adopted by MRC near-bid geosteering system, realizes integrated measurement of near-bit geological parameters and engineering parameters, and realizes near-bit (measuring zero length less than 10 m) measurement, greatly shortens measuring zero length It also realizes real-time monitoring of stratum feature information as well as identification of stratum change. The measurement parameters has azimuth features to enable determination of location of boundary of reservoir stratum, facilitate timely adjustment of well track, lower the risk of reservoir penetration and improve catching rate. It has been proved from field application that the system features accurate measured data, stable and reliable operation, and achieves high reservoir catching rate in single-well application. In comparison with the application effects of conventional geosteering system, the system better realizes judgment of stratum features and accurate control of drill track inside reservoirs, and improves average reservoir catching rate for single well by above 10%, and can provide powerful technical support for development of thin oil reservoir.