微心PDC钻头设计及现场试验

Design and Field Application of a Micro-Coring PDC Bit

田京燕 徐玉超

TIAN Jingyan XU Yuchao

中石化胜利石油工程有限公司钻井工艺研究院，山东 东营 257000

Drilling Technology Research Institute, Sinopec Shengli Oilfield Service Corporation, Dongying, Shandong, 257000, China

为了解决普通PDC钻头形成的岩屑细碎、无法满足岩屑录井，而采用牙轮钻头进尺少、机械钻速低又存在掉牙轮风险的问题，设计了微心PDC钻头。介绍了微心PDC钻头整体结构设计和结构参数优化方法, 设计制造了小尺寸微心钻头，进行了室内取心试验和提速试验；结合临盘油田街403井和胜坨油田坨202井实钻地层的岩性特征，分别设计制造了ϕ215.9 mm微心PDC钻头，进行了现场试验。室内试验和现场试验结果均显示：该钻头获取的岩屑较大，大小与牙轮钻头产生的钻屑相当，能满足岩屑录井的要求；而且，钻头进尺和机械钻速与普通PDC钻头相当，与牙轮钻头相比有明显提高。研究结果表明，微心PDC钻头可以代替牙轮钻头在岩屑录井井段使用，并能达到提速提效的目的。

During coring, the cuttings obtained by an ordinary PDC bit are broken into small bits and cannot meet the minimum necessary conditions for logging cuttings.Further, the cone bit has small footage, low ROP and there are high risks of cone breakage.In order to overcome these challenges, a micro-coring PDC bit was designed.This paper describes the overall structural design and also describes the best method for optimizing structural parameters for the micro-coring PDC bit.Aligning with the results of mechanical analysis, a small-size bit was designed and manufactured, and laboratory coring experiments and acceleration experiments were carried out.Using specifications developmed from the formation lithology from Well Jie 403 in Linpan Oilfield and Well Tuo 202 in Shengtuo Oilfield, a ϕ215.9 mm micro-coring PDC bit was designed and manufactured.The bit was then sent to the field where it was put into use in order to verify the design.Both the results of laboratory experiments and the field tests showed that the cuttings obtained by this bit were relatively large and the size was equivalent to that drilled by a cone bit, which could meet the requirements of cuttings logging.In addition, the bit footage and ROP were similar to that of ordinary PDC bit, and the efficiency was significantly improved compared to the cone bit.The results showed that the micro-core PDC bit could replace the cone bit in the interval for logging the cuttings, and could improve the efficiency due to its higher ROP.

国家科技重大专项“致密油藏开发钻井技术优化及集成” 2017ZX05072-003

https://doi.org/10.11911/syztjs.2018134