PDC切削齿直径对切削力的影响规律研究  

Influence of PDC Cutter Diameter on Cutting Force

作　　者：未九森 邵方源 谭紫阳 刘维 高德利[1] Wei Jiusen;Shao Fangyuan;Tan Ziyang;Liu Wei;Gao Deli(MOE Key Laboratory of Petroleum Engineering,China University of Petroleum(Beijing))

机构地区：[1]中国石油大学(北京)石油工程教育部重点实验室

出　　处：《石油机械》2023年第4期8-15,共8页China Petroleum Machinery

基　　金：国家自然科学基金创新研究群体项目“复杂油气井钻井与完井基础研究”(51821092);国家自然科学基金重点项目“复杂结构‘井工厂'立体设计建设基础研究”(52234002);国家自然科学基金石油化工联合基金项目“页岩和致密油气田高效开发建井基础研究”(U1762214);中国石油大学(北京)科研启动基金项目“高效钻头的研究”(ZX20190065);中石油战略合作科技专项专题“陆相页岩油深部地层钻井提速技术研究”(ZLZX2020-01-07-01)。

摘　　要：针对不同地层岩性特点,需进行个性化PDC钻头设计,其中PDC切削齿的直径是重要的钻头优化设计参数之一。为了探究不同PDC切削齿直径对破岩切削力的影响,通过室内模拟试验方法进行研究。试验所用岩样为石灰岩。单齿破岩试验选取了ø13.44、ø15.88、ø19.05、ø21.95 mm的常规圆柱状PDC切削齿和3个不同的切削深度作为试验变量,使用三轴力传感器记录了切削力数据并收集了岩屑,对比了不同试验条件下单齿破岩过程的机械比能和不同直径切削齿的攻击性;使用水平钻机进行了全尺寸钻头破岩试验,对比了3种不同PDC切削齿直径的钻头在3 mm左右吃入深度下的破岩机械比能。试验结果显示:PDC切削齿的破岩切削力并不随着直径的增大而增大;在相同吃入深度下,ø19.05 mm齿的破岩效果最好;随着吃入深度的增加,切削岩石所需要的力变大。全尺寸钻头破岩试验结果表明,ø19.05 mm齿的全尺寸钻头机械比能最低。分析认为,在破岩过程中,PDC切削齿直径会改变岩石内部产生的应力区域,影响PDC切削齿的破岩效果。选取与岩性匹配的PDC切削齿直径能够取得最优的破岩钻进效果。研究结果可为PDC钻头优化设计提供部分理论指导。PDC bit design needs to be customized depending upon the formation lithology characteristics, and especially the diameter of PDC cutter is an important parameter in bit design optimization.A series of laboratory simulation tests were conducted to explore the influence of PDC cutter diameter on rock-breaking cutting force.The rock samples used in the tests were limestone.In the rock-breaking test of single cutter, the ø13.44, ø15.88, ø19.05 and ø21.95 mm conventional cylindrical PDC cutters were tested at three cutting depths, the triaxial force sensor was used to record the cutting force data, the cuttings were collected, and the mechanical specific energy of single cutter rock-breaking process under different test conditions and the aggressiveness of different diameters of cutters were compared.Moreover, full-scale bit rock-breaking test was performed using the horizontal drilling rig, and the rock-breaking mechanical specific energies of bits with three PDC cutter diameters at about 3 mm penetration depth were compared.The test results show that the rock-breaking cutting force of PDC cutter does not increase with the increase of diameter.At the same penetration depth, the rock-breaking effect of ø19.05 mm cutter is the best.As the penetration depth increases, the force required to cut the rock becomes larger.The rock-breaking test results of full-scale bit show that the mechanical specific energy of ø19.05 mm cutter full-scale bit is the lowest.It is believed that in the process of rock-breaking, the PDC cutter diameter changes the stress area generated inside the rock, thereby affecting the rock-breaking effect of PDC cutter.Use of a PDC cutter diameter matching the lithology can achieve the optimal rock-breaking effect.The research results provide some theoretical guidance for the optimization design of PDC bit.

关 键 词：PDC钻头 破岩效率 切削力 机械比能 单齿破岩 全尺寸钻头破岩 

分 类 号：TE921[石油与天然气工程—石油机械设备]