摘要
川西北部双鱼石构造栖霞组是四川盆地天然气增产上储的重要层系,但该区块以须家河组为代表的难钻地层面临钻头破岩难、磨损快,机械钻速低,单只钻头进尺短的瓶颈问题,严重制约了栖霞组气藏钻井提速和整体勘探开发进程。选取区块须家河组下部(须二、须一段)露头岩样和出井岩屑,开展了岩石可钻性、研磨性和抗钻机理分析实验。结果显示:测试岩样的可钻性级值平均为8.45,须一段岩样均为最高的10级,标准杆件平均研磨量为16.26 mg,整体表现出极强的抗钻性。分析认为:须家河组下部地层孔隙度渗透率极低,石英含量高,胶结强度高,岩石抗压强度和硬度高,不利于钻头冲击/切削破岩和水力辅助破岩,是导致机械钻速极低的主要原因;宏观上的高强度高硬度以及钻屑颗粒在细观与微观尺度上的强研磨性,是导致钻头牙齿冲击破坏和研磨失效的关键因素,也是后续钻头研发和选型的重点攻关方向。
The Qixia Formation of Shuangyushi structure in northwestern Sichuan Basin is an important strata for increasing reserve and production of natural gas in the Sichuan Basin.However,the difficult drilling strata represented by Xujiahe Formation in this block were faced with the bottleneck problems such as difficult rock breaking,fast wear,low rate of penetration(ROP)and short footage of a single bit,which seriously restricts the drilling speed and the overall exploration process of Qixia Formation gas reservoir.The outcrop rock samples and cuttings from the lower Xujiahe Formation(X2 and X1)were selected to carry out the analysis experiments of rock drillability,abrasivity and anti-drilling mechanism.The results show that the average drillability grade of the tested rock sample are 8.45,while all the sample of X1 Formation reach the highest grade 10.In addition,the average grinding amount of the standard bar are 16.26 mg,showing extremely strong drill resistance.Analysis considered that the low porosity and permeability,high quartz content,high cementation strength,compressive strength and hardness in the lower Xujiahe Formation are not conducive to rock breaking with impact and cutting of bit and hydraulic assisted,which is the main reason for the low ROP.Macroscopically high strength and hardness,as well as the strong abrasion of drilling cuttings in micro scales are not only the key factors leading to the impact failure and grinding failure of the bit teeth,but also the key direction of the subsequent research and selection of drill bits.
作者
刘彬
姚建林
杨斌
LIU Bin;YAO Jian-lin;YANG Bin(CCDC Petroleum Drilling and Production Technology Co., Ltd., Guanghan 618300, China)
出处
《科学技术与工程》
北大核心
2022年第18期7846-7852,共7页
Science Technology and Engineering
基金
成都理工大学与中石油川庆钻探公司校企合作项目(CQCDLG-2020-05)。
关键词
双鱼石构造
须家河组
可钻性
研磨性
抗钻机理
Shuangyushi structure
Xujiahe formation
drillability
abrasivity
anti-drilling mechanism
