“NEW-DRILL”提速新工具在元坝气田的应用

元坝气田陆相深部的自流井组和须家河组地层岩性致密,非均质性强,砾岩含量高（最高可达50%）,地层研磨性强（可钻性为8 级以上）,且钻井液密度高（最高可达2.4 g/cm3）,压持效应大,导致牙轮钻头磨损速度快,单只钻头进尺少,是制约元坝钻井提速的关键层段。为了解决这一关键层段钻井提速问题,针对元坝陆相深部高压致密研磨性地层的钻井难点,从破岩工具入手,通过对破岩机理的进一步研究分析,提出了要应用为钻头提供持续的扭矩、恒定转速和钻压的动力工具,以增加钻头的破岩能力,减少钻柱的震荡,减少切削时滑脱和钻压波动,同时配合高效的PDC 钻头或孕镶金刚石钻头,从而提高钻井效率的思路。为此,元坝气田开展了“NEW-DRILL”提速新工具的现场应用,获得了成功,取得了明显的效果。使元坝气田三开平均机械钻速由0.76 m/h 提高到2.06 m/h;周期由150~170 d 缩短到90~110 d。缩短率为35%,有效地解决了元坝气田钻井提速的技术瓶颈问题。现场应用表明,“NEW-DRILL”提速新工具能够有效提高陆相地层的机械钻速,具有进一步推广应用前景。

Application of new accelerating tool NEW-DRILL in Yuanba Gas Field

The Ziliujing Formation and Xujiahe Formation of Yuanba Gas Field is characterized by tight formation lithology, strong heterogeneity, high content of conglomerate (max. up to 50%), high formation abrasiveness, low drillability (over Level 8), and high drilling fluid density (max. up to 2.4 g/cm3), great chip-holddown effect, low rock breaking efficiency, fast roller bit wear, small footage of single bit and low comprehensive benefit. They are the main intervals which hinder acceleration of drilling rate in Yuanba Gas Field. In order to address this problem, and in line with the drilling difficulties in high pressure tight abrasive formations in the deep continent facies of Yuanba, research and analysis was conducted on rock breaking mechanism starting from rock breaking tools, and a new power tool was proposed which aims to provide continuous torque, constant RPM and bit pressure for the bit, so as to increase the rock breaking capacity of the bit, reduce drill string vibration, decrease slippage and bit pressure fluctuation during cutting, meanwhile, with high-efficiency PDC bit or impregnated diamond bit, to increase drilling efficiency. For this purpose, the new accelerating tool NEW-DRILL was field tested in Yuanba Gas Field and was successful and effective, which increased the average penetration rate of 3rd opening in Yuanba Gas Field from 0.76 m/h to 2.06 m/h and shortened the drilling cycle from 150-170 d to 90-110 d. The shortening rate was 35%, which effectively solved the technical bottleneck of accelerating drilling rate in Yuanba Gas Field. Field application shows that NEW-DRILL can effectively increase the penetration rate in continental formations and can be further promoted and used.