大井径液压式扩眼器的研制与应用

中国石油化工股份有限公司承建的土耳其TuzGlü天然气地下盐丘储气库,需要将井眼由215.9mm扩至444.5mm,此类扩眼作业在国内外均属首次。在分析扩眼施工技术难点的基础上,利用先进的有限元和三维ProE软件对扩眼器进行了力学分析和优化设计,最终研制出了YK304-444.5液压式扩眼器。其结构组成和工作原理为:由本体、活塞总成、上下限位机构和切削刀翼等组成;依靠钻井液流经活塞上的喷嘴产生一定的压降,推动活塞下行张开3个扩眼刀翼,并由活塞上的支撑装置锁紧。采用新研制的扩眼器顺利地完成了UGS-6等井的扩眼施工作业,未出现工具损坏问题,扩眼后的井眼直径达到设计要求。同时还在实践中不断地完善了盐岩层的大井径扩眼作业技术,并优选出如下作业技术参数:1钻压应控制在30kN以内,以减小扩眼过程中的扭矩;2排量介于45~55L/s,转速介于60~70r/min;3在进行盐层扩眼时要求使用饱和盐水钻井液。

Development and application of a large-diameter hydraulic reamer

In the Turkey TuzGǒlü salt cavern gas storage project undertaken by Sinopec, it is necessary to enlarge the borehole from 215.9 to 444.5 mm. However, this kind of reaming operation has never been carried out either in China or in foreign countries before. In this case, based on the analysis of technical difficulties in reaming operation, with the assistance of ABAQUS and ProE software, a mechanical analysis and an optimal design of the reamer were completed and a YK304-444.5 hydraulic reamer was developed finally. This reamer consists of a tool body, a piston assembly, upper and lower spacing devices, and cutter blades. Once pumping on, drilling mud will flow through the piston nozzle and generate a pressure drop to push the piston moving downward, force the three reamer blades opened, and then drive the support on the piston to lock. With this optimized reamer, the reaming operation in Well UGS-6 and other wells was successfully completed without any tool damage, and the hole diameter after reaming also met the design requirements. The large-diameter reaming technology in salt deposits needs to be optimized gradually in field application: (1) WOB should be controlled within 30 kN in order to decrease the torque in the reaming operation; (2) the flow rate should be 45-55 L/s and the rotation rate be 60-70 r/min; and (3) saturated saltwater drilling fluid should be used in the reaming operation in salt deposits.