海上小井眼脉冲空化射流发生器射流特性室内试验研究

为了经济地开发海上边际油气资源,将小井眼单通道井井身结构及水力脉冲空化射流提速技术相结合研制出了小尺寸（外径为120mm）水力脉冲空化射流发生器,并采用室内试验研究了其射流特性。分析了其在不同排量下的出口压力脉动频率、入出口压力脉动振幅、工具压耗等参数和自激振荡喷嘴的射流特性。研究表明,出口压力脉动频率与排量呈线性增大关系,入口及出口压力脉动振幅随排量增大而呈增大趋势,工具压耗与排量呈2次增大关系,自激振荡喷嘴能够产生负压和空化效应。

Study on j et characteristics of slim-hole hydraulic pulsed cavitating-j et generator by in-house experiment

The technology of hydraulic pulsed cavitating-j et has demonstrated in conventional wellhole field application that it can improve ROP（Rate of Penetration）significantly.Therefore, for economically developing offshore oil and gas resources in marginal regions,combining slim-hole single-channel well and the ROP improving technology of hydraulic pulsed cavitating-jet,a smallsize（outside diameter：120mm）hydraulic pulsed cavitating-jet generator has been devel-oped.In order to figure out its jet characteristics,we have made a research by laboratory experi-ment on its parameters of pulsed frequency,the inlet/outlet pulsating pressure amplitude,pressure loss and jet characteristic of self-oscillating nozzle.The test results show that the pulsed frequency increases linearly with the increase of the flow rate,the inlet/outlet pulsed pressure amplitude increases with the increase of the flow rate,the pressure loss increases quadratic curve with the increase of the flow rate.When the flow rate is 10L/s,the pulsed frequency is 8Hz,the outlet pulsed pressure amplitude is 1.2MPa and the pressure loss is 1.6MPa.The self-oscillating nozzle can bring about negative pressure and cavitation.A research on the mechanism analysis of ROP improving of hydraulic pulsed cavitating-jet has also been made.Its mechanism contains 2 parts：hydraulic j et can improve the efficiency of cuttings cleaning and cavitating-j et can improve the efficiency of rock breaking.