Optimum Design And Experimental Study Of Descaling Device With Rotating Water Jet For Tubing

Tubing scaling is a common problem in the middle to late stages of oil and gas production.Tubing scaling will reduce the flow area of the tubing,reduce the efficiency of oil and gas transportation,and even lead to the scrapping of oil and gas wells,seriously affecting the safety of oil and gas production.The traditional mechanical scraping and chemically dissolved descaling methods are easy to damage the pipeline and cause pollution,and the high-pressure water jet descaling technology has the characteristics of indirect contact impact removal of scales,and the scale body is eroded without hard contact with the pipe wall surface.The spray nozzle has a smaller configuration,which is more suitable for complex scaling environment,and can safely and effectively remove scale bodies with complex shapes and compositions.Therefore,the research and development and parameter optimization design of high-pressure water jet descaling device for tubing have important engineering significance in the field of tubing descaling.This paper analyzes the key performance parameters of high-pressure water jet descaling based on the mechanism of jet descaling,combined with the structure of the tubing and the scale body.A rotary water jet descaling device that can be used for descaling of the tubing is preliminarily designed.The mechanical numerical simulation method optimizes the parameters of the key components-the nozzle and the descaling device as a whole,and finally tests the descaling effect of the rotary water jet descaling device for the tubing through the indoor descaling experiment.The main results achieved are as follows:(1)Proposed the overall design scheme of the pressure-driven rotary water jet descaling device with a combination of multi-angle nozzles and double bearings.The key parameters such as the equivalent diameter of the descaling nozzle were theoretically calculated,the nozzle arrangement was preliminarily determined,and the number and number of nozzles were established.The matching relationship between the number of nozzles and the diameter of a single nozzle was established.(2)Optimized the key components of the descaling device-the structure of the nozzle and its structural parameters.The structural parameters that affect the descaling performance of the nozzle,such as the length of the straight line section,the convergence angle and the total length of the nozzle are theoretically determined.Through the orthogonal simulation experiment,the optimal combination of the length of the straight-line section,the convergence angle and the length of the convergence section of the nozzle for the descaling of the oil pipe with the outlet diameters of 1.5mm,2.0 mm,2.5 mm,and 3.0 mm were optimized.(3)Optimized the internal structure of the descaling nozzle of the rotary water jet descaling device for tubing.The nozzle installation angle when the number of nozzles installed is 3,4,6 is optimized.A set of rotary water jet for tubing is developed according to the design structure and optimization parameters Descaling device.(4)The descaling performance of the descaling device under the working pressure of 5 ? 25 MPa was tested through the indoor simulated descaling experiment.The results show that the device can achieve rotary descaling when the working pressure reaches10 MPa,and the descaling thickness increases with the increase of the jet pressure;When the working pressure is 20 MPa,the thickness of the residual scale is less than1 mm,which meets the requirements of descaling;the particle size of some broken scales is conducive to the reverse flow of the jet.