水力空化储层改造物模实验装置研制与实验探索

Model Experimental System Development and Experimental Exploration of Hydraulic Cavitation Reservoir Stimulation

水力空化储层改造技术是近年提出的一种针对近井壁区域储层进行精细化改造的储层改造技术,具有所需设备少、工艺简单、清洁环保、作业成本低等特点,并能有效改善储层的非均质性。该技术已在国内部分油田进行了初步应用,取得了良好的应用效果,为进一步探究新型水力空化储层改造技术的工作机理与规律,基于空化原理及现场应用情况自主研制了一套水力空化储层改造物模实验装置,并开展了现场实验研究。实验结果表明,空化效应所产生的空泡溃灭区主要集中在以空化器出口为起点,距离为15~25倍空化器出口直径的区域,将改造点设置在此处,能够达到较好的改造效果;同时由于在此处形成局部高压,促使空化器出口区域产生"负压效应",有利于抽吸近井筒区域的污染物,达到解堵的作用;当输入泵力达到17 MPa时空化效应会产生脉冲振动,该振动的强度及传递距离随输入泵压升高而增加,通过对振动强度的衰减率进行分析,水力空化储层改造最远可对距井壁2~3 m的储层产生改造作用。该实验结果为水力空化储层改造技术的施工参数优化提供技术支撑。

Hydraulic cavitation reservoir stimulation technology is a kind of reservoir stimulation technology proposed in recent years for fine stimulation of reservoirs near wellbore area.It has the characteristics of less equipment, simple process, clean and environmental friendly, low operation cost, and can effectively improve the heterogeneity of reservoirs.This technology has been preliminarily applied in some domestic oil fields, and has achieved good application results.In order to further research the working mechanism and law of the new hydraulic cavitation reservoir stimulation technology, a set of hydraulic cavitation reservoir sitimulation model experimental equipment was independently developed based on the cavitation principle and field application, and field experimental research was carried out.The experimental results show that the cavitation collapse zone generated by the cavitation effect is mainly concentrated in the area with the outlet of the cavitation as the starting point and the distance is 15~25 times the diameter of the outlet of the cavitation.If the reconstruction point is set here, a better stimulation effect can be achieved.At the same time, due to the local high pressure formed here, the “negative pressure effect” is generated in the outlet area of the cavitation device, which is conducive to the suction of pollutants in the near wellbore area and the blocking removal.When the input pump pressure reaches 17 MPa, the cavitation effect will produce pulse vibration, and the intensity and transmission distance of the vibration will increase with the increase of the input pump pressure.By analyzing the attenuation rate of the vibration intensity, the hydraulic cavitation reservoir stimulation can transform the reservoir 2~3 m away from the wellbore.The experimental results provide technical support for the optimization of construction parameters of hydraulic cavitation reservoir stimulation technology.