双级反循环连续冲砂工艺技术研究

Research on the two-stage reverse circulation continuous sand washing technology

针对漏失严重的油井积砂问题,研制了双级反循环低压漏失井连续冲砂装置。该装置与负压冲砂工艺配套,利用双级管柱形成内循环通道,由滑动换向装置实现进出口液体转换,从而实现连续冲砂作业。在室内对该装置所有进出口进行加压试验,最高压力30 MPa,无渗漏,在500 kN拉力下无损伤和破坏,各项指标达到设计要求。在高3-85-14等20口井的现场应用表明,该装置可将井内砂子成功地排至地面,保证了作业施工的顺利进行。

In light of the oil-well sand with a serious leakage, the two-stage reverse circulation sand washing device for low-pressure leakage wells was developed. The device was associated with the negative pressure sand washing technology and it adopted the two-stage pipestring to form the internal circulation channel, with the sliding-reversing device to achieve the conversion of entry and exit liquids and to achieve continuous sand washing operation. A pressurized experiment of all the device’s entrances and exits in the laboratory showed that the maximum pressure was 30 MPa, there was no leakage, there were no trauma and damage under the tension of 500 kN and all indexes reached the design requirement. The field application in 20 wells indicated that the device could successfully discharge the down-hole sand to the ground.