摘要:
为了使封隔器既能在大井斜处及井眼轨迹方位角变化较大的地方顺利坐封、保护套管压裂,又能进行水力喷射泵正常排液,基于胶筒接触密封理论,结合刚性部件机械强度校核方法,设计了自封压缩式封隔器。首先对胶筒与套管壁的接触应力进行了理论计算,然后在170 ℃条件下对该封隔器的耐压差性能进行了室内模拟试验,最后在施工现场进行了坐封、压裂、水力喷射泵排液试验。理论计算得出,胶筒的最低坐封压力应大于4.36 MPa;封隔器坐封后,胶筒与套管壁的接触应力随工作压差的增大呈线性增大趋势。室内试验显示,10.00 MPa坐封压力下,胶筒能够承受35.00 MPa反向压差;170 ℃条件下,封隔器能够承受70.00 MPa正向压差和50.00 MPa反向压差。现场试验表明,该封隔器能够在井斜角达72.4°的地方顺利坐封、压裂、排液和解封。研究表明,自封压缩式封隔器可解决常规封隔器难以实现的"既在大井斜处及井眼轨迹方位角变化较大地方顺利坐封、保护套管压裂,又能进行水力喷射泵排液"的问题,且应用效果良好,值得推广应用。
Abstract:
In order to set down smoothly at intervals of a well with high deviation or wide variation of well track azimuth, and to protect casings from failure and optimize hydraulic jet pump drainage, a self-sealing compression packer was designed on the basis of rubber contact sealing theory and mechanical strength verification of the rigid parts. Based on the theoretical calculation of contact stress between the rubber cylinder and the casing wall, a physical experiment was conducted on the packer in terms of its resistance to a pressure differential at 170 ℃. In addition, a series of tests were carried out on site, including packer setting, hydraulic fracturing and hydraulic jet pump drainage. Theoretical calculations indicated that the minimum setting pressure of the rubber cylinder would be higher than 4.36 MPa, and the contact stress between the rubber and the cylinder would increase linearly with the increase of pressure differential after the packer is set down. It is indicated from the physical experiment that the rubber cylinder can withstand reverse pressure difference of 35.00 MPa at the setting pressure of 10.00 MPa and the packer can withstand the positive pressure difference of 70.00 MPa and reverse pressure difference of 50.00 MPa under 170 ℃. Field tests demonstrated that the packer can be set and unset smoothly, and used in hydraulic fracturing and drainage in wells with deviation of 72.4°. Compared with a traditional packer, the self-sealing compression packer can solve the problem of setting down smoothly at the interval with high deviation or wide variation of well track azimuthin order to protect the casing from fracturing and achieve hydraulic jet pump drainage.Field tests showed good application results and worthy of wide application in the fields.
百度学术
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