Mechanics experiment system and method for perforated string in underground perforating blasting of oil-gas well

A mechanics experiment system for a perforated string in underground perforating blasting of an oil-gas well, comprising:

• an experiment water pool, a perforated string arranged in the experiment water pool, a signal amplifier, an A/D converter and a computer, wherein the signal amplifier, the A/D converter and the computer are arranged outside the experiment water pool and are sequentially electrically connected;
• the perforated string comprises an oil pipe, a packing tube, a sleeve, a first acceleration testing short joint, a damper, a second acceleration testing short joint and a perforating gun sequentially connected from top to bottom;
• a lower end of the sleeve is provided with an outer thread;
• the first acceleration testing short joint and the second acceleration testing short joint are identical in structure;
• the first acceleration testing short joint comprises a cylindrical head and a threaded head;
• the threaded head is fixedly connected to the bottom of the cylindrical head;
• a top end of the cylindrical head is provided with a first threaded hole;
• a bottom of the threaded head is sequentially provided with a disc and an acceleration mounting frame;
• a left side and a right side of the acceleration mounting frame are planes;
• the left plane and the right plane are respectively provided with a radial acceleration sensor;
• two right angles which are staggered from each other are respectively arranged at a front side and a rear side of the acceleration mounting frame;
• a circumferential acceleration sensor is respectively mounted on the two right angles;
• the disc is provided with an axial acceleration sensor;
• the acceleration mounting frame is provided with a first through hole communicating with the first threaded hole;
• the damper comprises a barrel, an upper end cover and a lower end cover arranged in the barrel and positioned at the upper end and the lower end, a damping spring arranged in the barrel, a sliding sleeve and a guide shaft;
• the barrel is internally provided with a second threaded hole located above the upper end cover;
• the guide shaft is connected with the upper end cover;
• the guide shaft is internally provided with a second through hole communicating with the second threaded hole;
• the sliding sleeve sleeves the guide shaft and penetrates through the lower end cover;
• an extending-out end of the sliding sleeve is provided with an outer thread;
• the guide shaft is also sleeved with the damping spring which is pressed against between the sliding sleeve and the upper end cover;
• the outer thread of the sleeve is in threaded connection with the first threaded hole of the first acceleration testing short joint;
• the threaded head of the first acceleration testing short joint is in threaded connection with the second threaded hole of the barrel;
• the outer thread of the sliding sleeve is in threaded connection with the first threaded hole of the second acceleration testing short joint;
• the threaded head of the second acceleration testing short joint is connected with the perforating gun;
• a pressure sensor, the radial acceleration sensor, the circumferential acceleration sensor and the axial acceleration sensor are electrically connected with the signal amplifier respectively.