News from this newspaper: Recently, the first toothless hydraulic power pliers designed and developed by the Central Plains Petroleum Engineering Underground Special Operation Company appeared in the Central Plains, and was successfully applied in the 23-36 well of the gas storage tank, marking a breakthrough in the technology of toothless pipe operation in the Central Plains underground.

  Wen 23-36 well is an observation well deployed by the national pipe network in the Wen 23 gas storage depot. The first set of toothless hydraulic power pliers is used for lower pipe construction under the Central Plains. All the indicators meet the technical requirements of construction, which has been highly praised by Party A's on-site supervision.

   In the construction of gas storage depots, oil pipes and casings containing 13Cr (chromium) of anti-corrosion alloy materials are generally used to extend the production life of the well. However, compared with ordinary oil pipes, this alloy material is softer. When using conventional hydraulic power pliers to operate on the lower pipe, it is easy to leave "dent marks" in the galvanized layer on its surface, thus accelerating the corrosion of oil and casing and reducing the service life of the gas reservoir.

  This kind of equipment cannot meet the high standard requirements of "no tooth marks" at the gas storage site.

  Where there is difficulty, there are challenges. Zhongyuan Underground organized relevant experts to conduct in-depth research and compiled standard and detailed technical requirements. Finally, the XQ140/30 toothless hydraulic power forceps were successfully produced by means of public bidding.

  Compared with micro-tooth marks hydraulic power pliers, tooth-free hydraulic power pliers completely abandon traditional metal "teeth". Both semicircular tooth plates and clamp teeth are made of special polymer elastic materials. Thousands of granular pliers are embedded on the surface of the tooth plate. These small "teeth" are closely adhere to the tubing and casing surface to reduce stress concentration on the contact surface, thus protecting the surface of the tubing and casing from damage.

  At the same time, toothmarkless hydraulic power pliers carry out full wrapping of the pipe column. Because there are many contact points between the dental plate and the surface of the pipe column, it presents "surface" contact, not "point" contact. The stress applied to the circular direction of the column is very balanced, which will not deform the pipe column in the clamping part, nor will it cause destructive damage to the surface of the tubing pipe.

  In addition, the toothless hydraulic power forceps scientifically and reasonably set up and controlled the torque and rotation speed of the unloading buckle on the tubing and casing, which reduces the probability of surface bonding of the tubing and casing buckle and the damage to the sealing surface, and greatly prolongs the service life of the tubing and casing.

  (Huang Yingying, Dong Xin)   Source: Sinopec (6.480, -0.03, -0.46%)