High temperature and high pressure wells put forward higher requirements for the premium connection. The manufacturer of the premium connection should not only pay attention to the preparatory work, screw joint design and quality assurance procedures in the early planning stage, but also run through all links of product processing, transportation and well pad.
In order to prove its high reliability and applicability, it is necessary to conduct a comprehensive physical test and evaluation test on the threaded joint used in high temperature and high pressure wells. The appropriate test level shall be selected according to the joint test under service conditions, and the supplementary test evaluation procedure shall be formulated according to iso13679:2002 standard to provide reliable load envelope test. In the selection and evaluation of premium connection for high temperature and high pressure wells, the following experience is worth learning:
1. According to the load and pressure of the specific high temperature and high pressure well, it is necessary to add the supplementary test procedure in the thread joint evaluation of high temperature and high pressure well.
2. When the pressure difference in the string is greater than 55.16mpa in the high temperature and high pressure well, two independent premium connections with sealing structure that have passed the test are selected.
3. The leakage probability of the whole string can be greatly reduced by testing and evaluating each sealing structure of the double pole sealing screw joint separately.
4. The premium connection of two-stage sealing structure through independent test will be less affected by quality assurance, quality control and transportation link errors than that of single sealing structure.
5. Although the price of purchasing double stage sealing structure threaded joint pipe is slightly higher, these increased costs are quite small compared with the cost of control treatment or blowout treatment after a well fails, especially in the gas wells with high temperature and high pressure.