The application discloses a
pipe string structure and a control method for self-flow gas injection from a high-pressure layer to a low-pressure layer, and improves technical problems such as high well completion operation cost and great process difficulty. The
pipe string structure comprises a
wellbore casing, an isolation
assembly, a filter
assembly and a gas injection
assembly. The gas injection assembly comprises: a gas injection production
pipe string arranged in the
wellbore casing; a
production packer arranged on the gas injection production pipe string and fixedly seated with the
wellbore casing, and the
production packer is located above a low-pressure layer of a formation; a distribution and injection valve arranged on the gas injection production pipe string and located below the
production packer, and the distribution and injection valve is located at the low-pressure layer of the formation; and a sealing part connected to the bottom of the gas injection production pipe string and sealingly connected with the isolation assembly. The application can realize self-flow of
natural energy of a high-pressure layer gas group to a low-pressure layer gas group in the same well, improve the
recovery rate of the low-pressure layer gas group, save cost and reduce the well completion process difficulty, and the
oil well can be subjected to separate layer exploitation in the later period.