Russian scientists have increased the productivity of an oil well.

Improperly selected operational parameters for an oil well can reduce its productivity by up to 15 percent. To establish hydrodynamic connectivity between the reservoir and the well, perforation work is carried out to create channels that facilitate fluid movement during production. The process can be managed through pressure differentials. Researchers at Perm Polytechnic University have developed a model of the near-wellbore zone, which includes the production casing, cement stone, and a section of the reservoir rock with perforation holes. This model has enabled the identification of the most optimal operational parameters for maximizing hydrocarbon extraction efficiency.

2024-12-10 10:00:35https://naked-science.ru/article/column/produktivnost-neftyanoj-s

One of the most common methods for establishing hydrodynamic communication between a reservoir and a well is cumulative perforation, during which a perforator is lowered into the well on an electric cable. The explosion from its charges creates a directed jet that forms channels.

The difference in pressure between the liquid column in the well and the reservoir is referred to as depression. A drawback of cumulative perforation is that it alters the stress-strain state of the casing, cement stone, and reservoir rock near the drilled channels. This leads to a decrease in the permeability of the rocks and the overall productivity of the well.

To study the impact of such changes on rock permeability, as well as the likelihood of developing weakened or destructible areas, scientists from Perm Polytechnic conducted numerical modeling of the near-wellbore zone.

“The results obtained confirmed the necessity of selecting an optimal operating mode for production wells to prevent intense compaction of the reservoir due to increased effective stresses from reduced bottom-hole and reservoir pressures,” explains Sergey Popov, head of the laboratory at the Institute of Oil and Gas Problems of the Russian Academy of Sciences and Doctor of Technical Sciences.

“As the difference between reservoir and bottom-hole pressures increases, the destruction from tensile stresses decreases. At a depression value of 9 MPa, such zones completely disappear, leaving only areas of destruction from compression, which, on the contrary, increase,” comments Sergey Chernyshev, head of the Department of Oil and Gas Technologies at PNIPU and Doctor of Technical Sciences.

“We found that when the depression on the reservoir rises to 12 MPa, the maximum reduction in the well productivity coefficient can reach 15 percent, indicating the need to search for an optimal operating mode for the production well,” adds Vadim Derendyaev, assistant at the Department of Oil and Gas Technologies at PNIPU.

The research conducted by the scientists at Perm Polytechnic allowed them to determine the influence of depression on the productivity coefficient using a developed numerical model, which can be taken into account in future efforts to select an effective extraction mode.

The article is published in the journal “Geology, Geophysics and Development of Oil and Gas Fields.” The research was conducted as part of the “Priority 2030” program.