Method for exploiting common thickened oil by utilizing high-permeability strip

Abstract

The invention belongs to the technical field of oil and gas field development engineering, and particularly relates to a method for exploiting common thickened oil through a high-permeability strip. The method is suitable for common heavy oil reservoirs subjected to displacement exploitation, and fluid channeling and high-permeability strip development have been formed in reservoirs. According tothe method, a one-injection one-production or multi-injection multi-production production mode is adopted, huff-puff and displacement alternate production is carried out, a high-permeability strip serves as a crude oil gathering area in the huff-puff stage and an oil displacement channel in the displacement stage, well group overall huff-puff and well group oil displacement are carried out in stages, and crude oil in the stratum adjacent to the high-permeability strip is exploited. By means of the method, crude oil in the area adjacent to the high-permeability strip can be used more efficiently, sweep efficiency is improved, and the recovery ratio is increased.

Description

technical field [0001] The invention belongs to the technical field of oil and gas field development engineering, and in particular relates to a method for exploiting ordinary heavy oil by using high-permeability strips. Background technique [0002] With the rapid development of the global economy, the difficulty of developing conventional oil and gas resources is gradually increasing, facing problems such as the decline in oil recovery, and heavy oil resources have attracted widespread attention from the world due to their rich reserves. [0003] Ordinary heavy oil refers to heavy oil with a viscosity of 50-10000mPa·s under reservoir conditions. This type of reservoir crude oil has certain fluidity under reservoir conditions. Some reservoirs can be flooded by water, gas or chemical agents. And other cold mining methods for development. Due to the heterogeneity of reservoirs in most reservoirs, with the development of high-permeability strips, channeling will gradually for...

AI Technical Summary

Problems solved by technology

However, in this process, due to the complexity of the formation conditions, the plugging agent injected into the formation is prone to failure, and the plugging range is very limited, concentrated near the wellbore, and in the later stage of construction, the injected fluid is easy to bypass the plugging agent and further form channeling , causing blocking failure

In addition, the plugging of the hyperpermeable zone leads to an increase in fluid injection pressure in the later stage of development, which increases the requirements for ground injection equipment

[0006] Chinese patent CN105952425B relates to a chemical agent assisting CO 2 A method for improving the recovery of ordinary heavy oil reservoirs by huff and puff, the method is to carry out CO 2 Chemical agents are added during the huff and puff process, and the foam formed by the chemical agents in the formation can effectively suppress CO 2 Gas channeling, through the synergistic effect of gas and chemical agents, blocks the high-permeability zone, expands the sweeping range of the near-wellbore area, and improves the oil washing efficiency. The remaining oil in the near-well area cannot effectively spread and exploit the crude oil between two production wells

[0007] It can be seen from the above that the existing technology is basically to seal the high-permeability zone, because the injected material in the displacement production tends to enter the high-permeability zone first, so the oil in the high-permeability zone is produced first, and the other high-permeability zone After the oil production in the zone is completed, the injected material still enters the high-permeability zone without affecting the oil in the low-permeability layer. At this time, the injected material is likely to go directly from the injection well to the production well along the high-permeability zone, making an ineffective circulation. It cannot effectively drive oil, so the purpose of plugging is to prevent the injected materials from displacement production from continuing to enter the high-permeability zone, but to force them to enter the low-permeability layer for oil displacement

However, the seepage capacity of hyperpermeable strips is relatively strong, so it is more difficult to effectively seal them

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