The method of selection optimal program of bringing the well on to production in the Achimov tight-oil reserves

Introduction. Due to technological and geological factors, there is a high rate of decrease in well productivity at the Achimov tight-oil reserves. The development at a large gas-condensate field with these reserves was often accompanied by hydrate formation, a stop of blowing and a drop in productivity with an intensive decrease in bottom-hole pressure.

Aim. To develop a methodology for selecting the optimal stabilization program for the project well, taking into account the experience of existing wells.

Materials and methods. The methodology includes assessment of hydrate formation conditions, evaluation of the possibility of blowing, and determination of allowable drawdown pressures. Hydrate formation conditions are assessed using a hydrate curve. Blowing conditions are evaluated using vertical lift performance (VLP) curves, where zones of stable blow, unstable blow, and a zone where liquid begins to accumulate at the bottom-hole, leading to blow cessation, are identified based on the slope angle. The minimum allowable bottom-hole pressure is determined based on the operating experience of existing wells, which shows that further bottom-hole pressure reduction leads to decreased productivity due to rock matrix compressibility and impaired proppant properties.

Results. The low productivity of the project well leads to the need to inject high-concentration methanol due to hydrate formation, as well as to short-term blowing. At the same time, lowering the downhole pressure below the threshold value of 300 bar is not recommended, as this will lead to an intense drop in well productivity.

Conclusion. The development of a methodology for determining stabilization program for wells allows you to maximize production and maintain well productivity for further work and research. The methodology tested in the above work is particularly relevant for vertical wells in low-permeability reservoirs, which, due to geological and technological factors, have low flow rates, which leads to their unstable recovering

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