A supplementary energy fracturing method for low-pressure tight oil reservoirs

Abstract

The invention discloses a low-pressure tight oil reservoir replenishment energy fracturing method, which comprises the following steps: deploying several long horizontal wells in the low-pressure tight oil reservoir, the shafts of the long horizontal wells are all parallel to each other, and the shafts of the long horizontal wells are all perpendicular to the formation The direction of the maximum principal stress; precise fracturing of each long horizontal well through dense cutting; through the full three-dimensional fracturing software simulation, the fracturing fractures can completely cover all long horizontal wells and each long horizontal well section. The amount of liquid injected into the ground; calculate the amount of additional liquid injected into the ground when the formation pressure within the range of the long horizontal well reaches the preset multiple of the original formation pressure; all long horizontal wells are fractured according to the amount of liquid injected into the ground and the amount of added ground fluid. The invention can slow down the production decline of the low-pressure tight oil reservoir, prolong the stable production period, improve the recovery degree, and increase the cumulative production of a single well in the whole life cycle of a single well.

Description

technical field [0001] The invention belongs to the field of oil and gas field exploration and development, and relates to a method for replenishing energy fracturing of low-pressure tight oil reservoirs. Background technique [0002] At present, low-pressure tight oil reservoirs are mainly developed by quasi-natural energy in horizontal wells or by water injection in vertical wells and oil recovery in horizontal wells. [0003] However, under the condition of quasi-natural energy development after volume fracturing in horizontal wells, the initial production is high, but due to lack of energy supplement, the production declines greatly, with an annual decline rate of about 40%, and the final recovery rate generally does not exceed 25%. Under the condition of oil production and development of horizontal wells, although the formation energy has been replenished, the injected water expands radially, the sweep area is limited, the remaining oil area is large, and the horizontal...

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Problems solved by technology

[0003] However, under the condition of quasi-natural energy development after volume fracturing in horizontal wells, the initial production is high, but due to lack of energy supplement, the production declines greatly, with an annual decline rate of about 40%, and the final recovery rate generally does not exceed 25%. Under the condition of oil production and development of horizontal wells, although the formation energy has been replenished, the injected water expands radially, the sweep area is limited, the remaining oil area is large, and the horizontal wells are easy to see water, resulting in high water cut and even violent water flooding. The degree of extraction is only about 30%

It can be seen that the annual decline rate of these two oil recovery development methods is high and the cumulative oil production is low

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