A water injection well expansion reservoir reconstruction method

Abstract

The invention belongs to the field of petroleum exploitation, and specifically relates to a method for expanding the capacity of a water injection well reservoir, comprising the following steps: S100, carrying out an in-situ stress test operation to measure the minimum principal stress and fracture pressure of the reservoir; S200, adopting a low-speed and pressure-controlled method The water injection method performs in-situ stress pretreatment on the reservoir, changes the original in-situ stress and water saturation of the reservoir around the wellbore, and increases the pore pressure of the reservoir around the well; S300, through the water injection method of hydraulic oscillation, expands the area with poor permeability of the reservoir, A preliminary expansion area is generated in the reservoir around the wellbore; S400 further expands the initial expansion area through stepwise large displacement and pressure-controlled water injection. The present invention not only avoids the disadvantages of short effective period of acidification and inconspicuous injection effect, but also protects the environment and reduces the cost.

Description

technical field [0001] The invention belongs to the field of petroleum exploitation, and in particular relates to a water injection well expansion reservoir transformation method. Background technique [0002] After the oil field is put into development, with the increase of production time, the energy of the oil layer itself will be continuously consumed, resulting in a continuous drop in the pressure of the oil layer, a large amount of degassing of the underground crude oil, an increase in the viscosity, a great reduction in the production of the oil well, and even the stop of spraying and production, resulting in underground A large amount of dead oil remains and cannot be recovered. In order to make up for the underground deficit caused by the extraction of crude oil, maintain or increase the pressure of the reservoir, achieve high and stable production of the oilfield, and obtain a high recovery rate, the oilfield must be developed by water injection. [0003] After a ...

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Problems solved by technology

Similar to the present invention, the method of increasing injection used in many oilfields at present with certain effects is the oscillating injection technique using ultrasonic waves. However, due to the rapid attenuation of ultrasonic energy and the relatively short propagation distance of sound waves in the formation, it is not suitable for deep plugging of water wells. Unblocking, and the construction is not very convenient

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