Method for filling refracturing plugging agent into single rock core

Abstract

The invention discloses a method for filling a refracturing plugging agent into a single rock core. The method includes (a) first conducting manual gap building on the single rock core; (b) adding filling substances in a gap; (c) filling solution into the gap till pressure is constant; and (d) filling the refracturing plugging agent into the gap till the pressure is constant and finishing the whole filling process. By means of the method, the refracturing plugging agent is successfully filled into the single rock core, filling effect is good, the gap can be successfully blocked after injection, and blocking cost of the single rock core is greatly reduced.

Description

technical field [0001] The invention relates to a method for injecting a single rock core of a repeated fracturing plugging agent. Background technique [0002] Due to poor reservoir physical properties, low oil well production, and complex pore structure and abnormal seepage state, the development characteristics of low-permeability reservoirs are very different from those of medium-high permeability reservoirs, and even qualitatively change. The development of low-permeability oilfields has the following basic characteristics: [0003] (1) The natural production capacity of the oil well is low, and it has industrial exploitation value only after fracturing; [0004] (2) The law of seepage does not follow Darcy's law and has a starting pressure gradient; [0005] (3) The natural energy is small, the pressure and output drop rapidly, and the primary recovery rate is low; [0006] (4) The water absorption capacity of the water injection well is low, and the starting pressu...

AI Technical Summary

Problems solved by technology

[0003] (1) The natural production capacity of the oil well is low, and it has industrial exploitation value only after fracturing;

[0004] (2) The law of seepage does not follow Darcy's law and has a starting pressure gradient;

[0005] (3) The natural energy is small, the pressure and output drop rapidly, and the primary recovery rate is low;

[0006] (4) The water absorption capacity of the water injection well is low, and the starting pressure and water injection pressure rise rapidly;

[0007] (5) The liquid production index of the oil well drops sharply after water breakthrough, making it very difficult to stabilize production

[0010] Oil, gas, and water wells after hydraulic fracturing, due to the limitations of fracturing technology, materials, equipment and tools at that time, were small in scale, improperly selected materials, and limited equipment power, etc., would lead to a significant reduction in the conductivity of hydraulic fractures and gradually Some of them are not effective due to improper well layer selection or operational reasons. At the same time, after long-term development, major oil and gas fields have entered the development stage of medium and high water cut periods, and it is becoming more and more difficult to achieve high and stable production. For this type of oil and gas Wells that require refracturing for high production and economic recovery