Testing method of breakthrough pressure of repeated fracturing plugging agent

Abstract

The invention discloses a testing method of the breakthrough pressure of a repeated fracturing plugging agent. The testing method comprises the following steps: (a) preparing the repeated fracturing plugging agent for future use; (b) selecting a plurality of rock core samples for future use; (c) respectively weighing rock cores and measuring lengths; (d) cutting each rock core along an axial direction and making an artificial crack; (e) paving one layer of particle substances on a crack surface and simulating a fracturing crack; (f) injecting the repeated fracturing plugging agent into the simulated fracturing crack and standing for a period of time; and (g) after the repeated fracturing plugging agent is gelled, testing the breakthrough pressure of the repeated fracturing plugging agent. According to the testing method disclosed by the invention, the breakthrough pressure of the repeated fracturing plugging agent can be rapidly detected; and the testing process is simple, the tested result is accurate, and the testing method provides data support to the utilization of the repeated fracturing plugging agent.

Description

technical field [0001] The invention relates to a method for testing the breakthrough pressure of a repetitive 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...

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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

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