Self-supporting fracturing fluid system for modifying unconventional reservoir fracture network segment

Abstract

The invention discloses a self-supporting fracturing fluid system for modifying an unconventional reservoir fracture network segment, which comprises a fracture network segment self-supporting fracturing fluid and a fracture network segment channel fracturing fluid mutually insoluble. The fracture network segment self-supporting fracturing fluid is prepared from the following components in parts by weight: 10 to 40 parts of polyphenyl ether, 10 to 20 parts of dicumyl peroxide, 10 to 50 parts of triallyl isocyanurate, 40 to 90 parts of styrene, 1 to 10 parts of a surfactant and 50 to 500 parts of a solvent. The fracture network segment channel fracturing fluid comprises the following components in parts by weight: 1-50 parts of a resistance reducing agent, 10-100 parts of potassium chloride, 100-900 parts of clear water, 1-10 parts of a quaternary ammonium salt cationic polymer, 1-100 parts of polyethylene glycol and 5-500 parts of lauryl sodium sulfate. The method can greatly improve the flow conductivity of the fractures of the main fracture segment of volume fracturing, and eliminates the risk of sand blocking.

Description

technical field [0001] The disclosure belongs to the technical field of oilfield development, and in particular relates to a self-supporting fracturing fluid system used for reforming fractured network sections of unconventional reservoirs. Background technique [0002] The production increase of oil and gas fields can be achieved by injecting fracturing fluid into the reservoir to recreate fractures, that is, using the ground high-pressure pump set to squeeze liquid with a certain viscosity ( fracturing fluid) to gradually increase the pressure in the wellbore. When the pressure increases above the fracture pressure of the reservoir, the reservoir will form one or more main fractures at the proximal end (near the source of the fracturing fluid squeeze), and force the formation of secondary fractures at the far end and laterally of the main fractures. Fractures, and continue to branch on the secondary fractures to form secondary secondary fractures, and finally form a compl...

AI Technical Summary

Problems solved by technology

The construction technology of alternately injecting slick water is relatively complicated and the efficiency is low

[0007] (2) The utilization rate of complex fractures after fracturing is low, and the volume of stimulation is insufficient

[0008] Since the fractures formed in the fracture network segment are secondary fractures and secondary secondary fractures, these fractures have irregular shapes, high complexity, small opening (fracture width), and are far away from the main fractures, so it is difficult for proppant to enter, resulting in many fractures. The fractures opened cannot be effectively filled. After fracturing, many fractures are gradually closed under the closing pressure, so the total stimulated volume is insufficient.

[0009] (3) The diversion capacity is low, and the increase in production capacity is limited

[0010] Due to the poor sand-carrying capacity of slick water, only silt and silt can be carried to add sand, and the average sand ratio can only be controlled at 3-5%, so the conductivity of sand-filled cracks is greatly limited

The conductivity of these sand-filled fractures is not enough for the exploitation of unconventional natural gas, and it is far from meeting the demand of unconventional oil resources for fracture conductivity

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