Method for measuring filtration coefficient of supercritical carbon dioxide fracturing fluid

Abstract

The invention belongs to the technical field of unconventional oil and gas stimulation, particularly relates to a method for measuring a filtration coefficient of supercritical carbon dioxide fracturing fluid, and aims to determine the filtration coefficient of supercritical carbon dioxide fracturing fluid. The method comprises the following steps: (1) placing cores; (2) exhausting gas in an upper chamber of an intermediate container, and filling methane into the upper chamber of the intermediate container; (3) applying pressure to a lower chamber of the intermediate container; (4) injecting methane into the cores; (5) emptying methane in the upper chamber of the intermediate container, and injecting carbon dioxide; (6) applying confining pressure; (7) applying back pressure; (8) injecting carbon dioxide to the cores; (9) calculating the filtration rate and filtration coefficient. According to the method for measuring a filtration coefficient of supercritical carbon dioxide fracturing fluid, the temperature and pressure are adjustable, the high-temperature and high-pressure environment requirements for carbon dioxide to reach the supercritical state are met, and the filtration law of supercritical carbon dioxide fracturing fluid at different temperatures can be studied truthfully.

Description

technical field [0001] The invention belongs to the technical field of unconventional oil and gas stimulation, and in particular relates to a device and method for measuring the fluid loss coefficient of supercritical carbon dioxide fracturing fluid, which is used to study the fluid loss of supercritical carbon dioxide fracturing fluid in unconventional oil and gas fracturing stimulation engineering To determine the fluid loss coefficient of supercritical carbon dioxide fracturing fluid. Background technique [0002] Supercritical carbon dioxide (SC-CO 2 ) fracturing is a new type of unconventional oil and gas reservoir stimulation technology. It has a series of advantages that cannot be compared with conventional hydraulic fracturing technology. means. [0003] Supercritical carbon dioxide fracturing fluid has many characteristics such as less formation damage, viscosity reduction, anti-swelling, resistance reduction, and drainage aid. When the injection volume is constan...

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Problems solved by technology

Excessive fracturing fluid fluid loss will also lead to gradual accumulation of proppant, increasing the proppant content in fractures, prone to sand plugging, and wellbore collapse

After fracturing, under a certain fluid loss rate, the formed fractures can be closed in time, but when the fluid loss rate is too slow, the proppant will quickly deposit in the fracture, which will affect the uniform distribution of proppant in the fracture, and cannot Supporting the entire height of the fracture, the width of the fracture becomes narrower, and the stimulation effect is not ideal

Therefore, the key parameter for optimal design of fracturing hydraulic parameters using supercritical carbon dioxide fracturing is to determine the fluid loss coefficient of supercritical carbon dioxide fracturing fluid; at present, there are no reports on the fluid loss performance of supercritical carbon dioxide fracturing fluid in China

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