A carbon dioxide anhydrous fracturing fluid damage testing system and method

Abstract

A CO2 anhydrous fracturing fluid damage test system comprises a liquid CO2 supply system and a reagent supply system, wherein outlets of the liquid CO2 supply system and the reagent supply system are both connected to input ends of a common core holder branch and a long core holder branch which are connected in parallel, a preheater is arranged on a connecting pipeline, and output ends of the two branches are connected with a fracturing fluid recovery device; the common core holder branch comprises a common core holder, and a first pressure difference transducer is connected between the input end and the output end of the common core holder; the long core holder branch comprises a long core holder, and a second pressure difference transducer is connected between the input end and the output end of the long core holder. The invention further provides a test method based on the system. By means of the method, the reservoir core damage degree of the CO2 anhydrous fracturing fluid under the conditions of different displacement, different temperature, different pressure as well as different ratios of the liquid CO2 to corresponding fracturing fluid additives can be simulated and tested.

Description

technical field [0001] The invention belongs to the technical field of carbon dioxide anhydrous fracturing, in particular to a carbon dioxide anhydrous fracturing fluid damage testing system and method. Background technique [0002] As a new fracturing technology—carbon dioxide anhydrous fracturing technology is gradually entering the public's field of vision. CO 2 Waterless fracturing technology mainly uses CO 2 Anhydrous fracturing fluid (mainly composed of liquid CO 2 Formed by mixing with a very small amount of chemical additives) instead of traditional water-based fracturing fluids, it has the characteristics of "waterless fracturing", which can obviously eliminate the water sensitivity and water lock damage of conventional fracturing fluids to reservoirs, replenish formation energy, and improve fracturing stimulation. effect, and the fracturing fluid has no residue, which can effectively protect the reservoir and save a lot of water resources. [0003] However, the...

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Problems solved by technology

[0003] However, the existing instruments for testing the damage performance of common fracturing fluids to oil and gas reservoirs are mainly aimed at testing the damage characteristics of conventional liquid fracturing fluids, such as jelly fracturing fluids, or clean water fracturing fluids. There are no mature products on the market for systems and equipment that are harmful to reservoirs by fracturing fluids

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