Proppant-carrying acid fracturing method for high-temperature ultra-deep carbonate reservoir

Abstract

The invention provides a proppant-carrying acid fracturing method for a high-temperature ultra-deep carbonate reservoir. The proppant-carrying acid fracturing method for the high-temperature ultra-deep carbonate reservoir comprises the following steps that (1) fracture forming is conducted through fracturing fluid; (2) ground crosslinked acid is adopted and is made to react with rock, so that an acid-etched fracture is generated in a formed fracture, and a proppant is carried with the ground crosslinked acid for supporting the acid-etched fracture; and (3) linear glue is used for replacement, and thus acid fracturing is completed. According to the proppant-carrying acid fracturing method for the high-temperature ultra-deep carbonate reservoir, the technique is simple, operation is convenient, and the construction effect is remarkable; and the proppant-carrying acid fracturing method is suitable for transforming construction of deep well carbonatite at the high temperature of 150-170 DEG C, a supporting fracture which has deep penetration and longer flow conductivity can be formed in a stratum, the productivity is increased and the production time is prolonged after acid fracturing and well fracturing, and the length of the formed fracture is larger than 120 m.

Description

technical field [0001] The invention relates to the technical field of reservoir stimulation and transformation, in particular to a ground cross-linked acid-carrying sand-carrying deep-penetration acid fracturing method that can be used in high-temperature ultra-deep carbonate reservoirs. Background technique [0002] The world's oil and gas reserves related to carbonate rocks account for 50% of the total reserves, and the production accounts for about 60% of the total production. Since 2000, domestic exploration and development of carbonate rock reservoirs has achieved rapid development. At present, 10% of my country's oil production and nearly 50% of natural gas production are produced in marine formations, mainly marine carbonic acid. salt rock. Due to the low permeability of carbonate rock matrix, acid fracturing or combined acid fracturing (combined acid fracturing and sand fracturing) has become the main stimulation measure for this type of oil and gas reservoirs. [...

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Problems solved by technology

[0007] Chinese patent document CN103374345A discloses an acid liquid system applied to acid fracturing of carbonatite reservoirs and its preparation. The jelly acid system consists of HCl with a mass concentration of 20% as 100% by weight to a mass concentration of 20%. Add 0.8% CYY-160, 1% CYY-1 crosslinking agent, 1% CYY-3 crosslinking retarder to HCl, used for acid fracturing and acid-carrying sand fracturing in carbonatite reservoirs at 90°C-140°C , but the corresponding process method is not provided, and it cannot meet the requirements of higher temperature reservoir acid fracturing

[0008] At present, high-temperature ultra-deep carbonate reservoirs lack experience in stimulation, and there is no effective acid fracturing technology with a temperature higher than 150°C and deep penetration suitable for it.

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