Process method for increasing ultra-deep carbonate reservoir reconstruction fracture length

Abstract

The invention discloses a process method for increasing ultra-deep carbonate reservoir reconstruction fracture length, and belongs to the field of oil and gas exploitation. The method comprises the steps that a cross-linking fracturing fluid is injected into a stratum through an oil pipe to form a crack; a sand-carrying cross-linking fracturing fluid is injected into the stratum through the oil pipe; an authigenic acid fracturing fluid is injected into the stratum through the oil pipe, wherein the authigenic acid fracturing fluid is used for forming acid at the temperature of the stratum and etching the wall surface of the crack; preset acid is injected into the stratum through the oil pipe; and slickwater is injected into the stratum through the oil pipe. According to the method, the end,the middle and the root of the fracture are reconstructed through the sand-carrying cross-linking fracturing fluid, the authigenic acid fracturing fluid and the preset acid, so that the effective fracture length and the flow conductivity of the fracture are improved, and a carbonate reservoir with the large depth can be effectively reconstructed; the problem that related technologies are difficult to adapt to the ultra-deep carbonate reservoir is solved; and the effect of performing effective acid fracturing on the ultra-deep carbonate reservoir is achieved.

Description

technical field [0001] The application relates to the field of oil and gas exploitation, in particular to a process method for increasing the length of fractures in ultra-deep carbonate reservoirs. Background technique [0002] Carbonate reservoirs occupy an important position in the distribution of oil and gas in the world. Its oil and gas reserves account for about 50% of the world's total oil and gas reserves, and its oil and gas production accounts for more than 60% of the world's total oil and gas production. [0003] A composite acid fracturing method for carbonate rock reservoirs comprises: 1. 3 / min displacement to inject the ground cross-linked acid into the formation; 2. Mix the fracturing fluid gel with sand, 3 / min displacement into the formation; 3. 4.0-5.5m 3 / min displacement into closed acid, the sand-carrying fluid formed by mixing fracturing fluid jelly and sand is displaced into the formation, and when the artificial fractures formed reach 130 meters or ...

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Problems solved by technology

[0004] In the process of realizing this application, the applicant found that the relevant technology has at least the following problems: the above-mentioned acid fracturing method is difficult to apply to ultra-deep carbonate reservoirs

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