Self-born acid composite acid fracturing process for high-temperature deep well carbonate rock reservoir

Abstract

The invention relates to a self-born acid composite acid fracturing process for a high-temperature deep well carbonate rock reservoir. The process comprises the following work procedures of: (1) injecting slick water into a stratum through an oil pipe; (2) injecting non-crosslinked fracturing liquid into the stratum through the oil pipe; (3) injecting a self-born acid system into the stratum through the oil pipe; (4) injecting a gelled acid system into the stratum through the oil pipe in a low-displacement mode; and (5) injecting the slick water into the stratum through the oil pipe, wherein the volume proportions of liquid, accounting for the total liquid injected into the stratum, injected in the first to fifth work procedures are shown as follows: the slick water in the first work procedure accounts for 3 to 10 percent; the non-crosslinked fracturing liquid in the second work procedure accounts for 40 to 60 percent; the self-born acid system in the third work procedure accounts for 30 to 50 percent; the gelled acid system in the fourth procedure accounts for 3 to 10 percent; the volume proportion of the slick water in the fifth work procedure is 3 to 15 percent; and the volume unit is m<3>. Through the self-born acid composite acid fracturing process, the flow guide capability is improved by more than 140md.m, and the deep penetration effect of the high-temperature deep well carbonate rock reservoir is obvious.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to an authigenic acid composite acid fracturing process for high-temperature deep well carbonate reservoirs. Background technique [0002] my country's deep carbonate reservoirs have the characteristics of deep burial, serious reservoir heterogeneity, and poor oil-bearing matrix. It is difficult to obtain ideal results by a single acid fracturing process or acid system. Composite acid fracturing technology is a new type of oil and gas well stimulation and water well injection technology produced in the late 1980s. This technology complements the advantages of different stimulation technologies when performing reservoir stimulation on oil and water wells, and more effectively Achieve increased production and injection. The application of composite acid fracturing technology has greatly improved the scale and conductivity of acid-etched fractures, and basically ...

AI Technical Summary

Problems solved by technology

[0005] At present, the conventional authigenic acid system is mainly used for acidizing sandstone reservoirs, and the combined acid fracturing technology of authigenic acid has not yet been researched and applied in carbonate reservoirs

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