Hydraulic fracturing construction method for heterogeneous stratum

Abstract

The invention discloses a hydraulic fracturing construction method for a heterogeneous stratum, belongs to the technical field of oil and gas exploitation equipment and construction, and solves the problems that in the prior art, the brittleness index of the heterogeneous stratum is obviously changed, and the construction cost is high, the occupied space is large and the construction quality is affected by adopting a slick water and linear glue alternate pump injection method. The method comprises the following steps that A, integrated variable-viscosity fracturing fluid is continuously mixed; B, the integrated variable-viscosity fracturing fluid is used for fracturing construction of a stratum; C, in the fracturing process, the viscosity of the integrated variable-viscosity fracturing fluid is changed according to the brittleness index of the corresponding stratum, so that the viscosity adapts to the brittleness index of the stratum; and D, fracturing construction of all stratums is completed in sequence. According to the method, by changing the addition amount of a variable-temperature variable-viscosity resistance reducing agent in the integrated variable-viscosity fracturing fluid, the viscosity of the fracturing fluid is changed, conversion between slick water and linear glue is achieved, the occupied space is saved, the construction quality is improved, and the method is suitable for fracturing construction of the heterogeneous stratums.

Description

technical field [0001] The invention belongs to the technical field of oil and gas exploitation equipment and construction, and particularly relates to a hydraulic fracturing construction method for heterogeneous formations. Background technique [0002] Hydraulic fracturing is an important construction method for transforming shale formations and exploiting shale gas. According to the different rock properties of shale gas reservoirs, different fracturing systems need to be selected. For formations with a higher brittleness index, a low-viscosity slickwater system is often used; for formations with a lower brittleness index, linear glue is usually used for fracturing construction. The rock properties of the formation are very complex, and the brittleness index is not a fixed value, but a range value, generally ranging from 20% to 80%. For heterogeneous formations, the change of the brittleness index is more obvious. Therefore, the selection of fracturing fluid is particul...

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Problems solved by technology

[0004] In view of the obvious changes in the brittleness index of heterogeneous strata in the prior art, the method of alternately pumping slick water + linear glue has high construction costs, takes up a large space and affects the construction quality. The present invention provides a method for heterogeneous strata. The purpose of the hydraulic fracturing construction method is: by adjusting the viscosity of the fracturing fluid, the fracturing fluid can realize the conversion of slick water and linear glue, so as to improve the construction quality and reduce the cost

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