Hydration induction pretreatment and judgment method before fracturing of shale reservoir

Abstract

The invention discloses a hydration induction pretreatment and judgment method before fracturing of a shale reservoir. The hydration induction pretreatment and judgment method comprises the followingsteps that (1), a cable or a coiled pipe is adopted to conduct perforation operation on a first section of the reservoir; (2) the cable or the coiled pipe is taken out; (3) the displacement is slowlyincreased so as to pump clean water into a well shaft to conduct trial extruding, and the maximum displacement does not exceed 5m3 / min; (4) the clean water is pumped in the well shaft continuously; (5) after the clean water is pumped, a well is closed to wait for generation of a hydration reaction, and the hydration time is determined to be 10-18 hours through an indoor core hydration experiment;and (6) judgment is conducted on the in-site effect of pretreatment. According to the hydration induction pretreatment and judgment method, pretreatment is conducted on the shale reservoir before construction of main fracturing, thus the complexness of the fracture network of reservoir fracturing can be further improved, the seepage channels of reservoir fluid are increased, the seepage resistanceof the liquid is reduced, and achievement of yield maximization of a single well is facilitated. The method is high in in-site operability, and low in operation cost.

Description

technical field [0001] The invention relates to a new pretreatment method for increasing the complexity of reservoir fracturing fractures in the technical field of unconventional reservoir stimulation and transformation, in particular to a reservoir pretreatment and field effect evaluation method for increasing the complexity of shale reservoir fractures. Background technique [0002] The "Shale Gas Development Plan (2016-2020)" clearly proposes to perfect and mature shallow marine shale gas exploration and development technology below 3,500 meters, and to break through the exploration of deep marine shale gas, continental and marine-continental transitional shale gas exploration below 3,500 meters Develop technology; with policy support in place and market development going smoothly, strive to achieve 30 billion cubic meters of shale gas production in 2020. [0003] Hydraulic fracturing technology is a key technology for exploiting shale gas, and the complexity of the fract...

AI Technical Summary

Problems solved by technology

At present, relevant research at home and abroad is mainly focused on optimizing the main fracturing parameters (including pump injection displacement, type of pre-fluid, concentration of sand-carrying fluid, volume of sand-carrying fluid, type of proppant, etc.) to control the extension of hydraulic fractures to achieve The volume of stimulation and the complexity of fractures are maximized. However, the complexity of the final fracturing fracture network still cannot fully meet the production requirements, and no method has been found to pretreat the existing fracture network in the reservoir before the main fracturing

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