Testing device and method for horizontal fracture dominant seepage channel

Abstract

The invention relates to a testing device and method for a horizontal fracture dominant seepage channel, and belongs to the field of oil-gas field development. The device is sequentially connected with a nitrogen container (17), a booster pump (19), a gas inlet pipeline valve (20), a rock sample block a (7), a rock sample block b (11), an artificial crack (8), a monitoring joint (10) and a DAS monitoring system (9). And the jack a (6) and the jack b (15) provide closing pressure for the artificial crack (8). Confining pressure is applied to the artificial crack (8) through the jacks a and b, and the crack forms a flow guide channel under the filling action of the propping agent (30). A DAS monitoring system (9) formed by using an optical fiber (25) as a sensor monitors nitrogen flow and sound volume at different diversion channel sections, and evaluates the diversion capability of the dominant seepage channel. The influence of the stratum on the conductivity of the advantageous seepage channel under different types of proppants, particle size combinations, sanding concentrations and confining pressures can be simulated, and finally the optimal conductivity is optimized.

Description

technical field [0001] The invention relates to a seepage test device, in particular to a test device and method for dominant seepage channels in horizontal fractures, belonging to the technical field of oil and gas field development. Background technique [0002] At present, hydraulic fracturing technology is often used in the geological development of unconventional reservoirs. This technology uses surface high-pressure pumps to inject high-viscosity liquid into the well at a displacement that greatly exceeds the absorption capacity of the formation. When this pressure is greater than the in-situ stress near the borehole wall and the tensile strength of the formation rock, fractures will occur in the formation near the bottom of the well. Continue to inject the sand-carrying fluid with proppant, the fracture extends forward and is filled with proppant, and after the well is shut in, the fracture is closed on the proppant, thus forming a sand-pack with a certain geometric s...

AI Technical Summary

Problems solved by technology

However, for horizontal fractures, under actual working conditions, the final result of proppant transport is placed on the lower edge of the fracture due to gravity, and it is impossible to cover the entire fracture area; at the same time, the closure pressure is also a triaxial stress state, and the fracture closure process In the middle, under the influence of horizontal stress, there is no proppant in the upper edge of the fracture, and the fracture closes quickly. There is proppant in the lower edge of the fracture, and the fracture is supported under the action of proppant. Therefore, the proppant at the lower edge may Migration occurs

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