Multi-lithology fracturing crack test method

Abstract

The invention discloses a multi-lithology fracturing crack test method. The method comprises the steps of (1) preparing a rock matrix: according to different rock mechanical parameters, adjusting the mass ratio of cement to quartz sand to water, and respectively preparing cuboid thin plates for simulating shale, coal rock and limestone; (2) crack system simulation: in a rock thin plate manufacturing process, simulating coal rock, shale bedding and coal rock cleat through preset paper sheets; (3) combining samples; (4) sample drilling: according to the well type characteristics of a horizontal well and a vertical well, drilling a counter bore with the length of 16 cm and the diameter of 14 mm in the surface of the sample in the direction parallel to or perpendicular to bedding, cementing a simulation shaft, and reserving a 2 cm open hole section at the lower part; (5) selecting the type of a proppant; (6) executing a sand adding process; and (7) evaluating the flow conductivity of the proppant. Therefore, the simulation method can quantitatively and accurately predict the real expansion track of the staged fracturing crack of the horizontal well.

Description

technical field [0001] The invention relates to the field of oil and gas reservoir development, in particular to a multi-lithology fracture test method. Background technique [0002] Fracturing physical simulation is an important laboratory method to reliably and effectively analyze the geometry and extension process of fractures. However, there is currently no fracturing physical simulation method for coal-measure composite reservoirs in multi-coal seam areas. [0003] Moreover, in the existing mining process, coal-measure composite reservoirs generally have the characteristics of low porosity and low permeability. Compared with conventional single lithology reservoirs, coal-measure composite reservoirs have distinct geological characteristics, and the lithology combination styles are diverse and complex. In particular, the rock mechanical properties and interlayer interface properties of different types of reservoirs are significantly different, which affects the extension...

AI Technical Summary

Problems solved by technology

[0007] To sum up, there are currently coexisting wells with various lithologies such as shale, coal rock, and sandstone, and multi-lithology fracturing fractures may expand in the multi-gas co-production system. Therefore, it is necessary to establish a multi-lithology fracturing fracture system , to solve the technical problem that the coal-measure composite reservoir is deeply buried underground, so that the geometry and extension of fractures cannot be directly observed

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