Oil-gas well hydraulically-created-fracture expansion visualization experiment method and oil-gas well hydraulically-created-fracture expansion visualization experiment device

Abstract

The invention relates to an oil-gas well hydraulically-created-fracture expansion visualization experiment method and an oil-gas well hydraulically-created-fracture expansion visualization experiment device. The device is composed of a rock sample chamber, a crustal loading unit, a simulation fracturing string, a high-speed camera, a high-pressure pumping unit, a data measuring and collecting unit and the like, and four transparent observation ports are formed on a top cover of the rock sample chamber. The method includes firstly, preparing a flat-plate-type rock sample, performing high-pressure-water cutting to preform a natural fracture, and filling the natural fracture with epoxy resin to form a filled-type fracture; secondly, performing water saturation on the rock sample for 3-5 days, and using epoxy resin to wrap the rock sample after water saturation; thirdly, loading three-axis stress on the rock sample, drilling a borehole under the condition that the three-axis stress is applied on the rock sample, and mounting the simulation fracturing string; finally, connecting a high-pressure pipeline with a constant-flux pump, pumping fracturing liquid, recording a fracture expansion path by the high-speed camera, and measuring pumping pressure changes by a pressure transmitter. By the method and the device, the hydraulically-created-fracture expansion path can be visualized on a plane, and a novel experiment method is provided for studying on a hydraulically-created-fracture expansion mechanism.

Description

technical field [0001] The invention relates to a visual experiment method for hydraulic fracturing crack expansion of oil and gas wells, and provides an experiment device suitable for the method, which belongs to the field of oil exploitation. Background technique [0002] Hydraulic fracturing is a widely used oil and gas well stimulation technology in oil production, especially in low-permeability oil and gas reservoirs and unconventional gas reservoirs such as shale gas and coalbed methane, which have achieved good stimulation effects. Its basic principle is to inject a large volume of fracturing fluid (liquid or gas) into the wellbore through the surface high-pressure pump group, causing formation rocks to form tension or shear fractures under the action of fluid pressure, and finally form fractures with A network of man-made fractures with a certain conductivity. [0003] The research on the mechanism of hydraulic fracturing fracture propagation has always been a hot a...

AI Technical Summary

Problems solved by technology

[0012] In order to overcome the shortcomings of the existing experimental methods, such as the inability to directly observe the fracture propagation path, the difficulty in simulating the pore pressure, the inability to realize the filling of natural fractures, and the inability to reflect the impact of drilling on the disturbance of the in-situ stress field, the present invention provides a hydraulic fracturing fracture for oil and gas wells. Extending the visualization experiment method while providing an experimental setup suitable for the above method

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