Experimental device for simulating spreading of propping agent in crack and application thereof

Abstract

The invention relates to an experimental device for simulating the spreading of a propping agent in a crack, which comprises an artificial crack, the artificial crack comprises two mutually-parallel transparent plates, the upper and lower ends of the two transparent plates are sealed respectively by an edge-coating frame, the left end of each transparent plate is provided with a simulated shaft, the right end of the transparent plate is provided with a liquid outlet pipe, and the transparent plates, the edge-coating frames, the walls of the simulated shafts and the walls of the liquid outlet pipes define a closed space. According to the invention, under the condition of taking different crack widths, crack surface coefficients, sand expansion ratios, fracturing-fluid leak-off levels, friction resistances in cracks and the like into consideration, the experimental device simulates the spreading situation of a propping agent in the artificial crack, therefore, the experimental device accurately simulates the situations of cracks in stratums, and the accuracy is greatly improved.

Description

technical field [0001] The invention relates to an experimental device for simulating the laying of proppant in fractures and its application, belonging to the technical field of oil and gas field development and research. Background technique [0002] In hydraulic fracturing, the placement of proppant in the fracture plays a critical role in the success of the operation. During the fracturing process, the sand mixing fluid is pumped into the fracture, and under the influence of gravity, buoyancy, liquid carrying capacity in the horizontal direction, and viscous resistance, the proppant has a concentration difference on the vertical section of the fracture, from top to bottom. The bottom can be divided into no-sand area, suspension area, particle tumble area, and sand embankment. During on-site construction, the proppant may all settle to the bottom of the fracture, resulting in no proppant filling in the upper part of the fracture, thus forming invalid fracture support, wh...

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Problems solved by technology

3. The core components of the experimental device are completely different

There are concentric cylinder devices and flat-plate devices for studying this law in foreign countries. However, the experimental devices do not determine the indoor simulation parameters according to the principle of similarity, and are small in size. They can only conduct simple research on the settlement of proppant, and cannot study the sand. In addition, the model does not take into account the roughness of the fracture wall, the leakage of fracturing fluid in the fracture, and the aperture, phase and density of the perforation holes in the wellbore, so it is quite different from the actual situation.

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