Pumping stop sand setting fracture-height-controlling acid fracturing process method applicable to carbonate reservoir

Abstract

The invention relates to a pumping stop sand setting fracture-height-controlling acid fracturing process method applicable to a carbonate reservoir. The method comprises the following work procedures that before the normal fracturing, low-viscosity slickwater is adopted for fracture making, and the initial fracture height is controlled; then, after the slickwater enters the stratum in a way of carrying support agent sand, the pumping stop is adopted for prompting the support agent sand to be settled near a fracture opening, so that each stage of support agent sand shields the back section in advance, a high-intensity artificial separation layer is formed, the stress state is changed, and the goal of effectively controlling the lower fracture height extending to prevent the communication with the lower part water body is achieved; low-viscosity fracturing fluid is injected for fracture making at a stable discharge capacity; after the fracturing fluid enters the stratum, acid liquid is injected for etching the stratum, and high-flow-guide capability artificial fractures are formed; after the acid liquid is extruded into the stratum, the pumping is stopped for measuring the pressure drop, and the construction is completed. The process has the advantages that the artificial separation layer can be formed, the fracture height vertical direction extending can be controlled, the stress state is changed, and the goals of effectively controlling the lower fracture height extending and preventing the communication with the lower part water body are achieved.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to a high-acid pressure process method suitable for pump stop sand settling and fracture control for carbonate rock reservoirs. Background technique [0002] The pump-stop sand settling fracturing process is the development of the technology of artificially controlling the fracture height, and is another innovation of the fracturing process. It comprehensively applies the conventional technology of controlling the fracture height, and uses ceramsite or quartz sand instead of silt as the sinking agent. The mechanical state of the rock and the flow path of the fracturing fluid can achieve the purpose of controlling the height of the fracture, increasing the number of bedding layers, expanding the width of the fracture, and improving the conductivity of the fracture. [0003] At present, the pump-off sand settling fracturing technology is mainly used in sandstone ...

AI Technical Summary

Problems solved by technology

[0004] For small thickness, high in-situ stress and fractured reservoirs, the success rate of conventional thin layer fracturing is low, easy to sand plugging, the success rate of construction is 50%, and the effective period of fracturing is short, within 60d

For reservoirs with poor interlayer conditions or loose reservoirs where proppant has penetrated seriously, the fracture height cannot be effectively controlled by conventional sand fracturing, and it is easy to communicate with the upper and lower aquifers or the effective sand concentration in the fractures decreases, resulting in post-fracture fractures. Intensified or ineffective flooding

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