Fracturing method

Abstract

The invention provides a fracturing method. The fracturing method comprises the following steps of: 1, opening a main crack by using water-based fracturing fluid, and sealing and filling a gap throat near the crack; 2, using the carbon dioxide fracturing fluid for communicating with micro-fractures in the reservoir to form a fracture network; and 3, using carbon dioxide fracturing fluid for carrying a proppant to support the crack network formed in the step 2. The fracturing method combines the water-based fracturing technology and the liquid carbon dioxide fracturing technology, a main crack is firstly made, then the carbon dioxide fracturing fluid is used for forming the crack network, and the crack network is formed. A slug sand adding mode is used for supporting the crack network, so that a longitudinal and transverse'net-shaped crack 'system taking the main crack as a trunk is formed in the construction mode, and the well control area is enlarged.

Description

Technical field [0001] The present invention relates to the field of petroleum engineering development, particularly relates to a water-based fracturing fluid - carbon dioxide fracturing anhydrous energization complex. Background technique [0002] In recent years, carbon dioxide has been widely used in fracturing oil and gas, in particular, the transformation process is applied to the reservoir of unconventional sources such as shale oil reservoirs, tight oil reservoir and the like. Carbon dioxide fracturing uses liquid or supercritical carbon dioxide into the formation, using the characteristics of complex cracks by carbon dioxide to achieve higher degrees of reservoirs, and achieve multiple energy of the reservoir, and the crude oil. As Lu Yucheng (2013), the supercritical carbon dioxide fracture method and system (CN201310220539.3) ", which proposed a supercritical carbon dioxide fracturing system for developing shale gas, including storage tanks, booster pumps. Equivalence, ...

AI Technical Summary

Problems solved by technology

The fracturing method is to provide a water-based fracturing fluid-carbon dioxide anhydrous energized composite fracturing method, which combines the two unconventional fracturing technologies of water-based fracturing technology and liquid carbon dioxide fracturing technology, and chooses in different Different fracturing fluid systems are injected in stages, and the special properties of different fracturing fluids are rationally used to achieve the effect of creating a fracture network, increasing the oil and gas migration capacity of fractures, and forming a vertical and horizontal "network fracture" with main fractures as the backbone The system expands the well control area. At the same time, after the fracturing fluid breaks the gel, a large amount of gas dissolves in the crude oil, which increases the energy of the formation and improves the seepage characteristics of the reservoir. It is especially suitable for low-permeability, tight, and strong water-sensitive reservoirs. Increased productivity after single well fracturing, and solved the problem of poor fracturing effects in low-permeability and tight reservoirs

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