Southwest Petroleum University

Donghe Yu

Pingli Liu

Zhifeng Luo

Juan Du

Liqiang Zhao

Nianyin Li

Kun Xu

Guangyan Du

Hang Che

Guohua Liu

Yuxin Pei

Yong Yang

Bingxiao Liu

The present invention discloses a phase change fracturing fluid system for phase change fracturing, including the following components in percentage by weight: 10%-40% of supramolecular construction unit, 0-40% of supramolecular function unit, 0.5%-2% of surfactant, 0-5% of inorganic salt, 0.5%-2% of oxidizing agent, 0-2% of cosolvent and the remaining of solvent. The supramolecular construction unit is melamine, triallyl isocyanurate, or a mixture thereof. The supramolecular function unit is vinyl acetate, acrylonitrile, or a mixture thereof. The solvent is methylbenzene, ethylbenzene, o-xylene, m-xylene or p-xylene. In the fracturing construction process, a conventional fracturing fluid is used for fracturing a formation first; the phase change fracturing fluid is then injected into the formation, or the phase change fracturing fluid and other fluids which cannot be subjected to phase change are injected into the formation together.

Phase change fracturing fluid system for phase change fracturing

A phase-change hydraulic fracturing process, including the following steps: (1) injecting clean water or conventional fracturing fluid to a formation, so that the formation fractures; (2) placing non-phase-change liquid and phase-change liquid in different liquid mixing tanks and injecting into a shaft at the same time, an injection volume ratio of the non-phase-change liquid to the phase-change liquid is (0-0.7):(0.3-1); (3) injecting a displacement fluid into the shaft, so that the non-phase-change liquid and the phase-change liquid in the shaft completely enter a reservoir; (4) performing well shut-in and pressure-out for 30-200 min, so that solid-phase matters generated by the phase-change liquid are laid in the fracture; and (5) relieving pressure to finish the construction.

Phase-change hydraulic fracturing process

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Cangzhou, China

Donghe Yu