CO2-sensitive fracturing and displacement fluid and method of making the same and method for fracturing and displacement of tight oil reservoir

US10584276B2 · kind B2 · utility

Assignees

• CHINA UNIVERSITY OF PETROLEUM (EAST CHINA) · CN
• CHINA UNIVERSITY OF GEOSCIENCES (BEIJING) · CN
• SCIENCE AND TECHNOLOGY RESEARCH INSTITUTE LTD., PETRO CHINA · CN

Inventors

• Caili Dai · Qingdao, CN
• Mingwei Gao · Qingdao, CN
• Mingwei Zhao · Qingdao, CN
• Qing You · Beijing, CN
• Guang Zhao · Qingdao, CN
• Yining Wu · Qingdao, CN
• Yongpeng Sun · Qingdao, CN
• Lin Li · Shoreview, US
• Yifei Liu · Beijing, CN
• He Liu · Beijing, CN
• Xin Wang · Qingdao, CN
• Baoshan Guan · Beijing, CN

Key dates

• Filing date: Apr 23, 2019
• Grant date: Mar 10, 2020
• Expiry date: Apr 23, 2039

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/54
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A CO2-sensitive fracturing and displacement fluid contains a surfactant, an auxiliary agent, water, and CO2, wherein CO2 is liquid and/or supercritical CO2. The CO2-sensitive fracturing and displacement fluid provided by the invention does not flow back after completion of fracturing construction, and the gel breaking fluid displacement is carried out after soak for a period of time to improve the tight oil recovery ratio. The CO2-sensitive fracturing and displacement fluid exerts the “one-agent multi-purpose” function of sand carrying, CO2 energization and oil displacement, surfactant imbibition and oil discharge of a fracturing-displacement system in different development and production stages, and achieves the dual goals of expanding the utilization degree of tight oil and improving the displacement efficiency of the tight oil, which can effectively reduce costs and achieve the goal of unified, highly efficient and green development of oil and gas fields.