Drilling fluid additive composition suitable for coal-bed gas wells, and water-based drilling fluid and use thereof

US9902890B1 · kind B1 · utility

Assignee

• China University of Petroleum—Beijing · CN

Inventors

• Guancheng Jiang · Beijing, CN
• Yinbo He · Beijing, CN
• Chong Liu · Longbeilingcun, CN
• Qingying Ge · Beijing, CN
• Lili Yang · Pasadena, US
• Yong Wang · Beijing, CN
• Yongqing Zhang · Nanjing, CN
• Zhaohui Wang · Walnut Creek, US
• Lin Cheng · Qingdao, CN
• Jingdong Hu · Beijing, CN
• Deli Gao · Beijing, CN
• Haifang Sun · Beijing, CN
• Xi Wang · Beijing, CN

Key dates

• Filing date: Jun 28, 2017
• Grant date: Feb 27, 2018
• Expiry date: Jun 28, 2037

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E21B43/006
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to the well drilling field in petroleum industry, in particular to a drilling fluid additive composition suitable for coal-bed gas wells, and a water-based drilling fluid and use of the water-based drilling fluid. The drilling fluid additive composition suitable for coal-bed gas wells, comprising a tackifying and shear improver, a capsulating agent, a filtrate reducer, and an amphiphobic wettability reversal agent, wherein, the tackifying and shear improver is a copolymer comprising structural units represented by formula (1), structural units represented by formula (2), and structural units represented by formula (3); the capsulating agent is a comb-like polysaccharide compound; the filtrate reducer is nanocrystalline cellulose, and the amphiphobic wettability reversal agent is a dual-cation fluorocarbon surfactant. The composition provided in the present invention can be used as an additive in a solid-free brine drilling fluid, so that the brine drilling fluid obtains advantages of a high penetration rate and a low residue rate.