The Research and Application of Ultra High Temperature Fracturing Technology for Glutenite Formations

Abstract

Abstract The temperature of some glutenite reservoirs of Shengli oil field located in the east of China reaches up to 180°C, and it would exceed 190°C in the subsequent exploring reservoirs, even close to 200°C. Nevertheless, neither the fracturing fluid system nor the down hole instruments can satisfy the fracturing technology demands at such high temperature, which restricts the effective exploration and development of high temperature deep reservoirs in Shengli oil field. Therefore, it's necessary to launch the research into ultra high temperature fracturing technology of glutenite reservoir, and to carry out field application. Through additive development, performance optimization and systematic performance evaluation, this research firstly developed the ultra high temperature fracturing fluid system enduring 200°C, which could maintain the viscosity of 100–110 mPa.s when it was continuously sheared for 120min under the conditions of 198°C and 170s−1, and laid the foundation for ultra high temperature fracturing. Based on the analysis of the configuration of high temperature and high pressure packer, the self-sealing and compression packing elements were designed. And then the ZY541 packer enduring the pressure of 70MPa and the temperature of 180°C was firstly invented, which provided the apparatus guarantee. The research results were applied to well ZG63, and the construction continued for 120 minutes at the highest construction temperature of 184.6°C in China, which created a new fracturing record, validated the reliability of ultra high temperature fracturing fluid and down hole instruments, and realized the important breakthrough of ultra high temperature fracturing technology as well. This research solved the key technology difficulties of deep and ultra high temperature fracturing in China, upgraded the level of fracturing technologies in this type of reservoirs, and effectively promoted the exploration and development of ultra high temperature reservoirs in China.