As exploration goes deeper, most conventional methods have to be modified or completely re-engineered to hold up to these extreme conditions. Fracturing fluids are no exception to these changes. Fluids have evolved rapidly to adjust to an ever changing market. The trick is to make them as easy as possible to deliver on location. There have been several attempts at developing new high temperature fluids that will give good stability and deliver the fracture properties desired. Most of these to date require special handling and have operational difficulties.
A new high temperature synthetic low-pH crosslinked fluid system has been developed to avoid these pitfalls. The system employs a synthetic co-polymer in an environmentally compliant oil-based emulsion that hydrates very rapidly with excellent fluid rheology properties. Proppant pack regain conductivity using encapsulated oxidizers has also shown very good cleanup at these temperatures. The system uses exceedingly low polymer concentrations (18 to 40 pptg) compared to others (60 to 100 pptg) at temperatures from 350 to over 450°F. The fluid can also be energized with nitrogen or carbon dioxide or foamed if needed. Operationally, fracturing with this fluid can be performed with conventional equipment without any modifications. The paper will present the chemistry and technology of this new fluid including rheology and cleanup data.
This new technology has the potential to change the manner in which ultrahigh-temperature wells are completed.