WorldOil

Selection of fracturing fluid for stimulating tight gas reservoirs

Essentially all producing wells drilled in tight gas sands and shales are stimulated using hydraulic fracture treatments. The development of optimal fracturing procedures, therefore, has a large impact on the long-term economic viability of the wells. The industry has been working on stimulation technology for more than 50 years, yet practices in use may not always be optimal. Using information from the petroleum engineering literature, numerical and analytical simulators, surveys from fracturing experts and statistical analysis of production data, a flowchart was developed to guide selection of the appropriate facture fluid in most gas shale and tight gas reservoirs. Various parameters are considered, such as the type of formation, the presence of natural fractures and reservoir properties. HYDRAULIC FRACTURE STIMULATION Hydraulic fracturing plays a key role in producing unconventional gas resources. In the first stage, a small quantity of fluid, known as “pre-pad,” is pumped down the well to fill it...