Unconventional gas resources refer to natural gas reserves in the tight sands or carbonates, shales, and in coals. There are many factors that differentiate these unconventional reservoirs from the conventional reservoirs. Unlike conventional reservoirs, unconventional reservoirs have large areal extent, not easily accessible, have significantly high development cost, and are characterised by extremely low flow capacity and high in-situ stress conditions. To produce from vast geographical areas requires drilling significantly large number of wells to achieve a large reservoir contact.
The completion assembly needs to be robust to ascertain that wells can be fractured even with high fracture gradients. The mechanisms to produce from such unconventional sources are very difficult and challenging—extensive reservoir engineering and management skills are required for successful development and exploitation of hydrocarbons. The application of novel technologies and methodologies in exploration, drilling, completion, fracturing, and production is required to enhance production and to make these resources commercial.
The most significant part in the development of unconventional gas is the successful implementation of hydraulic fracturing technology. However, the prerequisites to have an optimum fracture treatment cover a wide range of factors—proper selection of well location, drilling azimuth, landing point, reservoir contact, completion strategy, use of best fluids and proppant types, and critical design of fracture treatment with regards to fracture stages, pump schedule, volume, and injection rate.
The Unconventional Gas Fracturing workshop will focus and emphasise on the following critical factors: