The infinite conductivity theory to enhance production was introduced to the industry around 1971. Exploration from the 1970s to the 1990s focused on high permeability formations. The unconventional reservoirs and tight formations were left behind until new technology could enable hydrocarbons to be produced in economical manner. Operators seek methods to both increase initial production and slow the decline rates. This paper describes the infinite conductivity technique to help to enhance production in unconventional reservoirs and tight formations.
The advanced pillar fracturing technology was evaluated as an infinite conductivity technique using binding agents to help generate stabilized proppant pillars to create voids and conduits inside the induced fractures during fracture stimulation treatments. The pillars remain stable at reservoir pressure and temperature to help to prevent excessive fracture closure during drawdown. The methodology uses specific surface equipment designed to establish pulsing of slurry and clean fluid segments during proppant placement. This methodology is combined with liquid resin technology to help to prevent proppant and fines migration, as well as reduce proppant embedment that would allow blockage of the conduit spaces. Consequently, the new technology reduces the necessary proppant volume pumped into the formation, thereby reducing the potential of proppant screenout.
Mechanical stress on the packed fractures is significantly greater during production when drawdown pressures are maximized and reservoir pressures begin to decline. These two pressures can lead to greater stresses on the proppant after closure. High closure stress also applies pressure to the proppant during production; consequently, the proppant has an increased tendency to crush. Proppant diagenesis is possible and can consequently contribute to reductions in conductivity. However, the application of liquid modified resin creates a film on the proppant surface, resulting in significant reductions in proppant reaction with the formation rock and fluid. This technique reduces diagenesis and helps to control fines generated from crushing that could plug the proppant pack and reduce conductivity. Modified liquid resin also increases pillar strength by creating a film on proppant grains. The application of different shear stresses enhances and stabilizes the strength of the pillar and keeps the newly created conduits open to flow. This paper presents a case history that shows that the production from a well stimulated without modified liquid resin declines significantly more than another well treated with resin-coated proppant. This paper presents a novel infinite conductivity technique that uses a pulsed proppant fracturing process to provide enhanced and sustained production over conventional treatments. The proppant pulsing process helps to create proppant pillars with open flow paths that are highly conductive and can enable almost infinite conductivity.