Question

Explain “Why foam fracturing is more popular in shale gas production systems”?.
Also, mention three examples where foam fracturing is done?
Minimum 500 words

Answer 1

Foam fracturing is highly popular due to low viscosity which is able to the ends of the fracture. It also has high proppant carrying capacity that reduces water consumption and chemical uses and facilitates quick and easy fluid flow back. Foam fracturing techniques reduces overall pumping and operating cost due to its low viscosity. The viscosity and density of foam-based fluids have 250 kg/ m3 and 0.15 Pa.s. which is nearly 1/4 the of the density and 1/3 rd of the viscosity of fracturing fluid. Another advantage of foam fracturing is it's reduced water usage, reduced wastewater generation, reduce formation damage, higher proppant capacity and it's recyclable or reusability. Foam fracturing techniques are also highly environmentally friendly and it minimises the overall environmental damage. Various foam generating materials like nitrogen, CO2 with water, acid or alcohol are effectively utilized. Slick water fracturing created micro-fractures that enhance shale gas production.

Foam fracturing is tried at various places like Devonian shale in Youngstown USA, Jackson county, lower iron shale fairway the USA and Cenomanian formation in western Siberia.

The examples of foam fracturing are water-based foam fracturing (water + foaming surfactant + N2 or CO2), acid-based foam fracturing (acid + foaming surfactant + N2 has) and alcohol based foam fracturing (methanol + foaming surfactant + N2 ). All these methods are used in low pressure formulations, low pressure water sensitive formulations and low pressure formulation with water blocking case respectively.