Keywords: well damage, hydraulic fracture, tight gas reservoirs, type curve, gel damage identification, well productivity, gas recovery, oil and gas industry, damage factors, tight gas wells, petroleum engineering
Development and application of a type curve for gel damage identification in tight gas wells
Fracture treatments have been proved to be the effective and efficient method in stimulating tight–gas reservoirs. The key is to create a long, highly conductive fracture to increase the well productivity and ultimate gas recovery. Since 1960s, fracture damage mechanisms have been investigated by petroleum engineers, researchers, and field personnel to better understand what caused lower fracture conductivity and shorter fracture lengths. Based on our critical and comprehensive literature review, we found that more than 20 damage factors have been understood and quantified. However, there is still no method available for identification of gel damage in the field. Based on numerical simulation results (Wang et al., 2008), we have developed a new type curve for identification of gel damage in tight gas wells. The type curve has been applied to six wells in the Cotton Valley formation of central Texas. The severity of gel damage in each well was ranked in the order of no damage, slight damage, medium damage, and severe damage. This type curve provides a new tool for practicing petroleum engineers to identify fracture damages in tight gas wells worldwide.