Surveillance Study on Hydraulic Fracture Characteristics in Tight Formation

Production on high reserves reservoirs will uplift the productivity index; hence increase the economic feasibility of a project. Nowadays, low permeability reservoir is possible to be produced. Production for tight reservoirs require appropriate stimulation jobs to increase the permeability. In this study, hydraulic fracturing is chosen as the stimulation method. With current depletion in conventional resources, many oil and gas players have found hydrocarbons in tight reservoirs as the alternatives. The emergence of hydraulic fracturing has made the United States become the world’s largest natural gas producer in 2009.
About the study of hydraulic fracturing, it is important to understand how this stimulation method will affect the productivity index of the well. Researchers have to study the post-fracture behaviour, such as the fracture conductivity in the reservoirs and the fracture half-length and width. To calculate the post-fracture results, productivity improvement factor (PIF) is used as the indicator.
In hydraulic fracturing, a propping agent, usually sand particles, is used as the medium to contain the stresses acting on the fractures. Other than sand, water and chemical additives complete the composition of hydraulic fracturing fluid. In this study, the effect of fracture conductivity, half-length and width on production rate are investigated. Then, the post-fracture production rate will be compared with the initial production rate by calculating the PIF.
In conclusion, this study provides better understanding to the engineers on the minimum requirements of fracture conductivity and fracture half-length that the hydraulic fracturing process must achieve. Also, the study of hydraulic fracturing characteristics in tight formation will give benefits to the surveillance team, which they can predict the outcome and efficiency of the stimulation job.