Analysis on parameters involved in 2-D fracture geometry design

Abstract

During past decades, the depletion of oil and gas reservoirs and increasing of the hydrocarbon price, major companies in oil and gas industry endeavor to enhance the recovery of hydrocarbon from the present reservoirs as well as marginal reservoirs. One of the most successful ways to improve oil and gas recovery is to perform Hydraulic Fracturing technique. Modelling of fracture geometry (width, length, and height) is an aspect, specifically in the interest of hydraulic fracturing as a stimulation technique. To have an accurate and optimum fracture design, it is important to evaluate the influence of design parameters on the dimension of an induced fracture in fracture design models. The classical models for fracture geometry in two dimension are the PKN (Perkins–Kern–Nordgren) and KGD (Kristianovitch–Geertsma– Daneshy) models. Effect of each parameter on the fracture geometry is important in order to know which one has positive or negative effect. A sensitivity analysis will be performed in order to find out the impact of each parameter on the fracture geometry by employing Microsoft Excel® 2013. The input data have been extracted from previous successful treatment that have been done in a Malaysian gas condensate reservoir named Angsi. Parameters that may affect the fracture geometry and going to be assessed are related to the mechanical rock characteristics and fracturing fluid specification. They are Poisson’s ratio, Young’s Modulus, fluid pumping rate, fluid viscosity and fracture height. Based on KGD model, it is observed that value of fracture width will improve by increasing the values of fracturing fluid pumping rate, Poisson’s ratio and Young’s Modulus and decreasing the values of fracturing fluid viscosity and fracture height. In terms of fracture length due to KGD model, same trend is present for pumping rate and fracture height, however, a reverse trend obtained for variations of Poisson’s ratio, Young’s Modulus and fluid viscosity. A similar analysis was performed based on PKN model. Furthermore, a comparative analysis has been done to compare these two design models in order to find the sensitivity of the design parameters on the fracture geometry.