Abstract
A finite-difference hydraulic fracturing simulator has been used to determine fracture growth and geometry in the Khuff and Pre-Khuff formations of the Ghawar gas reservoir. A layered reservoir system approach has been used where each reservoir is divided into several layers based on the geomechanical and flow properties and reservoir lithology. Single and multiple perforated interval scenarios have been studied to compute fracture growth and proppant transport. The effects of geomechanical properties such as in-situ stress, Young's modulus, closure pressure, and rock embedment strength on fracture dimensions have been investigated. Effects of fluid properties such as, injected volume, percentage of pad fluid, leakoff coefficient, etc. have also been investigated.
Several examples with actual field data have been presented in the paper for reservoirs with multiple producing zones in which fracture is initiated in one or many intervals simultaneously so that the impact of perforations, mechanical properties, and flow characteristics could be identified and calculated. These examples illustrate the importance of knowing the formation properties correctly and choosing the most appropriate treatment size and perforation strategy to effectively fracture a reservoir.
A sensitivity study on incremental gas production is also presented in the paper. This study illustrates production increase as functions of reservoir and fracture properties and provides a guideline to optimally choose fracture length and conductivity for an economic and efficient fracture treatment.
