This paper presents the results of integrating microseismic fracture mapping with numerical production modeling of fracture networks in the Barnett shale. Microseismic fracture mapping has shown that hydraulic fracture treatments create large-scale fracture networks in the Barnett shale. In this paper an approach is presented, where the fracture network measured with microseismic mapping is approximated with a numerical production simulator that discretely models the network structure in both vertical and horizontal wells.
The work includes a production history match of a vertical Barnett shale well, where the microseismic mapping results were directly used to approximate a fracture network in the reservoir simulator, resulting in an estimate of effective fracture network length, average fracture conductivity and effective drainage area. In addition, a parametric study for horizontal wells is presented to show how fracture network size and density, fracture conductivity, matrix permeability and gaps in the network affect well productivity. Simulations on the effect of fracture face damage along the network, the effect of non-Darcy flow in the network, and tapered fracture network conductivity that decreases away from the well are also included. The numerical model was also used to simulate how a pressure buildup test would appear based on given fracture network properties, which could be a useful diagnostic to evaluate the effectiveness of the fracture network.
The results of this work illustrate how different fracture network characteristics impact well performance, which is critical for improving future horizontal well completion and fracturing strategies in the Barnett shale. This could include optimizing the number of fracture stages along the lateral, length of the lateral, treatment sizes, and perforation strategies as well as enhancing fracture network conductivity and the effectiveness of re-fracture treatments. The work also shows how microseismic mapping results can be integrated with production modeling, thereby providing a tool for more realistic infill drilling and well placement studies in the Barnett shale or similar types of reservoirs.
Author(s): Pinnacle Technologies; M.J. Mayerhofer, E.P. Lolon StrataGen Engineering, J.E. Youngblood and J.R. Heinze; Devon Energy Corp.
Paper Number: SPE 102103