Fracture Modeling Using a Constructed Discrete Fracture Network From Seismic Data

Topics: Hydraulic fracturing Petrophysics/geophysics
Fig. 1—(a) Map of the two-well pad, with wells 600 ft apart with seismic-built DFN calibrated with offset borehole-image logs. (b) Map of microseismic data with DFN overlain in background.

The objective of this study is to validate the concept of using a seismically derived discrete fracture network (DFN) calibrated with borehole measurements, for complex-hydraulic-fracture modeling. This study was applied successfully on a two‑well horizontal pad in the Avalon Shale located in the Delaware Basin, New Mexico. The work flow presented in this paper shows the successful application of seismic data in creating DFNs required to model hydraulic fractures in unconventional reservoirs.

Introduction

In the past, hydraulic-fracture modeling was limited to planar models for conventional reservoirs, with the absence of natural fractures. In unconventional reservoirs, planar models are highly limited in properly simulating complex fracture geometries. In recent years, a state-of-the-art complex- fracture-network model, also known as an unconventional fracture model (UFM), was developed. The model simulates the fracture propagation, rock deformation, and fluid flow in the complex fracture network created during a treatment. A key difference between the UFM and the conventional planar-fracture model is the ability to simulate the interaction of hydraulic fractures with pre-existing natural fractures.

In shale plays, conventional DFN models are built out of 1D fracture-dip interpretation from a borehole-image log or from core in the same or a nearby well. However, because the hydraulic fractures created during a stimulation treatment usually extend hundreds of feet away from the wellbore, it is important to characterize and understand the natural fractures away from the wellbore. Therefore, a more- accurate DFN model than the simple conventional model is crucial in unconventional plays for optimizing well spacing and stimulation design to ultimately achieve maximum effective drainage while maximizing returns.

In this study, the authors use an established work flow for extracting seismic-scale fracture networks and extending their population properties to model corresponding subseismic fractures that are critical to understanding and calibrating complex-hydraulic-fracture geometry created during stimulation.

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 179130, “Calibrated Complex Fracture Modeling Using a Constructed Discrete Fracture Network From Seismic Data in the Avalon Shale, New Mexico,” by Foluke Ajisafe, Manoj Thachaparambil, Donald Lee, Ben Flack, Kim Hemsley, Efe Ejofodomi, and Christopher Taylor, Schlumberger, prepared for the 2016 SPE Hydraulic Fracturing Technology Conference, The Woodlands, Texas, USA, 9–11 February. The paper has not been peer reviewed.
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Fracture Modeling Using a Constructed Discrete Fracture Network From Seismic Data

01 March 2017

Volume: 69 | Issue: 3