Expanding Interpretation of Interwell Connectivity and Reservoir Complexity through Pressure Hit Analysis and Microseismic Integration

Abstract

This paper presents a multi-disciplinary workflow for analyzing interwell hydraulic fracturing pressure interactions on multi-well horizontal pads in unconventional reservoirs. Over twenty wells in multiple fields with varied spacing across multiple landed zones are evaluated. The workflow provides a method for determining the degree of connectivity between the wells to assess the extent and complexity of the stimulated network. The analysis method provides a cost efficient, timely means of understanding the stimulated network in order to impact decisions regarding well spacing, injection rate, perforation design and frac order.Prescriptive completions programs enable observation of pressure interactions between wells during multi-stage hydraulic fracturing. Wellhead pressures are continuously recorded during all completion and flowback operations. In the observation pads studied, wells experience varying degrees of pressure communication across the fracture network. Pressure hits are grouped by according to identifying characteristics and correlated to microseismic data where available.Characterization of the stimulation network gained from analysis of pressure interactions closely aligns with available high resolution microseismic data. Networks are shown to have significant vertical and lateral growth establishing a highly complex network. Additional insights on the degree of connectivity and the definition of effective fracture network are gained. Results are fundamental to understanding well spacing and zonal placement.

Physical Models for Inter-Well Interference in Shale Reservoirs: Relative Impacts of Fracture Hits and Matrix Permeability

“…In addition, pressure testing on pad wells is often utilized to identify the well interference (Portis et al 2013;Sardinha et al 2014;Sani et al 2015;Scott et al 2015). Also, microseismic monitoring can be combined with the pressure test to improve understanding the well interference (Grossi et al 2015;Lehmann et al 2016). During the pressure test, all wells are first shut in to build up pressure.…”

Interwell Hydraulic Fracture Interaction Between Multistage Stimulated Wells and a Multi Zone Slant Open Hole Observation Well Placed in the Canadian Horn River Basin

“…This combined knowledge is applied by the Nexen design team to improve understanding of wellbore placement and provide team geoscientists and engineers cost-effective and quick turnaround tools for improving stimulation efficiency of horizontal multi-well pad developments in variable geological environments (Sardinha, 2014;Lehmann, 2016). This paper presents the novel application of these technologies to evaluate a deviated slant openhole observation wellbore in the Horn River Basin.…”

“…Distinct pressure responses resulting from offsetting stimulations can be compared based on intensity using methods modified from previously presented analyses (Sardinha, 2014;Lehmann, 2016). The pressure increase per unit time in the observation wellbore, as a result of offsetting stimulations, forms the basis of this analysis.…”