Evaluation of Reservoir Quality and Forecasted Production Variability along a Multi-Fractured Horizontal Well. Part 2: Selected Stage Forecasting

Christopher R Clarkson,Daniela Becerra,Zhenzihao Zhang,Amin Ghanizadeh,Farshad Tabasinejad

doi:10.3390/en14196007

Abstract

The current practice for multi-fractured horizontal well development in low-permeability reservoirs is to complete the full length of the well with evenly spaced fracture stages. Given methods to evaluate along-well variability in reservoir quality and to predict stage-by-stage performance, it may be possible to reduce the number of stages completed in a well without a significant sacrifice in well performance. Provision and demonstration of these methods is the goal of the current two-part study. In Part 1 of this study, reservoir and completion quality were evaluated along the length of a horizontal well in the Montney Formation in western Canada. In the current (Part 2) study, the along-well reservoir property estimates are first used to forecast per-stage production variability, and then used to evaluate production performance of the well when fewer stages are completed in higher quality reservoir. A rigorous and fast semi-analytical model was used for forecasting, with constraints on fracture geometry obtained from numerical model history matching of the studied Montney well flowback data. It is concluded that a significant reduction in the number of stages from 50 (what was implemented) to less than 40 could have yielded most of the oil production obtained over the forecast period.

Highlights

Multi-fractured horizontal wells (MFHWs) are the most common technology used for economic development of low- and ultra-low (“unconventional”) permeability oil and gas reservoirs
Several of the modeling steps outlined in the Introduction section are illustrated using the Montney MFHW analyzed in the Part 1 paper [22]
The goal of this two-part study is to demonstrate that rigorous methods to evaluate along-well variability in two-part reservoir/completion (Part 1), combined with a simpleThe goal of this study is quality to demonstrate that rigorous methods to evaluate yet-rigorous method for predicting stage-by-stage performance that accounts for this varalong-well variability in reservoir/completion quality (Part 1), combined with a simple-yetiability in reservoir quality (Part 2), may be used to reduce the number of stages completed rigorous predicting stage-by-stage performance that in a well method without a significant sacrifice in accounts well perfor-for this variability inmance

Summary

Introduction

Multi-fractured horizontal wells (MFHWs) are the most common technology used for economic development of low- and ultra-low (“unconventional”) permeability oil and gas reservoirs This technology has enabled production from reservoirs that have been traditionally viewed as “non-pay”, with permeabilities in the 10 s to 100 s of nanodarcy range. MFHWs are commonly drilled from the same pad, often targeting more than one (vertical) reservoir interval in an unconventional play Another common practice is to place fracturing stages uniformly (or geometrically) along a well; multiple perforation clusters, used as initiation points for hydraulic fractures, are often used, with the cluster spacing typically constant within a fracture stage. A number of approaches have been used to generate forecasts for MFHWs, which can be classified as empirical [3,4,5,6], analytical [7,8,9,10,11], semi-analytical [12], or hybrid [13,14] methods

Results

Discussion

Conclusion