Predicting the Performance of Undeveloped Multi-Fractured Marcellus Gas Wells Using an Analytical Flow-Cell Model (FCM)

David Waters,Ruud Weijermars

doi:10.3390/en14061734

Abstract

The objective of the present study is to predict how changes in the fracture treatment design parameters will affect the production performance of new gas wells in a target zone of the Marcellus shale. A recently developed analytical flow-cell model can estimate future production for new wells with different completion designs. The flow-cell model predictions were benchmarked using historic data of 11 wells and 6 different completion designs. First, a type well was generated and used with the flow-cell model to predict the performance of the later infill wells—with variable completion designs—based off the performance of earlier wells. The flow-cell model takes into account known hyperbolic forecast parameters (qi, Di, and b-factor) and fracture parameters (height, half-length, and spacing) of a type well. Next, the flow-cell model generates the hyperbolic decline parameters for an offset well based on the selected changes in the fracture treatment design parameters. Using a numerical simulator, the flow-cell model was verified as an accurate modeling technique for forecasting the production performance of horizontal, multi-fractured, gas wells.

Highlights

This study uses detailed well data from a lease region in the Marcellus shale to benchmark history matching results of a recently developed analytical flow-cell model [1,2,3] and independent results from a numerical reservoir simulator (CMG-IMEX)
The naturally fractured model had a 25% increase in estimated ultimate recovery (EUR)
The numerical simulator was successfully matched to the historical performance of one of the wells

Summary

Introduction

This study uses detailed well data from a lease region in the Marcellus shale to benchmark history matching results of a recently developed analytical flow-cell model [1,2,3] and independent results from a numerical reservoir simulator (CMG-IMEX). The lease region in the Marcellus shale has 11 active gas production wells in a key part of the Middle Devonian organic-rich formation with ultra-low matrix permeability [4]. Gas production from the Marcellus shale increased rapidly since 2008 when horizontal drilling and multistage hydraulic fracturing allowed economic recovery by increasing the reservoir contact and creating increased permeability [5]. The Marcellus shale exploitation has continued to grow and now is the biggest producer of natural gas within the United States at ~23 Bcf/day out of the total production of ~73 Bcf/day [6]. Throughout the years, operations within the Marcellus have changed significantly, driven by a variety of factors such as volatile commodity prices, varying well costs, and continual technology advancements.

Objectives

Findings

Discussion

Conclusion