Testing XLE For Cost Savings in the DJ Basin: A Fiber Optic Case Study
Authors: Barhaug Jessica , Bussey Jacqueline , Schaeffer Ben , Shemeta Julie , Lawrence Matthew , Tran John , Stark Price 
Published: January 2022

Abstract
Historically, Great Western Petroleum has been an operator focused on efficiency without much focus on altering completion designs. Based on the successes of Extreme Limited Entry (XLE) in other basins, a science project was constructed to test different XLE in the first zipper group of a two-zipper group pad. The goal was to find a design that would yield the same production, but with less cost. Increasing stage length provides a significant cost saving and with XLE, production should be maintained. Based on the results from zipper one, the best design could then be implemented on the same pad in the second zipper group. This allows for a direct comparison of hydraulic fracturing designs, minimizing geologic impact.
This study was comprised of a number of different datasets with the primary focus being on Distributed Acoustic Sensing (DAS) using wellbore fiber optic cable. DAS is a rapidly evolving technology with numerous advances in both function and cost over the last few years, especially in fiber optic cable deployment. An opportunity was seen to not just gather data, but to test the data quality of the latest deployment methods, specifically a pump-down dissolvable, single-use fiber optic cable. This is a cost effective and minimal footprint option for data collection. This project included three acquisition methods for the DAS: 1) a permanent fiber optic line cemented on the outside of the casing, 2) a wireline retrievable fiber optic line, and 3) a pump-down dissolvable single-use fiber, all deployed in three unique wellbores. The permanent fiber optic well was used to compare the uniformity index of different completion designs. The designs were altered based on the results from the previous stage until an optimal design was reached. This DAS acquisition also provided offset strain and microseismic in the first and second zipper groups. The wireline retrievable fiber optic cable and single-use fiber optic cable deployments provided offset strain and microseismic for the wells in the first zipper group. High level observations resulting from this project include:
The data quality associated with the dissolvable single-use fiber looked comparable in data quality to the other fiber optic deployment methods. The Uniformity Index was high for most designs, even with stages as long as 450 ft and cluster spacing as tight as 7 ft. 350’ stages with 14 clusters at 1 spf was chosen for the second zipper group wells This provided significant cost savings, along with high stage uniformity Results from the offset strain and microseismic analysis from tighter and more clusters per stage showed less interference than what was seen with our legacy design stages RTA shows that compared to a pad with similar well spacing, the production is better with the new hydraulic fracture design
Having a case study with various fiber optic deployments is rare. At the time of this deployment, this was the first pump down dissolvable single-use fiber optic line in North America. This paper will show the efficacy of this fiber optic deployment compared to its peers. It also will look at conventional and XLE designs and the well-to-well interference differences. Finally, being able to compare production results to an offset pad with the same well spacing provides a unique opportunity to validate the effect of a new hydraulic fracture design.