The study aims to provide actionable insights for operators and stakeholders on how to manage well spacing, sequencing, and landing zone true vertical depth (TVD) to increase the production potential of unconventional oil and gas wells. The objectives are to evaluate the impact of well spacing, investigate different well sequencing strategies, analyze the impact of TVD, and provide actionable insights for operators and stakeholders on how to optimize production potential.
This study examined the performance of wells that started production from 2015 onwards in eleven unconventional plays across North America, namely Bakken, Barnett, Delaware, Duvernay, Eagle Ford, Haynesville, Marcellus, Midland, Montney, Scoop|Stack, and Utica. To evaluate performance, the study established four key performance indicators (KPIs) based on production data, normalized for the first 3 and 12 months using stimulated lateral length (SLL) alone or SLL and total proppant (SLLandTP). The analysis utilizing statistical and machine learning techniques involves evaluating the impact of well spacing, sequencing, and landing zone TVD on four KPIs, with comparisons made between individual plays and a comprehensive global assessment of all the plays.
For optimal short-term (3 months) performance, wells with small horizontal spacing and large vertical spacing performed best, while wells with intermediate horizontal spacing, large vertical spacing, and proppants performed best for optimal medium-term (12 months) performance. Parent wells were found to be the most productive, while standalone wells were the least productive. Co-completed wells performed better over child wells when proppants were used in both. Well sequencing was the least important for predicting production in most cases, while TVD was identified as the most important feature. Proppants may not be effective at high TVD levels. Instead, high TVD and consequent high pore pressure may play a critical role in determining productivity, which could even surpass the significance of formation evaluation factors.
Limited research exists to show play-level trends in well performance as a function of well spacing, sequencing and landing zone TVD. Unlike prior studies, which rely on numerical simulations with simplifications/assumptions about the reservoir and wells, this study uses real-world field data to perform a comprehensive and realistic analysis of these factors. The study’s findings propose potential optimization strategies to improve well performance through well spacing, sequencing, and landing zone TVD.
