The industry continues to face a challenge understanding and optimizing completion strategies to minimize the impact of infill development on existing wells and achieve larger Stimulated Reservoir Volume (SRV) on infill wells. This paper presents a cost-effective technique for evaluating parent-child interaction using poroelastic pressure responses on the parent wells. The method was employed on a four-well pad in the Eagle Ford to understand diversion effectiveness and the extent of offset depletion. The case study comprised the analysis of pressure data sets, covering wellhead pressure data from the nearby parent wells. The method quantifies and interprets pressure signal magnitude and its transient behavior for each completed stage. The well offsetting the parent well was completed using two different completion designs. One half of the lateral was completed without employing diversion, while the other half employed a specific diversion strategy. The primary goal of the case study was to demarcate the areal extent and degree of depletion around the existing wells and determine the effectiveness of using diversion in inhibiting growth towards parent wells. The analysis determined fluid and fracture pathways, mainly seen driven by formation stresses, depletion, and completion design in each stage. The case study compared the effects of employing diversion vs. not employing diversion, using the magnitude of pressure responses felt by the parent well. The initiation points of the pressure signals, as felt by the offset wells on each side quantified how quickly and in which direction the newly treated fractures were growing. The pressure responses from multiple parent wells were correlated to understand the areal extent of depletion around each offset producer. This ultimately promotes understanding the difference in pre and post production of the wells and optimizes infill completions for future development. Cross well analysis using poroelastic pressure responses is easy to implement and very cost-effective. The proposed method provides a workflow to analyze offset pressure data in a consistent and reproducible manner. This method affords the industry a better understanding of parent well damage and mitigation of child well productivity loss.

This paper discusses a STACK (Sooner Trend Anadarko Basin Canadian and Kingfisher Counties) case study that determined the effectiveness of different diversion techniques, including pods, sand ramps with sand slugs, rate cycling, and utilization of the completions order to control fracture growth. A secondary goal of this study was to evaluate the suitability of pressure-based fracture maps and oil and water phase tracers in monitoring diverter effectiveness. Effectiveness of a given diverter technique and diverter drop was evaluated using the two techniques on a 3-well pad. The three wells were completed using a combination of: 4 pods per treatment interval6 pods per treatment interval8 pods per treatment intervalhigh-volume proppant loading per treatment interval The effectiveness of the diverter drop was evaluated using each of the diagnostic techniques listed above. The pressure-based fracture analysis uses the pressure response recorded in an isolated stage in the monitor well to compute fracture geometry and the rate of growth of the fracture dimensions. The effectiveness of a given diverter drop is classified into one of four possible categories: stop dominant fracture growth, impede dominant fracture growth, no impact on growth of dominant fracture and accelerate the growth of dominant farcture. These results were then compared with the analysis from oil and water phase tracers and treatment pressure analysis. Successful (effective) diversion was observed on 82 % of the stages with pods compared to 64% successful diversion where sand ramps were used. In addition, stages using 8 pods for diversion had a 15% reduction in average fracture half-length compared to stages using 4 pods. Fracture height was better controlled through the order of completions of the stages between 3 wells. Completing the middle well in the upper part of the zone ahead of the two outer wells in the lower part of the zone, controlled the vertical height growth of the two outer wells. The offset pressure-based analysis proved to be as effective in accurately diagnosing the diverter effectiveness and provided a significant cost and timing advantage compared to other diagnostic techniques.

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Operators continue their quest to better understand and design completion strategies to maximize reservoir contact and optimize well spacing. This paper presents a case study that analyzes completion design effectiveness, using pressure data acquired from isolated monitor stages on offset wells during treatment of adjacent wells. The method was employed on three wells of a seven-well pad in the Marcellus, to assess fracture growth and evaluate the performance of employing intra-stage and inter-stage diversion. Poromechanically-induced pressure responses on isolated monitor stages on offset wells during treatment of an adjacent well, are compared to a fully coupled, three-dimensional, finite element effective stress model, to calculate dominant fracture geometries that correspond to the pressure response induced in the rock. The initiation points and ascending magnitudes of the responses approaching the isolated monitor stage qualify the performance of inter-stage diversion, whereas the fracture growth trends and geometries speak for the efficacy of the intra-stage diversion and overall stage design. The first well utilized inter-stage diversion and dissolvable plugs to isolate stages; the second well utilized intra-stage diversion to improve cluster efficiency with regular frac plugs for zonal isolation; and, the third well employed regular frac plugs with no use of diversion. This presented a unique opportunity to compare and analyze the fracture growth rates, trends, and geometries, while applying inter-stage diversion and frac plug completion designs for zonal isolation on the same pad. This paper is a comparative study to understand the value of using inter-stage diversion, along with dissolvable plugs in place of composite frac plugs, after every stage to attain zonal isolation. In addition, completed stages utilized different fluid designs, providing the opportunity to analyze the impact of fluid design on fracture growth trends and diverter performance. The results are interpreted using pressure data-derived fracture maps with production data, which point to the performance of various completion strategies, using an entirely new diagnostic method.