This paper details the results from a comprehensive study to evaluate completion effectiveness and optimize field development in the Utica. Optimizing the number and location of perforation clusters, number of stages, and treatment size requires a clear understanding of how these parameters affect fracture geometry and well productivity. The goal of this work was to determine how the number of perforation clusters per stage and treatment size affect fracture geometry and well productivity, and to integrate these results into the overall field development optimization.
A comprehensive evaluation of plug and perf (PNP) and controlled entry point (CEP) completions and treatment size was performed using a five-well pad in the Utica (wet gas area). The evaluation included PNP completions with 3-4 perforation clusters and CEP completions with 1-2 perforation clusters. Treatment size was varied by a factor of two to evaluate the effect of fluid volume on fracture length. Microseismic data were gathered on 81 PNP stages and 95 CEP stages. The microseismic data were used to calibrate hydraulic fracture models. Fracture geometries for the five-well pad plus a direct offset well (a six well total of 250+ stages) were discretely gridded in a reservoir simulation model. The reservoir simulation model was calibrated by history matching 14+ months of production data. Proppant Tracer data and DFIT measurements from previous Utica work were used to support the hydraulic fracture modeling and reservoir simulations.
The microseismic data provided a clear understanding of the relationship between treatment size and fracture length for each completion scenario. The results indicate that fracture length may be dependent on completion type, with CEP completions showing less fracture length than PNP completions. Simple production comparisons and detailed reservoir simulation history matching showed that (1) well productivity is governed by the number of perforation clusters, with PNP wells outperforming CEP wells and (2) well-to-well communication is evident. This work did NOT identify any gross inefficiencies with PNP completions and suggests that CEP completions do NOT result in better productivity, at least in this Utica pad.
The calibrated models were used to optimize perf cluster spacing, treatment size, and well spacing for PNP completions. The optimization results are summarized in the paper, but the focus of the paper is the evaluation of PNP and CEP completions, characterization of hydraulic fracture length-volume relationships, and calibration of hydraulic fracture and reservoir simulation models.