This paper extends the single well reservoir modeling concepts documented in Raterman et al. 2019 to a multiwell pilot. The analysis integrates multiple data sources to provide a holistic view of spatial drainage and interwell interference in a multiwell context. The pilot employed a four well staggered high-low configuration. All wells were kitted with bottom hole pressure and fiber optics. A vertical well was employed to monitor microseismic and pressure during the completion and production phases of the pilot. In-well and cross-well DAS, DTS and pressure data were integrated in a full pattern reservoir model to history match production, interwell interference and far field pressure data. The history matched model indicates that spatial drainage remains somewhat localized and patchy in the interwell context given the pilot spacing and completion designs. Interference between wells is significant and is largely mediated through high conductivity, limited volume conduits between wells. Although these conduits facilitate interference, a strong competitive drainage scenario between wells is not concluded. These insights are invaluable in determining the efficacy of the employed completion and spacing design; and suggest further improvements for future designs. Finally, the model was extended to analyze a Pump-into-Parent (PIP) test conducted in a partially depleted pilot producer. Fracture dilation was evidenced.
In the quest for optimal well spacing and stacking configurations in shale plays, it is an oft-stated presumption that interwell interference is to be avoided (Fiallos, et al., Rucker, et al.). It is our experience, however, that communication between wells is established via hydraulic fracturing to distances routinely exceeding 1000 feet (Raterman, et.al., 2018); hundreds of feet beyond what would be considered an appropriate interwell spacing distance for tight rocks. Moreover, it appears that interwell communication is established fairly early in the pumping operation suggesting that even a radical alteration of the completion design may have limited impact on the outcome. Therefore, it would seem that the likelihood of interference is a fact of life and must be dealt with in the context of single well production degradation as a function of interwell distances, stacking configuration, completion design and potential parent well interactions.