How and Where Wells Talk: Integrating Cross-Well Strain and Production Profile Interference Testing

Abstract

Objectives/ScopeIn the Permian Basin frac locations, azimuths and intensities recorded by single-use distributed fiber optics in two wells are integrated and compared to post-flow back production allocation and interference testing acquired with intervention fiber optics to identify areas of hydraulically conductive fracs and communication between offset wells.Methods, Procedures, ProcessTwo wells on an 8 well pad were monitored with single-use pump down fiber. Strain events are recorded, identifying magnitude, azimuth, frac dimensions and velocity of the frac'd stages in purview of the monitor wells. 60 days post flowback, two of the frac'd laterals are sensed using intervention fiber optics to evaluate production allocation at the cluster level. Offset wells are then shut-in and production changes in the sensed well indicate the location and magnitude of interconnection between the sensed well and offsets. Strain data is compared to interference data to determine if strain could be associated with future productivity.Results, Observations, ConclusionsAreas where cross-well strain indicated connective fractures also showed increases in production via interference testing. Areas with poor or no strain activity indicated reduced production and little, if any offset interference.Novel/Additive InformationExtrapolating observed strain events identified areas where frac tips overlapped and appear to have created conductive pathways between offset wells, where interference is noted, despite an absence of strain data (as the farther fracs did not reach the monitor well but did overlap the offset that was sensed for flow allocation). This indicates that the production allocation interference testing method appears to reveal hydraulically connected fractures, even in the absence of strain data.