This paper uses an experimental seismic line recorded with three‐component (3C) receivers to develop a case history demonstrating very little benefit from receiver arrays as compared to point receivers. Two common array designs are tested; they are detrimental to the P‐S wavefield and provide little additional benefit for P‐P data. The seismic data are a 3C 2‐D line recorded at closely spaced (2 m) point receivers over the Blackfoot oil field, Alberta. The 3C receiver arrays are constructed by summing five (one group interval) and ten (two group intervals) point receivers. The shorter array emphasizes signal preservation while the longer array places priority on noise rejection. The effectiveness of the arrays versus the single geophones is compared in both the t−x and f−k domains of common source gathers. The quality of poststack data is also compared by analyzing the f−x spectra for signal bandwidth on both the vertical receiver component (P‐P) and radial receiver component (P‐S) structure stacks produced using these two array design philosophies. The prestack analysis shows that the two arrays effectively suppress coherent noise on both the vertical and radial geophone data and perform reasonably as spatial antialias filters. The poststack analysis reveals that, for both the P‐P and P‐S data, neither of the two arrays significantly improves the quality of the final seismic image over that obtained from point receiver data. For the P‐P data there are subtle differences between the final stacked sections, while for the P‐S data there is a significant deterioration in image quality from the application of the arrays. This P‐S image deterioration is attributed to significant variation of shear‐wave statics across the array. For this specific survey area and acquisition parameters, 3C receiver arrays are unnecessary for P‐P data and are detrimental to P‐S data.

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In 2016-2017 a range of analyses and applications of a geometrical model of fibre-optic (DAS) data for arbitrary fibre shapes was described. Amongst those applications was a multicomponent estimation scheme based on a careful accounting, and combined useage, of the varying fibre directions associated with a shaped cable layout. In 2018 a prototype shaped DAS fibre array was buried at the Containment and Monitoring Institute Field Research Station in Newell County AB to put some of these ideas and their feasibility to the test. The loop was illuminated from several directions, and shot records were analyzed to assess if directional sensitivity is sufficient to permit multiple components of strain to be estimated simultaneously. By picking a P-wave arrival and comparing it to an analytic model, we conclude with a cautious "yes". The size of the loop (roughly 10m on a side) was chosen to accommodate standard DAS gauge lengths; at this size, horizontal but not vertical strain rate components were sensed. Future versions designed for gauge lengths on the order of 2m will permit 6-component estimation.

During November 1997, the CREWES Project at the University of Calgary acquired a high-resolution seismic survey at the Blackfoot field located east of Calgary. The 3 km 3C-2D survey consisted of recording dynamite shots into "low-resolution" (20 m), high-resolution (2 m) and buried (6, 12 and 18 m) receiver arrays. A walk-away AVO VSP was also acquired by simultaneously recording the shots at four different depths in a well adjacent to the seismic profile.Shot gathers of both vertical and radial components show good reflection data with a high signal-to-noise ratio. The transverse component data appears to contain very little reflection energy. Structural and migrated P-P and P-S stacks of the "low-resolution", high-resolution and buried portions of the survey posses a high S/N ratio. A cursory examination of these sections show that they adequately image the target area. The analysis of the data from all the different portions of the survey remains as future work. Figure 1. Map showing the location of the PanCanadian Blackfoot field.