Conventional truck-mounted seismic vibrator

To demonstrate th e ability of the combination of the new vibrators and the MD -sweep we acquired a zero-offset VSP using a. The EnviroVibe 2 system fits in a shipping container, allowing cost-effective and secure international shipment. The new truck vibrators for VSP surveys provide high output, wide bandwidth with extended low frequencies, low distortion data, together with purpose built carriers which improve safety and logistics for wellsite operations. Figure 8 shows the resulting corridor stacks for the two sweep s plotted between 1. On the left the width of the buggy is. A look inside the black box.

Referring now to Figure 7b, a plot of the contribution of vibrator V A for the survey of Figure 7a is illustrated, where the separation of the contribution from vibrator V A was performed according to the preferred embodiment of the invention. A modified finite element model with reaction mass is built; harmonic response analysis and modal analysis are employed to find out the weak link of the vibrator, which indicates that the supporting column is the weakest component. The device can be roughly cylindrical in shape, about feet long and 6 inches at its widest diameter, so that it can be lowered into a borehole of about 8 inches diameter. Phase control of the force exerted by a seismic vibrator upon the earth's surface ground force is shown to be useful in producing consistent downhole P-wave signatures.

In another embodiment, a device can be buried permanently to provide an inexpensive seismic energy source from a fixed location on a periodic basis. In particular, the ability to separate the vibration signals according to this embodiment of the invention greatly improves the resolution of the survey, since the paths between individual vibrators and geophones may be analyzed, rather than being limited to a generalized analysis of the path between the entire source array and each geophone, as is common in the art. On the generation of low frequencies with modern seismic vibrators. Although each single piezoelectric crystal has limitations on the displacement and force, these limitations can be partially overcome by increasing the number of crystals used, and by stacking them.

Figure 5d shows a case where the system noise is prevalent. Truck-mounted units are especially The maximum force is proportional to the hold-down weight, yet this does not prevent small vibrators from delivering low frequencies within their energy range. Wikimedia Commons has media related to Thumper trucks. The truck mounting makes this system ideal for VSP surveys or traditional seismic surveys done on roads. Affordable broadening of the bandwidth towards the low frequencies down to 2. South African shallow survey post-STM sections.