For What Reason Do We Use Depth Conversion?
Seismic reflection information records the two-way travel time (TWT) to a reflection occasion from the surface. Depth conversion is the cycle by which deciphered seismic skylines (and time area seismic itself) are changed over from the movement time-space to the depth area. (Note that depth movement is a seismic imaging method that improves reflector situating. Depth relocated information is regularly changed over back to time and afterward depth changed over traditionally as this gives more noteworthy adaptability for testing elective speed models.)
Depth conversion can be basic or complex. Ways to deal with the method differ everywhere in the world and are reliant on the play situation and land overburden. Depth conversion is a major, specialized subject for a short article, so we will attempt to offer some broad remarks and feature a couple of focuses that are maybe less generally known.
At the point when expectations of Depth conversion are made at various normal focuses on a matrix design then we will in general view the outcome as a depth surface. Smooth, best gauge anticipated depth surfaces of this sort are utilized for different purposes including penetrating visualization (well figures), set up hydrocarbon volume assessment (surfaces), and supply displaying (surfaces).
The standard practice utilization of depth surfaces for making depth visualization for well focusing on intentions is altogether legitimate. Nonetheless, the utilization of similar surfaces for setting up hydrocarbon volume assessment isn’t legitimate.
Understanding Rock Velocity
To change over time reflections to a profundity surface we need to know the velocity. The profundity is then assessed from the straightforward geophysical relationship that profundity = velocity x time.
The velocity of a rock is a principal actual property identified with its hardness.
As a straightforward dependable guideline, on the off chance that you hit a rock with a geographical mallet.
For profundity change, velocity differs with rock type, the profundity of entombment, and pore space factors, for example, porosity and the presence of microfractures. As a rule, the slowest velocity we experience would be ocean water, which is ordinarily 1,500 m/s.
The quickest speeds we regularly go over would be the framework velocity of rocks like sandstones, limestones, and dolomites.
And volcanic rocks, where the velocity arrives at 6,000–6,500 m/s.
Using Seismic Velocities
Without good data, the lone wellspring of speed information is through the seismic handling going with seismic reflection information. Depth Conversion has some valuable qualities – for instance, they cover the study territory with moderately thick examining. Shockingly, seismic velocities are conceivably mistaken, coldhearted toward speed changes in more profound layers, and loud. In view of the commotion, seismic velocities ought to be sifted or smoothed before use. Kriging utilizing an unequivocal piece (commotion) model is a decent decision for this errand.
Seismic velocities can be utilized as a normal speed to a skyline for single layer profundity change.
or the Dix equation can be utilized to change over to stretch velocities for use in a multi-layer profundity transformation. Seismic velocities are incorrect (one-sided) and can over-or disparage the genuine speed by as much as 10–20%.
Resultant profundity visualization will have comparable mistake sizes, yet the vulnerability in gross stone volume.
(GRV) is less influenced by inclination in the speed field than it is by neighborhood variety thus the GRV vulnerability will be less influenced.