1. DHIs: Fluid Contacts
Hydrocarbons are lighter than water and tend to form flat events at the gas/oil contact and the oil/water contact.
Thicker Reservoir
Fluid contact
event
Slide 20
Here are two more seismic models (with added noise) to illustrate a fluid contact reflection
Note the “hockey stick” in the upper image
For the lower image, the reservoir is thinner we only see the fluid contact, not the handle portion of the “hockey stick”
IMPORTANT – a fluid contact will be flat (horizontal) in depth, unless there is a hydrodynamic gradient causing it to tilt
Since we are looking at data in the time domain, there can be some distortions if the velocities above the reservoir
vary laterally and cause a flat event in time to be tilted on a time section
Thinner Reservoir
Fluid contact
event
Courtesy of ExxonMobil
L12 – Data Analysis