7: Multicomponent Interpretation—Case Histories
The case histories presented in this chapter outline some of the interpretation techniques discussed in Chapter 6, and also illustrate how to estimate some of the rock parameters suggested in Chapter 3. Acquisition and processing of the data follows techniques outlined in Chapters 4 and 5.
These case histories illustrate the use of multicomponent interpretation for various types of exploration and development problems. We discuss several applications to demonstrate the flexibility and diverse uses of multicomponent seismology. We begin with a simple study that confirms P-wave “bright spots” as an indication of gas and as an estimation of gas reservoir thickness (Putah Sink, northern California). A similar case history uses Vp/Vs as an indication of gas and estimation of gas reservoir thickness where no “bright spot” amplitude indicator is present (Jeffress Field, south Texas). Lithology estimation is illustrated, along with a measure of the limits of vertical resolution, in the San Miguel example of south Texas, while sandshale estimation, and isolation of channel sands, is demonstrated in the Empire-Abo Field of southeastern New Mexico. Identification of dolomite reservoir within a massive limestone is applied in the Scipio field trend of southern Michigan. Porosity variations in a unit of constant lithology are addressed in the Kingfisher, Okla. data set.
Figures & Tables
Many prospective basins of the world are, or will soon become, “mature” in the exploration sense. Increasingly we must resort to nonconventional technology and techniques to uncover the remaining hydrocarbon reserves that are often found in complex or subtle traps. Multicomponent seismology-the use of concurrent, combined shear (S)- and compressional (P)-wave seismology-is gaining acceptance in the exploration community as one tool that can provide direct measurements of subsurface rock properties. These measurements can detect new hydrocarbon accumulations, and aid in the efficient and economic development of newly found or existing reservoirs by providing detailed maps of reservoir porosity, lithology, and pore fluid distributions.