− | An ''[[Mapping with two-dimensional seismic data#Time interval maps|isochron map]]'' is a contour map of equal values of seismic traveltime between selected events.<ref name=pt06r141 /> Isochron maps are the seismic analog of isochore maps and, as such, are intended to derive thickness information from seismic data. Isochroning between events above and below a pay horizon, for example, would estimate pay thickness. Renick and Gunn<ref name=pt06r109>Renick, H. Jr., Gunn, R. D., 1989, Triangle Ranch Headquarters field development using shallow core holes and high-resolution seismic data: Geophysics, v. 54, n. 11, p. 1384–1396, DOI: [http://library.seg.org/doi/abs/10.1190/1.1442602 10.1190/1.1442602].</ref> present a good case history of using isochron and time-structure maps to generate “isopach” and elevation-structure maps. Their isochron-isopach approach delineated reef trends for further development drilling and used well penetrations through a shallow horizon for depth control on a deeper horizon. Phipps<ref name=pt06r99>Phipps, G. G., 1989, Exploring for dolomitized Slave Point carbonates in northeastern British Columbia: Geophysics, v. 54, n. 7, p. 806–814, DOI: [http://library.seg.org/doi/abs/10.1190/1.1442709 10.1190/1.1442709].</ref> documents the pros and cons of using isochron thins and structural highs as exploration drilling criteria for dolomitized Devonian limestones. | + | An ''[[Mapping with two-dimensional seismic data#Time interval maps|isochron map]]'' is a contour map of equal values of seismic traveltime between selected events.<ref name=pt06r141 /> [[Isochron]] maps are the seismic analog of isochore maps and, as such, are intended to derive thickness information from seismic data. Isochroning between events above and below a pay horizon, for example, would estimate pay thickness. Renick and Gunn<ref name=pt06r109>Renick, H. Jr., Gunn, R. D., 1989, Triangle Ranch Headquarters field development using shallow core holes and high-resolution seismic data: Geophysics, v. 54, n. 11, p. 1384–1396, DOI: [http://library.seg.org/doi/abs/10.1190/1.1442602 10.1190/1.1442602].</ref> present a good case history of using isochron and time-structure maps to generate “isopach” and elevation-structure maps. Their isochron-isopach approach delineated reef trends for further development drilling and used well penetrations through a shallow horizon for depth control on a deeper horizon. Phipps<ref name=pt06r99>Phipps, G. G., 1989, Exploring for dolomitized Slave Point carbonates in northeastern British Columbia: Geophysics, v. 54, n. 7, p. 806–814, DOI: [http://library.seg.org/doi/abs/10.1190/1.1442709 10.1190/1.1442709].</ref> documents the pros and cons of using isochron thins and structural highs as exploration drilling criteria for dolomitized Devonian limestones. |