3D imaging of a reservoir analogue in point bar deposits in the Ferron Sandstone, Utah, using ground‐penetrating radar

Abstract

Most existing reservoir models are based on 2D outcrop studies; 3D aspects are inferred from correlation between wells, and so are inadequately constrained for reservoir simulations. To overcome these deficiencies, we have initiated a multidimensional characterization of reservoir analogues in the Cretaceous Ferron Sandstone in Utah. Detailed sedimentary facies maps of cliff faces define the geometry and distribution of reservoir flow units, barriers and baffles at the outcrop. High‐resolution 2D and 3D ground‐penetrating radar (GPR) images extend these reservoir characteristics into 3D to allow the development of realistic 3D reservoir models. Models use geometric information from mapping and the GPR data, combined with petrophysical data from surface and cliff‐face outcrops, and laboratory analyses of outcrop and core samples. The site of the field work is Corbula Gulch, on the western flank of the San Rafael Swell, in east‐central Utah. The outcrop consists of an 8–17 m thick sandstone body which contains various sedimentary structures, such as cross‐bedding, inclined stratification and erosional surfaces, which range in scale from less than a metre to hundreds of metres. 3D depth migration of the common‐offset GPR data produces data volumes within which the inclined surfaces and erosional surfaces are visible. Correlation between fluid permeability, clay content, instantaneous frequency and instantaneous amplitude of the GPR data provides estimates of the 3D distribution of fluid permeability and clay content.

Semblance response to a ground‐penetrating radar wavelet and resulting errors in velocity analysis

“…; Zeng et al . , Moysey and Knight ). Stacking quantities output from velocity analysis are therefore the most accurate estimate of a true velocity distribution that is readily available.…”

Laser rangefinders and ArcGIS combined with three-dimensional photorealistic modeling for mapping outcrops in the Slick Hills, Oklahoma

“…Methods and technology developed in geographic information system (GIS) mapping applications, such as remote sensing, are used in geologic mapping, but for detailed mapping of exposures on steep slopes and cliffs it is necessary to map digitally and obliquely at relatively close range (often <1 km) using portable and perhaps handheld equipment. Refl ectorless laser rangefi nders (Gilbert, 1996) such as handheld guns and total stations (Lyman et al, 1997;Nielsen et al, 1999Nielsen et al, , 2000Xu et al, , 2001Zeng et al, 2004;Xu, 2000;Ramirez-Ugalde, 2002) have been an effective technology for geological mapping, operating at 1-250 points/s out to ranges of as much as 1 km and vertical and horizontal angle accuracy as precise as 0.001° (total station) and 0.01° (handheld rangefi nders). Terrestrial laser scanners (TLS) programmed to run at high speed (thousands to hundreds of thousands of points per second) generate dense point clouds (millions of points) at angle and range accuracies better than the handheld rangefi nders.…”

Three-dimensional facies architecture and three-dimensional calcite concretion distributions in a tide-influenced delta front, Wall Creek Member, Frontier Formation, Wyoming

“…Ground-penetrating radar (GPR) has been used for detailed subsurface imaging of deltaic deposits since the early 1990s; however, most studies have focused on modern deltas associated with unconsolidated fluvial deposits (Jol and Smith, 1991;Pepola and Hickin, 2003;Roberts et al, 2003), instead of ancient marine environments exposed in outcrops. Although GPR has revealed high-resolution structural information in fluvial sediment bodies and has been used to build reservoir models (McMechan et al, 1997;Corbeanu et al, 2001;Zeng et al, 2004), few examples document detailed threedimensional (3-D) delta-front facies architecture (Lee et al, 2005), and there are no studies of 3-D cement distribution. Preserved delta fronts in outcrops are commonly characterized by prograding clinoforms and systematic variations in sedimentary facies (Bhattacharya and Walker, 1992;Snelgrove et al, 1996Snelgrove et al, , 1998.…”