Charlotte Sullivan

Visualization and characterization of structural deformation fabric and velocity anisotropy

Fractures develop with different intensity and preferred orientations in response to changing stress regimes throughout geologic time. Fractures with preferred orientations are often interpreted as the cause of seismic P-wave velocity (Vp) anisotropy as well as linear features seen in seismic attribute volumes. Field experiments show that stress orientation can often be directly measured by P-wave anisotropy while the lineaments seen in the volumetric curvature attributes are related to deformation.

Seismic detection of paleocave system and its influence on carbonate reservoir compartmentalization

prediction of the 3-D distribution of the system. In this study, we focus on part of the east central flank of the Central Basin platform and develop a method of paleocave system identification by integrating core and log, seismic inversion and 3-D geometric attribute analysis. Using results of this seismic characterization, we further explore an island hydrologic model to explain the development of the paleocave system and its control on the reservoir compartmentalization of the field. Method Using available core data in two cored wells, we first identify the karst features and their related collapsed paleocave packages in the San Andres Formation. For the high volume area of the field where both core and log data are available, we interpret the collapsed karst features using well log data calibrated by core description. We then perform model-based seismic impedance inversion to determine the distribution of the collapsed paleocave system. For the transitional zone from the platform to the basin where well logging and core data are not available, geometric seismic attributes, including the coherence and multispectral curvatures, are calculated to detect the flank collapsed paleocave system. Integrating the hydrologic and structure features with the sequence stratigraphy of the in San Andres Formation, Permian Basin (French and Kerans, 2004), we recommend a geological model for the mechanism of the development of the collapsed paleocave system for the studied field. Interpretation and analysis

Introduction to special section: CO2 storage and utilization

Monitoring, verification, and accounting (MVA) activities are critical to assess storage site performance and meet the regulatory requirements of the new Class VI Underground Injection Control Program for Carbon Dioxide (![Formula][1] ) geologic sequestration. MVA programs are designed and

Introduction to special section: Karst

The term karst derives from the name of an area of Slovenia and generally refers to the result of weathering or dissolution of limestone, dolomite, anhydrite, or other soluble rocks. Karst and ancient, buried karst (paleokarst) affects hydrocarbon exploration and production, hydrogeology, and near-

Introduction to special section: Multicomponent seismic interpretation

Multicomponent seismic data allow geologic sequences to be defined with both P-waves and S-waves. These two distinct types of body waves provide different options for defining stratigraphy and facies within stratigraphic intervals. Either wave (P or S) can propagate as fast and slow modes in

Seismic attribute delineation of lineaments and reservoir compartmentalization: An example from the Devonian Dollarhide field, Central Basin Platform, west Texas

Reservoir compartmentalization of the Dollarhide Field has to be understood in order to optimize recovery of remaining reserves. Porosity and permeability heterogeneity is a function of the interaction of stratigraphic and structural elements such as fractures, faults, subcrops and channels. Diagenesis and dissolution play an important role on the heterogeneity of the reservoir. Some of the reservoir-scale features are small and beyond the resolution of conventional seismic. Research is being conducted on the use of 3D seismic attributes to better delineate reservoir parameters important for fluid flow models. This paper presents our current understanding of the lineaments of the field after using some computed 3D seismic attributes. Coherence with two passes of edgepreserving smoothing has been a helpful attribute. The Dollarhide Field is a north-south trending asymmetric anticline bound by major reverse faults on its east flank. The anticline is associated with a northeast striking, rightlateral, strike-slip fault, and it is cut by an en-echelon system of northeast striking, right lateral, synthetic, Riedelshear faults. Conjugate, northwest striking, antithetic shear faults have been identified on the downthrown block of the field. Some lineaments in the upthrown block with the same trend could have the same origin. The structure was formed during the Late Paleozoic orogeny as the result of the collision of North and South American plates, when the Central Basin Platform was uplifted. The structure is truncated at its crest by the unconformity at the base of Early Permian carbonates. Subcropping belts of carbonates, cherts, and shales show the configuration of the structure before Early Permian times. Reactivation of pre-existing faults may have occurred during Early Tertiary Laramide orogeny. When compared with porosity-thickness maps of the reservoirs, the subcrop pattern and conjugate shear faults show a strong correlation with porosity trend segmentation.

Seismic stratigraphy, reservoir characterization, and seismic 3‐D visualization of seismic attributes of carbonate facies and karst in the San Andres Formation, Vacuum Field, Lea County, New Mexico

Mature carbonate reservoirs of the Permian San Andres in the Delaware Basin have low recovery efficiencies due to compartmentalization by reservoir scale heterogeneity. The San Andres was deposited on a shallow, open to restricted marine shelf. Seaward progradation of individual shallowing upward cycles and lateral facies shifts created heterogeneity on a reservoir scale. The most productive reservoir rocks are the oolitic, peloidal packstones and grainstones found in the middle ramp to outer ramp. Permeability barriers include tight anhydrite cemented wackstones and mudstones of the peritidal through ramp facies, and anhydrite cemented karst features associated with exposure surfaces.