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Title: Characterization of Unconventional Reservoirs: CO2 Induced Petrophysics; Abstract #214865

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Publication Date:
Research Org.:
National Energy Technology Lab. (NETL), Pittsburgh, PA, and Morgantown, WV (United States). In-house Research
Sponsoring Org.:
USDOE Office of Fossil Energy (FE)
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Resource Relation:
Conference: 2017 American Geophysical Union Fall Meeting; New Orleans, LA December 11-15, 2017
Country of Publication:
United States
04 OIL SHALES AND TAR SANDS; 58 GEOSCIENCES; shale, carbon storage, petrophysics, electron microscopy, computed tomography

Citation Formats

Verba, C., Goral, J., Washburn, A., Crandall, D., and Moore, J. Characterization of Unconventional Reservoirs: CO2 Induced Petrophysics; Abstract #214865. United States: N. p., 2017. Web.
Verba, C., Goral, J., Washburn, A., Crandall, D., & Moore, J. Characterization of Unconventional Reservoirs: CO2 Induced Petrophysics; Abstract #214865. United States.
Verba, C., Goral, J., Washburn, A., Crandall, D., and Moore, J. 2017. "Characterization of Unconventional Reservoirs: CO2 Induced Petrophysics; Abstract #214865". United States. doi:.
title = {Characterization of Unconventional Reservoirs: CO2 Induced Petrophysics; Abstract #214865},
author = {Verba, C. and Goral, J. and Washburn, A. and Crandall, D. and Moore, J.},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2017,
month =

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  • Currently reservoir characterization plays a very important role in the reservoir management projects, aimed at optimizing the exploitation of a reservoir. Petrophysical studies are a very important part of the characterization effort, and are especially advantageous when complex reservoirs, such as vuggy and fractured carbonates, are to be developed. The main purpose of core analysis is to obtain data representative of in-situ formation properties. Coring technology has advanced significantly in recent years in order to achieve the goal of optimal development. The purpose of this paper is to present results of petrophysical whole core analyses carried out in highly permeablemore » cores, intensively vugular and fractured. The estimated parameters were multidirectional permeability tests k{sub H{theta}} and k{sub V}, matrix {phi}{sub ma} and fracture porosity {phi}{sub fb}, relative permeabilities k{sub ro} and k{sub rw}, and the high-velocity flow coefficient {beta}. A new correlation for this {beta} coefficient is presented for conditions of these highly macro vugular formations.« less
  • One of the most important issues in reservoir characterization is heterogeneity. Reservoirs are more heterogeneous than researchers have believed in the past. Reservoir heterogeneity can be created by complex sedimentary and diagenetic processes and then modified by a sequence of tectonic changes. The petrophysical and seismic properties of reservoirs may vary significantly from one well to another or even at a distance of a few meters. Therefore, if one could predict such rock property variations in space, it would be very beneficial to reservoir characterization and planning of appraisal and production wells. moreover, front movement in a water flooding maymore » be monitored by studying the different seismic response between water and hydrocarbon saturated rocks. In this paper a new method for predicting the spatial variation in rock and fluid properties is presented along with laboratory results na da case study. Various models of porosity, permeability, pore-fluid, and lithology are created to predict the corresponding P- and S-wave velocities and acoustic impedances. The best fit between synthetic seismic and sonic models would indicate the most probably reservoir model. This method could be useful in (1) Reservoir Characterization: Predicting the spatial a variation rock and fluid properties of a reservoir. This is essential for accurate reservoir characterization and planning of appraisal and production wells; (2) Formation Evaluation: Modeling porosity, permeability and pore-fluids near the wellbore in conventional and horizontal wells; and (3) Seismic Exploration: Direct detection of hydrocarbon bearing rocks in areas for which little subsurface information is available.« less
  • Cretaceous conventional and unconventional fractured reservoirs in the southern Powder River basin, Wyoming, are associated with small throw (10 to 30 ft) normal faults. The faults are nearly vertical, trend northwest-southeast and northeast-southwest, and probably are basement derived. The faults are most easily identified in Cretaceous marine shales and are exposed at the surface in Tertiary units. Erosion and subsequent deposition of Cretaceous sandstones, limestones, and shales affected by the extensional normal faults form stratigraphic traps. The reservoirs are interbedded with, or composed of, mature source rocks have generated and expelled significant hydrocarbons. Overpressuring from the maturation and expulsion processesmore » is still present and has preserved open fractures and porosity in reservoirs from the Lower Cretaceous Fall River through the Upper Cretaceous Niobrara formations. The faults have offset thin sandstone reservoirs forming permeability barriers. The faulting and associated fractures have provided pathways for organic acids that assisted formation of secondary perosity in Upper Cretaceous sandstones. The fracturing of mature source rocks provides areally extensive unconventional reservoirs. Fracturing associated with the extensional normal faults provides significant exploration and exploitation potential for the use of horizontal drilling techniques to evaluate multiple, fractured, overpressured conventional, and unconventional reservoirs that may contain large reserves.« less
  • The reservoir engineer involved in the development of unconventional gas reservoirs (UGRs) is required to integrate a vast amount of data from disparate sources, and to be familiar with the data collection and assessment. There has been a rapid evolution of technology used to characterize UGR reservoir and hydraulic fracture properties, and there currently are few standardized procedures to be used as guidance. Therefore, more than ever, the reservoir engineer is required to question data sources and have an intimate knowledge of evaluation procedures. We propose a workflow for the optimization of UGR field development to guide discussion of themore » reservoir engineer's role in the process. Critical issues related to reservoir sample and log analysis, rate-transient and production data analysis, hydraulic and reservoir modeling and economic analysis are raised. Further, we have provided illustrations of each step of the workflow using tight gas examples. Our intent is to provide some guidance for best practices. In addition to reviewing existing methods for reservoir characterization, we introduce new methods for measuring pore size distribution (small-angle neutron scattering), evaluating core-scale heterogeneity, log-core calibration, evaluating core/log data trends to assist with scale-up of core data, and modeling flow-back of reservoir fluids immediately after well stimulation. Our focus in this manuscript is on tight and shale gas reservoirs; reservoir characterization methods for coalbed methane reservoirs have recently been discussed.« less
  • Abstract not provided.