Log Analysis of Hydrocarbon-Bearing "Shale" Reservoirs

6 March 2015
  |  
Houston, Texas, United States
Who Should Attend
Geologists, geophysicists and engineers involved in exploration for or production from deep-water sand reservoirs will benefit from this practical, hands-on seminar. Participants should have a basic knowledge of stratigraphic principles and fundamentals of sedimentologic processes.
Objectives

By the end of the course participants should be able to:

  • Make a ‘quick-look’ evaluation of seismic profiles for probable exploration targets within passive margin, cratonic basin, forearc and growth-fault systems.
  • Select the most appropriate ‘preliminary’ depositional model as an interpretation template for seismic analysis.
  • Plan an interpretation strategy to optimize identification of deep-water sand systems including channel, channel-complex, lobe and sheet facies.
  • Identify reservoir connectivity issues for channel-complexes and sheet-sands and outline a strategy for testing predicted connectivity.
  • Identify the most critical issues of play-risk for each depositional element of deep-water sand systems.
Course Content

This one day course will include background material on hydrocarbon-bearing shales, methods of evaluation, and case studies of both gas and oil bearing shales. The course begins with a quick review of general information about hydrocarbon-bearing shales that will include: 1) areal distribution, 2) classification, 3) hydrocarbon resources, 4) key geological and engineering parameters, 5) a comparison of the mineralogy of an average shale to a hydrocarbon-bearing shale, 6) shale porosity and permeability, and 7) an expected shale production model. Next the log parameters [Rt, GR, ρb, ΦNls, and Pe] used for a quick log scan evaluation are presented along with the standard quick-look methods [Ro, Rwa, and Φw]. All of these quick methods are designed so that the geologist or engineer can evaluate the potential shale to determine if a more detailed log analysis is required. The parameters included in a more detailed log analysis include the determination of: 1) total organic carbon (TOCwt%), 2) effective porosity (Φe), 3) effective water saturation (Swe), 4) hydrocarbon-filled porosity (Φgas or Φoil), and 5) permeability (k in nannodarcies). There is also a section that reviews the methods that can be used to determine formation water resistivity (Rw) in shales.

The methods for determining the thermal maturity of organic shales will include: 1) vitrinite reflection (Ro), 2) coloration of spores and conodonts, and 3) determination of thermal maturity from log data [Maturity Index (MI; Zhao & others, 2007)]. The determination of thermal maturity is an important step in the analysis of an organic shale, because the level of maturity (i.e. oil or gas) determines how the log data will be analyzed. The next step is the determination of TOC(wt%) from log data. The methods outlined are Passey & others (1990), the Schmoker Equation, and uranium content from spectral gamma ray logs.

If the potential shale is a gas reservoir the next step is the determination of the adsorbed gas content (gc in SCF/ton). The two methods for determining adsorbed gas content that will be outlined are the Langmuir Isotherm and the TOC versus gc (SCF/ton) methods. A flow chart is provided to guide the geologist/engineer through the analysis. For example if the TOC(wt%) is greater than 2% the analysis should proceed to the next step the determination of: 1) volume of kerogen (Vke), 2) Volume of clay (Vcl), 3) volume of quartz (Vqtz), and total porosity (Φtotal) using the simultaneous equation method developed by Rick Lewis w/ Schlumberger.

Using the results from the simultaneous equations the total porosity (Φtotal) in corrected to effective porosity (Φe) using the volume of clay (Vcl) and the porosity of the clay (Φclay), and the effective water saturation (Swe) is calculated.

Then if the potential is a gas reservoir adsorbed gas content (gc SCF/ton) is converted to gc in SCF/Area and free OGIPscf (gas) or OOIPstb (oil) is calculated using the effective water saturation (Swe) and effective porosity (Φe). Permeability (k in nannodacies) is calculated using hydrocarbon-filled porosity (Φgas or Φoil).

There is a review of the application of non-standard well logs to the log analysis of hydrocarbon-bearing shales that includes Nuclear Magnetic Resonance (NMR) imaging logs, Geochemical logs, and SWS Multi-Frequency Polarized Dielectric Scanner. Next is a review of the Array Sonic logs, and their use in the evaluation of horizontal stresses and orientations [maximum (σHmax) and minimum (σHmin)] and fracture orientations, and the calculation of Brittleness Index.

Six case studies including the Devonian Woodford Shale [GAS], Jurassic Haysville Shale [GAS], two Permian Leonard shales [OIL], and two Permian Wolfcamp shales [OIL] are presented to illustrate the methods outlined in the course. OOIPstb or OGIPscf values in wells with GEOCHEM Log data will be compared to OOIPstb or OGIPscf determined using only a standard logging suite. At the end of this section is a list of an ideal data base (logs and core data) for hydrocarbon shale analysis.

Course notes will be provided in digital format on USB flash drive only, so electronic devices with a USB port are required for all courses. If you do not have access to an electronic device with a USB port, please contact the AAPG Education Dept. for an alternate method to download the digital course notes.

Houston, TX - Norris Conference Center - CityCentre
Houston, TX - Norris Conference Center - CityCentre
816 Town & Country Lane, Suite 210
Houston Texas 77024
United States
(713) 590-0950
50 people
Limit
1.5
CEU
Compare to the Whole Conference Pricing
$2,095
Expires on
01 November, 2014
Member Tuition
$2,395
Expires on
06 March, 2015
Nonmember Tuition

Last date for cancellation with a refund is February 2, 2015. No refunds AFTER February 2, 2015. Five-day full-week badges can be transferred to a friend or colleague if you can’t attend all week. Courses also individually priced if you can’t come for the full week.

Scholarship assistance for laid-off workers may be available.  Email the AAPG Education Dept. for details.

 

Creties Creties Jenkins Rose and Associates, Houston, TX USA
Lesli Lesli Wood Colorado School of Mines, Golden, CO
Ernest Ernest Mancini Department of Geological Sciences, University of Alabama
Donald Donald Herron Independent Geophysical Consultant
Robert C. Robert C. Wegner Rice University, Houston, Texas, USA
Dana S. Dana S. Ulmer-Scholle Scholle Petrographic LLC
Peter A. Peter A. Scholle Scholle Petrographic LLC
Kurt J. Kurt J. Marfurt ConocoPhillips School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma, USA
John M. John M. Armentrout Cascade Stratigraphic Inc.
Art Art Saller Cobalt International Energy, Houston, Texas, USA
Christopher D. Christopher D. Laughrey Weatherford Laboratories, Golden, Colorado, USA
George B. George B. Asquith Texas Tech University, Lubbock, Texas, USA
Fred Fred Hilterman Geokinetics Data Processing, Houston, Texas, USA
Debbi Debbi Boonstra Education Manager +1 918 560-2630

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