Abstract
Unconventional reservoirs pose unique challenges for petrophysical model development, including: wide variability in volumes, of minerals and organic constituents, fine-scale facies laminations, variable rock-fluid wettability, problematic identification of subsurface fluid phases, and unsatisfactory water saturation models. Often, more conventional petrophysical models are applied, but these require significant and careful calibration of model parameters with core data. Complicating model calibration is the wide variability of rock facies within stratigraphic bounding units and geographic changes in rock facies. Geographic extension of an area of interest requires more core data to recalibrate models that no longer work effectively. Although specialty log data are very helpful in pilot holes, many operators need models calibrated to triple combo data that can be applied to vertical wells for mapping of petrophysical properties. How does one know when to apply one model and not another? How can models be developed that are both efficient to apply and more effective in multiple stratigraphic units over a wider geographic area? We present a rationale and workflow for developing and applying log facies-based petrophysical models, using the Delaware Basin as an example. In this study, our workflow integrates data from the petrophysical analysis of log data from over 400 wells, core data from over 50 wells.
For the unconventional petrophysical workflow, we determine all petrophysical model parameters within either a log facies and/or stratigraphic framework utilizing triple combo wireline log data and map profiles of rock maturity. Fluid parameters are modeled using profiles of rock maturity and stratigraphically constrained profiles of produced oil-and-gas ratios. Log facies are calculated using techniques including k-means cluster analysis and self-organized maps. Log facies capture a more accurate estimation of petrophysical properties that vary with rock facies than more simplistic log cut-off based lithologic models. Facies-based petrophysical properties are calibrated to core data using multivariate regression and data mining techniques to develop empirical relationships for mineralogy, organic content, porosity, and saturation model parameters.
Mineral and organic weight percent estimates from XRD and TOC are converted to volumes by optimizing the match between calculated grain density and measured core grain density. TOC, mineral and organic constituent volumes, and matrix dry grain density are modeled using multivariate regression of wireline log data and estimated rock thermal maturity. Formation fluid densities are estimated by optimizing the match between calculated density porosity and core porosity using multivariate regression of rock maturity and produced oil and gas ratio profiles. Multiple methods are used to estimate fluid saturations as often no single method is entirely satisfactory. Data mining techniques are used to develop potential empirical relationships between fluid volumes and mineral or organic constituents. Parameters for standard resistivity saturation models for each log facies are determined by optimizing the match between calculated and measured core saturations.
Speaker Biography
Margaret Lessenger is a consulting petrophysicist at Rimrock Petrophysics and Analytics, LLC in Denver, Colorado. She has over 30 years of experience as a geophysicist, geologist, and petrophysicist working various basins in onshore United States, offshore Gulf of Mexico, and North Sea. In the past 3 years of consulting, she has developed numerous petrophysical models in unconventional plays for both small and large operators. She has worked for the Superior Oil Company, ARCO Oil and Gas, Platte River Associates, the Colorado School of Mines Department of Geology, Williams Exploration, and Newfield Exploration. Lessenger holds a BS in Geophysical Engineering, MS in Geophysics, and PhD in Geology (stratigraphy and sedimentology) from the Colorado School of Mines. She has given numerous professional presentations and has been an SPWLA Distinguished Lecturer. She is a member of SPWLA, SPE, AAPG, and SCA.
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When
Tuesday, March 19, 2019
11:20 am - 1:30 pm
Where
Wynkoop Brewing Company
(tell me how to get there)
Cost
$25 per person
$30 at the door (space permitting)
Next Month's Talk
The Expansive Case for Magnetic Resonance Logging
Marcus Donaldson
Mount Sopris Instruments
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From the President
Shannon Borchardt
I am truly excited by the attendance, energy level, and enthusiasm we have seen at the last two monthly luncheons with over 70 people attending each month. Thank you to the presenters Aidan and Jesus, to Patricia for lining up the great presentations, and to all of you in this society for your participation. Let’s keep up the enthusiasm in March where we will hear from Margaret Lessenger.
Our spring workshop is almost here, so sign up if you haven’t already. It will be April 3rd in Golden with the topic of ‘Data Analytics in Reservoir Evaluation’, but the registration deadline is Wednesday, March 13th. We have a great technical lineup, as well as a social/happy hour at the end of the day. This happy hour will replace the summer social that has taken place in previous years.
Lastly, the 2019 DWLS-RMAG Symposium will take place on October 22 with a theme of ‘Multiscale Imaging for Reservoir Optimization.’ If you are interested in submitting an abstract or sponsorship opportunities, please contact Katerina Yared.
As always, please contact me if you have any suggestions to continue to improve DWLS.
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From the VP - Technology
Patricia Rodrigues
The DWLS Spring workshop on Data Analytics in Reservoir Evaluation is coming to Denver on Wednesday, April 3rd, 2019. It will be held from 7:30 to 4:00 pm at the American Mountaineering Center in Golden, followed by a happy hour at the Mountain Toad Brewery across the street and sponsored by Emerson/Paradigm (1 drink ticket per person).
Registration is now open and the cost for members is $135, non-members $195, and students $35. To get either the member or student price you must use the links in the emails sent out on January 31st. Registration includes breakfast, box lunch, refreshments and an electronic copy of the booklet. The registration deadline is Wednesday, March 13th.
The final agenda for the workshop is complete with speakers from O&G companies, services companies, and academia. Go to the DWLS website to read the abstracts and for non-member registration information. Here is the list of speakers and topics. We hope to see you there!
- Ridvan Akkurt (Schlumberger)
A Machine Learning Based Automated System for Well Log Editing
- Richard Batsell (Rice University)
Successful Multivariate Modeling of Production from Oil and Gas Wells Enabling the Testing of Significant Managerial Questions
- Reinaldo Michelena (SeisPetro)
Petrophysical Multimineral Analysis Using a Genetic Algorithm: Applications to unconventional reservoirs
- Hani Elshahawi (Shell)
Machine Learning for Improved Directional Drilling
- Siddharth Misra (University of OK)
Machine Learning Applications in Reservoir Characterization
- Matt Belobraydic (Schlumberger)
Geology at the Crossroads of the Future
- Kim McLean (Emerson/Paradigm)
Geosteering an Unconventional Shale Lithozone with Confidence
- Richard Cao (Shell)
Integrated stochastic workflow for optimum well spacing with data analytics, pilots, geomechanical-reservoir modeling, and economic analysis
- Ishank Gupta (University of OK)
Rock Typing in Organic Shales: Barnett, Eagle Ford, Woodford and Wolfcamp
- Zoya Heidari (University of Texas at Austin)
Automatic Production- and Fabric-Oriented Rock Classification and Reservoir Evaluation in Organic-Rich Mudrocks through Integration of Multi-Scale and Multi-Physics Formation Data
If you have any questions please contact me.
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Calendar of Events
Click the calendar to the right to view events on the web.
Other Important Events
2019 SPWLA Annual Symposium, June 16-19, 2019 (The Woodlands, TX)
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DWLS Sponsors
Click here to view the sponsors on the website, or click on any image to contact a sponsor.
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Chapter Statistics
Statistic
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This Year
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3-Year Average
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| # of Active members * |
269 |
376 |
| # that are New members |
17 |
5 |
| # that are Students * |
2 |
10 |
| # that are Lifetime Members * |
257 |
297 |
| September luncheon meeting attendance |
44 |
57 |
| October luncheon meeting attendance |
29 |
62 |
| November luncheon meeting attendance |
43 |
55 |
| Holiday party attendance |
35 |
37 |
| January luncheon meeting attendance |
73 |
67 |
| February luncheon meeting attendance |
72 |
60 |
| March luncheon meeting attendance |
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45 |
| April luncheon meeting attendance |
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47 |
| May luncheon meeting attendance |
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51 |
* Note that we did a thorough cleanup of bad email addresses that resulted in some of our members being removed until they can be tracked down again. So this year's membership numbers are going to be a bit lower.
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The DWLS Newsletter is published monthly September through June by the Denver Well Logging Society. For information on membership or advertising, contact the editor. For other inquiries, contact a member of the Board of Directors.
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