CWLS12SC Shale Gas Petrophysics: Using Clustering and Mineral Based Interpretation: The Easy Way
The clustering method allows the shale gas zones to be defined as different rock types. Then one just selects the mineralogy for each rock type, tests the selection by reconstructing the neutron and comparing it to the recorded neutron. If core XRD is available, a method is described to check the core accuracy, and the mineral selection can then be checked against core.
This is a straight-forward "EASY" method for accurate shale gas analysis.
Data sets are requested about one month prior to the course day from each participant. One of these data sets will be selected and sent to each course participant. With supplied cluster/mineral software, the course participants will, as a group, use the supplied software to characterize the rock groups as lithology and then as minerals. The mineral attributes are used to solve for Sw, porosity and permeability which can then be compared to core values.
Data sets should have the following data, in addition to being released for distribution to course participants:
1) logs should include: triple combo, compressional and shear, nuclear spectroscopy (example is an Elemental Capture Spectroscopy (ECS); other brands of nuclear spectroscopy are acceptable). Good borehole is desired, of course, but if not possible, correction methods for the density will be discussed and implemented. We will work with whatever is supplied.
2) core or cuttings mineral analysis (quantitative XRD, quantitative FTIR etc)
3) core porosity, perm and Sw.
4) relationship of TOC and kerogen, as well as adsorbed gas (Langmuir volume and pressure vs. TOC, Isotherms)
Items 2, 3, 4 are nice to have to check one's interpretation for validity. However, if they are not available, we can work with what is available.
In the event that no data sets are releasable, one will be supplied in advance of the course for personal interpretation, to all course participants. That way, the content of the logs will not be completely new to the course participants and they can concentrate on the methodology presented in the course.
We plan to work as a team to get the best possible solution for the data set supplied, in the time allotted. Then you can return to your work and apply the same methods to your wells.
This is considered as an Advanced course but participants at all levels can benefit from the team exercise.
Location: Weatherford, 1200 - 333 5th Ave SW
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R. V. (Bob) Everett, P.Eng. is a Consulting Petrophysicist and Professional Engineer with over 40 years experience in petrophysical analysis. He is a specialist in the integration of Neutron Spectroscopy having spent some early years at Schlumberger-Doll Research working on shaly sand analysis. Bob has also worked as a consultant for Texaco, Unocal, and Z&S/Dresser Atlas/Baker Hughes, and the University of Texas at Austin on a GRI Tight Gas Sand project. Some of the many plays he has worked on are offshore West Africa carbonates, West Texas Carbonates, Alberta Devonian Reefs, and Alberta shallow gas Sands as well as Shale Gas plays. He is particularly interested in the mineralogical and chemical aspects of petrophysics involving shaly sands, tight gas sands and shale gas reservoirs and has been directly involved with the development of mineralogical and geochemical logging tools. He has a BASc in Mechanical Engineering from the University of British Columbia.
