The Oklahoma City Chapter of the SPWLA has its technical luncheon meetings on the second Tuesday of each month at 11:30 am to 1:00 pm (September through May). The meetings are held at the Petroleum Club of Oklahoma City; 100 North Broadway Oklahoma City, OK 73102 (on the 35th floor of the Chase Building – Downtown OKC).
Annual dues for the OKC SPWLA Chapter are $15. Checks can be made payable to: OKC SPWLA
SPWLA - Oklahoma City Chapter P.O. Box 2741 Oklahoma City, OK 73101
The OKC SPWLA will have its next technical lunch meeting on Tuesday, May 14th, 2013. The meeting will be on the 35th floor of the Chase Building – Petroleum Club – Downtown OKC at 11:30 am. Lunch for OKC-SPWLA Chapter members with reservations $20; non-members will be charged $25.
For reservations call Nora Fitzpatrick (Baker Hughes) 917-6791
Review and Comparison of Three Different Gas Shale Interpretation Approaches
John Quirein, Halliburton
This paper reviews and compares three recently published approaches for simplicity, validity, and parameter sensitivity. Two of the approaches are based on a deterministic model; the third approach uses a response equation approach in which models can be defined by means of tool response and interpretation constraint equations. The first approach assumes that the weight fraction total organic carbon (TOC) is available from an external source, the rock grain density is available, and the total water saturation is constant. This approach enables the use of a single equation based upon the bulk density log to solve for total porosity from which, with the assumption of constant water saturation, the gas filled porosity can be obtained. The second approach assumes that the formation consists of two constituents: porous mineral matrix and porous kerogen. It makes use of the fact that in gas shales, kerogen generally contains oil-wet porosity, so that a constant kerogen porosity, completely gas saturated is imposed. By using the sonic and density logs with an assumed known rock grain density and by assuming that the porous mineral matrix gas saturation is a constant, the volumes of porous mineral matrix, porous mineral kerogen, and porous mineral porosity can be obtained. The assumption of a constant porous mineral gas saturation can be relaxed by iteratively using the resistivity log to update the assumed value of the hydrocarbon saturation.
This paper shows that either of these two models, 1 and 2, can be equivalently obtained by using a response equation based statistical optimization technique. This technique requires only some simple constraints, such as constant kerogen porosity or constant gas saturation. Moreover, the constant saturation assumptions can be easily removed and, with or without wireline geochemical data, TOC, or x-ray diffraction (XRD) mineral data, it is possible to calibrate to core grain density and gas filled porosity.
The results of all three approaches are presented for several Haynesville gas shale wells. The explicit models of approaches 1 and 2, such as constant kerogen porosity or constant total water saturation, are tested for consistency with core data. Although approach 2 suggests using TOC to establish a correlation with pyrite to obtain an improved prediction of grain density, the paper demonstrates that geochemical logs generally provide a more robust prediction of kerogen because they measure sulfur directly. Finally, the results of a parameter sensitivity study are presented.
John Quirein is the petrophysics team leader in the Halliburton Formation Evaluation Technology group, focusing in interpretation and software development with a recent emphasis on gas shale petrophysics, geochemical log interpretation, and multi-mineral solvers. He received a PhD degree from the University of Houston, and has worked for 10 years at Schlumberger, 12 years at Mobil, and the last 12 years at Halliburton. Quirein is a past SPWLA president and is currently a member of the SPWLA Foundation.
The Oklahoma City SPWLA Chapter officers are as follows:
333 W. SheridanOklahoma City, Oklahoma 73102
VP Technology / Education
vacant for 2011-2013
R. E. Schneider
300 United Fndrs Blvd. #128
Oklahoma City, Oklahoma 73112
Thmp925 at aol.com
|Secretary / Treasurer
GMX Resources9400 N. Broadway Suite 600Oklahoma City, Oklahoma 73114CMauldin@gmxresources.com