Identification of Hydrocarbon Potential of Talhar Shale: Member of Lower Goru Formation Using Well Logs Derived Parameters, Southern Lower Indus Basin, Pakistan

Abstract

Using well logs data only, the evaluation of shale gas hydrocarbon potential of Talhar Shale Member of Lower Goru Formation has been a challenge in Southern Lower Indus Basin in Pakistan. Well logs data analysis is helpful to evaluate the gas potential of source shale rocks. We introduced and applied empirical and graphical method to fulfil this task and derived geochemical parameters from well logs data. The method mentioned is cheap and fast. Talhar Shale has kerogen type III and type II which are montmorillonite clay and have potential to produce oil and gas. Talhar Shale has better sorption property. Empirical formulas are used to derive parameters, using well logs of porosity, density and uranium. Porosity and volume of kerogen, calculated from density log, give average values of 11.8% and 11.4%. Average value of level of maturity index (LMI) derived from log is 0.54, which indicates that it is at the early stage of maturity. Vitrinite reflectance is between 0.5%–0.55% as calculated by graphical method and empirical formula. Talhar Shale is at onset of oil generation, with main products of oil and gas. It is a good potential source in the study area.

Keywords

Talhar Shale / kerogen type / sorption property / thermal maturity / vitrinite reflectance (Ro) / Southern Lower Indus Basin

References

[1] Ahmad A. Source Rock Potential of Lower Goru in Well Bobi-4 Lower Indus Basin, Pakistan. Pakistan Journal of Hydrocarbon Research, 1997, 9: 83-89.

[2] Alyousuf T., Algharbi W., Algeer R., . Source Rock Characterization of the Hanifa and Tuwaiq Mountain Formations in the Arabian Basin Based on Rock-Eval Pyrolysis and the Modified Delta Log R Method, 2011

[3] Ariketi R. Estimation of Level of Organic Maturity (LOM) and Total Organic Carbon (TOC) in Absence of Geochemical Data by Using Resistivity and Density Logs––Example from Cambay Shale, Tarapur Area, Cambay Basin, India. Jour. Indian Association of Sedimentologists, 2011, 30(1): 55-63.

[4] Godec M., Koperna G., Petrusak R., . Potential for Enhanced Gas Recovery and CO₂ Storage in the Marcellus Shale in the Eastern United States. International Journal of Coal Geology, 2013, 118: 95-104.

[5] GOP Government of Pakistan Petroleum Exploration Opportunities, 2012.

[6] Haider B. A., Aizad T., Ayaz S. A., . A Comprehensive Shale Gas Exploitation Sequence for Pakistan and Other Emerging Shale Plays, 2012

[7] Hanif M., Hart M. B., Grimes S. T., . Integrated Stratigraphy and Palaeoenvironment of the P/E Boundary Interval, Rakhi Nala Section, Indus Basin (Pakistan). Arabian Journal of Geosciences, 2014, 7(1): 323-339.

[8] HDIP Hydrocarbon Development Institute of Pakistan Pakistan Energy Yearbook 2012, 2012.

[9] Hill R. J., Zhang E. T., Katz B. J., . Modeling of Gas Generation from the Barnett Shale, Fort Worth Basin, Texas. AAPG Bulletin, 2007, 91(4): 501-521.

[10] Holditch S. Unconventional Oil and Gas Go for the Source, Presentation, 2011.

[11] Hood A., Gutjahr C., Heacock R. Organic Metamorphism and the Generation of Petroleum. AAPG Bulletin, 1975, 59: 986-996.

[12] Kadri I. B. Petroleum Geology of Pakistan, 1995.

[13] Khattak F. G., Shafeeq M., Ali S. M. Regional Trends in Porosity and Permeability of Reservoir Horizons of Lower Goru Formation, Lower Indus Basin, Pakistan. Pakistan Journal of Hydrocarbon Research, 1999, 11: 37-50.

[14] Labani M. M., Rezaee R. Thermal Maturity Estimation of Gas Shale Layers from Conventional Well Log Data: A Case Study from Kockatea Shale and Carynginia Formation of Perth Basin Australia, 2012.

[15] Lecompte B., Hursan G. Quantifying Source Rock Maturity from Logs: How to Get More than TOC from Delta Log R. Behavioural Brain Research, 2010, 193(1): 1-16.

[16] Magara K. Compaction and Fluid Migration: Practical Petroleum Geology, 1978.

[17] Machel H. G., Krouse H. R., Sassen R. Products and Distinguishing Criteria of Bacterial and Thermochemical Sulfate Reduction. Applied Geochemistry, 1995, 10(4): 373-389.

[18] Passey Q. R., Creaney S., Kulla J., . A Practical Model for Organic Richness from Porosity and Resistivity Logs. AAPG Bulletin, 1990, 74: 1777-1794.

[19] Passey Q. R., Bohacs K., Esch W. L., . From Oil-Prone Source Rock to Gas-Producing Shale Reservoir-Geologic and Petrophysical Characterization of Unconventional Shale-Gas Reservoirs, 2010

[20] Prasad M. Mapping Impedance Microstructures in Rocks with Acoustic Microscopy. The Leading Edge, 2001, 20(2): 172-179.

[21] Quadri V. N., Shuaib S. M. Hydrocarbon Prospects of Southern Indus Basin, Pakistan. AAPG Bulletin, 1986, 70: 730-747.

[22] Robison C. R., Smith M. A., Royle R. A. Organic Facies in Cretaceous and Jurassic Hydrocarbon Source Rocks, Southern Indus Basin, Pakistan. International Journal of Coal Geology, 1999, 39(1/2/3): 205-225.

[23] Schmoker J. W. Determination of Organic Content of Appalachian Devonian Shales from Formation-Density Logs: Geologic Notes. AAPG Bulletin, 1979, 63: 1504-1509.

[24] Schmoker J. W., Hester T. C. Organic Carbon in Bakken Formation, United States Portion of Williston Basin. AAPG Bulletin, 1983, 67: 2165-2174.

[25] Shazly T., Ramadan M., El-Sawy M. Application of Well Logs Analysis to Identify the Source Rock Capabilities of Rudeis and Kareem Formations in Rudeis Field, Gulf of Suez, Egypt. Journal of Applied Sciences Research, 2013, 9(9): 5419-5435.

[26] Smith M. A., Karl W., Schwab K. K. B. Organic Facies Analysis of Cretaceous Petroleum Source Rocks, Southern Indus Basin, Pakistan. AAPG Bulletin, 1992, 76: 1126-1127.

[27] Vernik L., Liu X. Z. Velocity Anisotropy in Shales: A Petrophysical Study. Geophysics, 1997, 62(2): 521-532.

[28] Zhang T. W., Ellis G. S., Ruppel S. C., . Effect of Organic-Matter Type and Thermal Maturity on Methane Adsorption in Shale-Gas Systems. Organic Geochemistry, 2012, 47(25): 120-131.

[29] Zhang T., Ellis G. E., Ruppel S. C., . Effect of Organic Matter Properties Clay Mineral Type and Thermal Maturity on Gas Adsorption in Organic-Rich Shale Systems. Unconventional Resources Technology Conference, 2013, 72(2): 1996-2001.