Sedimentology and Reservoir characterization of Pirkoh Formation in well-1 Guddu E.L Sindh, Pakistan

  • Shaukat Ali Khan OGDCL
  • Sohail Hafeez OGDCL
Keywords: pirkoh formation, sedimentology, pakistan, stratigraphy, reservoir


Sedimentology and reservoir characteristics of Pirkoh Formation of Middle Eocene have been carried out in well -1 of Guddu E.L. by studying the two cores and well cuttings samples.  Pirkoh Formation was the primary objective reservoir in this well. It consist of entirely limestone penetrated in well with thickness of 102m. Two cores were cut from this formation (590-599m, 625-634m) and also incorporated in this study. The sedimentological investigation of cores and well cuttings of Pirkoh Formation revealed that it is mainly Wackestone-Packstone facie with larger benthics Forams (LBF) assemblages, consist of Discocyclina and Nummulite sp. in abundance. The Discocyclinoids Wackestone-Packestone facie along with micrite groundmass suggests that it was deposited over middle ramp settings. The presence of Discocyclina and Nummulites along with bioclasts of same microfossil suggests deposition under relatively high energy conditions over the ramp. The paleoecological attributes of Discocyclina and Nummulites also confer same environments. Micrite is the major ground mass matrix in the petrographic analysis which suggests relatively deep environment for its deposition most probably in Middle ramp settings.


Abbas G., 1999. Microfacies, depositional environments, diagenesis and porosity development in Limestone horizons of Kirthar Formation (Middle-Late Eocene) in frontal parts of Sulaiman fold belt and adjoining areas, Pakistan. Unpublished PhD Thesis submitted to University of Punjab, Pakistan 1-112.
Afzal J, Asrar MK, Naseer, AS., 1997. Biostratigraphy of the Kirthar Formation (Middle to Late Eocene), Sulaiman Basin, Pakistan. Pakistan Journal of Hydrocarbon Research 9, 15-33.
Ahsan N, Akhtar S, Chaudhry MN., 1993. Preliminary interpretation of the depositional environment based on microfacies analysis of Pirkoh limestone and marl member, Dhar, Taunsa, Pakistan Journal of Geology 1 & 2, 86-96.
Anketell JM, Mriheel IY., 2000. Depositional environment and diagenesis of the Eocene Jdeir Formation, Gabes-Tripoli Basin, Western Offshore, Libya. Journal of Petroleum Geology 23(4), 425-447.
Allmendinger, R.W, 1988. Stereonet p.3.75, Banks, C.J., and Warburton, J.1986, “Passive-roof” duplex geometry in the frontal structures of the Kirthar and Sulaiman mountain belts Pakistan, Journal of Structural Geology.
Butt A., 1981. Depositional environments of the Upper Cretaceous rocks in the northern part of the Eastern Alps. Cushman Foundation for Foraminiferal Research 20, 1-121.r
Cotter & Gill (1952) Thrust Tectonics, Thin skinned or thick skinned and the continuation of thrust to deep crust by M.P Coward, Deptt. Of Earth Sciences, Leads University, Leads LS29JT, U.K 1983.
Dunham RJ., 1962. Classification of carbonate rocks according to depositional texture. In W. E. Ham, (ed) Classification of Carbonate Rocks. American Association Petroleum Geologists Memoirs 1, 108-121.
Farah, A., M.A. Mirza. A.A Ahmad and M. A. Butt., 1977. Gravity field of the buried shield in the Punjab plain, Pakistan: Geological Society of America Bulletin, v.88. Fatmi, A. N., 1973. Lithostratigraphic units of the Kohat - Potwar province. Indus basin, Pakistan. Geological Survey of Pakistan: Memoirs, 10.
Flügel E. 2004. Microfacies of Carbonate Rocks; Analysis, interpretation and application. Springer Verlage, Berline p.1-976.
Hunting Survey Corporation, 1960. Reconnaissance Geology of Part of West Pakistan: Toronto, Govt. of Canada, 550p.
Humayon, M.,Lillie, R.J., and Lawrence, R.D., 1991. Structural interpretation of the eastern Sulaiman foldbelt and fore deep, Pakistan: Tectonics.
Hunting Survey Corporation, Ltd., 1961. Reconnaissance geology of part of West Pakistan, Toronto, Ontario, Canada, Colombo Plan Cooperative Project.
I.B. Qadri (PPL), Geology of Hydrocarbon accumulation in Pakistan, 6th offshore Southeast Asia conference Singapore.
Jadoon, I.A.K., Lawrence, R.D., and Lillie, R.J., 1992. Balanced and retro deformed geological cross-section from the frontal Sulaiman lobe, Pakistan: Duplex development in thick strata along the western margin of the Indian plate, in McClay, K.,ed Thrust tectonics: London.
Jadoon, I.A.K., Lawrence, R.D.,1993. Evolution of foreland structures, an example from the Sulaiman thrust lobe of Pakistan, SW of the Himalayas, in Treloar, P.M., and Searle, M., eds., Himalayan tectonics: Geological Society of London Special Publication.
Jadoon, I.A.K., Lawrence, R.D., and Lillie, R.J., 1994. Seismic data, geometry, evolution, and shortening in the active Sulaiman fold-and-thrust belt of Pakistan, southwest of the Himalayas: American Association of Petroleum Geologists Bulletin.
Luterbacher H., 1998. Sequence Stratigraphy and the Limitations of Biostratigraphy in the Marine Paleogene Strata of the Tremp Basin (Central Part of the Southern Pyrenean Foreland Basins, Spain). SEPM Society for Sedimentary Geology, special Publications 60, 303-309.
M. A. Khan and Hilal A. Raza., 1986. The role of geothermal gradients in hydrocarbon exploration in Pakistan, Journal of Petroleum Geology, 9, 3, pp. 245-258.
Racey A., 1994. Biostratigraphy and palaeobiogeographic significance of Tertiary nummulitids (foraminifera) from northern Oman. Micropaleontology and hydrocarbon exploration in the Middle East. Chapman and Hall, London p. 343-370.
Quadri, V., and Shuaib, M., 1986. Hydrocarbon prospects of Southern Indus Basin, Pakistan: American Association of Petroleum Geologists Bulletin.
Wilson JL., 1975. Carbonate Facies in Geologic History Springer-Verlag. New York p. 1-471.