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Geology/Please help me


my question are:
firstly; the role of calcareous non-fossils and palynomophy in exploration of hydrocarbon or petroleum exploration.

secondly; the role of geochemical survey and geological survey in oil gas exploration.



Please contact an Expert in Biostratigraphy for your first question.

Geochemical surveys are undertaken to establish the quality, maturity and the generating potential of a source rock. Shale is the main source rock wherein the preservation of the organic content (TOC) is most likely to happen, as it is generally deposited in deeper anoxic (oxygen free) environments. The subsurface samples from oil wells, and surface samples from the outcrops are collected and analysed. It is important that the samples collected from the outcrops must be taken from below the weathering surface. The data helps in establishing the kind of hydrocarbons that can be expected, and the overall endowment of a geological basin. Sometimes the lighter gas molecules, leaking from a subsurface trap, reach the ground level. In such areas the tone of the surface sediments may change that could be detected on space images; and it gives a lead to collect the surface soil samples from that specific area to confirm the reason for the change in the tone. It could be due to mineralogy of the soil, weathering of an economical deposit exposed at the surface etc, or due to the presence of lighter hydrocarbons.

Geological surveys are conducted to establish the stratigraphy, thickness of the formations and their structural style and trend as seen on the surface. The information helps in establishing the subsurface geology and the structural geometry; the present surface itself was the subsurface in the geological past, anyway!The surface mapping helps greatly in interpreting the seismic sections. Sometimes the stratigraphy and dip of the strata is mapped along seismic dip lines to match the surface contacts with the subsurface reflectors recorded on the seismic line. The thicknesses, thus established are the basis of a well prognosis and the TD of a well.


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Nusrat Kamal Siddiqui (Mr)


I am a petroleum exploration geologist with about 40+ years of diversified experience. I can answer questions on stratigraphy, log interpretation, field studies based on set of logs and core results, general geology etc. Can provide guidance for career planning in earth sciences. Can not help in questions about hard rocks, igneous petrology & mineralogy, sequence stratigraphy and seismic.


Petroleum Exploration - field geology, stratigraphy, prospect generation, interpretation of satellite imagery (visual), log interpretation.

Retired in May, 2006 as Senior Manager Exploration from Pakistan Petroleum Limited after serving 26 years. Since then continuing in active service with petroleum exploration companies.A cumulative experience of about 40 years covers 30 years in petroleum exploration, 5 years hydrogeology experience in Libya, and about 5 years of dam geology in Pakistan.

-AAPG Bulletin (Vol.88, July, 2004); paper on Sui Main Limestone (Eocene), a prolific gas reservoir in Pakistan. -Have presented papers on diversified topics ranging from spirituality, flood control, remote sensing and off course geology in France, Nepal, Bangladesh, Sri Lanka, UAE, Kashmir, India and Pakistan that have been published in respective Special Proceedings. -ONGC Bulletin(India) Vol. 44, Number 2, December, 2009; Chapter 19.A & 19.B on basin architecture and stratigraphy of Pakistan, p.402-474.

BSc Honours in Geology and Master of Science in Petroleum and Structural Geology. PGD from ITC, The Netherlands.

Awards and Honors
-Remained Active Member of AAPG from 1990-2006; founding member of PAPG (a local affiliate of AAPG). -Life member of SEGMITE & AGID, and Senior Editor of SEGMITE magazine. -Member of the Board of Studies, i. Department of Petroleum & Gas Engineering (BUITMS, Quetta), and ii. Geology Department, Sindh University, Jamshoro. -Member of Stratigraphic Committee of Pakistan. -Represented Mining Journal, UK in Pakistan till 2007. -Chairman of Annual Technical Conference (ATC)& Oil Show, an SPE/PAPG annual event, in 2003. -Chairman Technical Committee (ATC, 2002).

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