• Friday, June 12, 2015

    Importantance of minor occurrence or showings

     Importantance of minor occurrence or showings

    Importantance of minor occurrence or showings


    اهميه الاحداث السطحيه والاحداث التحت سطحيه

    Although not important for economical development minor occurrences are consider important because

    They indicate that some of the rocks in the area where they are found are possible oil source rock

    حيث توضح هذه الاحداث السطحيه والتحت سطحيه انواع الصخور الموجوده فى هذه المنقطه المراد حفرها ومن ثم يعطى انطباع عن مدى وجود واحتماليه وجود الصخر الذى يعتبر بمثابه الصخور المصدره للبترول

    They may indicate that economically important oil might have migrated from the rocks which contain these minor occurrences

    تعطى هذه الاحداث معلومات عن هجره البترول وسريانه بين الصخور عن طريق تحليل هذه الاحداث السطحيه

    They may indicate that they are on or near the edge of an important oil accumulation and thus these minor surface or subsurface occurrence may lead to amajor discovery nearby

    Surface Occurrences


    Seepages,Springs

    Importantance of minor occurrence or showings

    Seepages,springs,imperegnated deposits ,bitumenous lakes and oil shales are common features of surface occurrences

    petroleum as gas oil or liquid asphalt reaches the surface along fractures,faults,planes unconformities,joints,bedding plants or any connected porous opening in the rocks.spepages are mostly formed by the escape of petroleum in alarge quantities in the subsurface through these structural or erosional features


    mud volcanoes and mud flows

    Importantance of minor occurrence or showings

    Mud volcanoes is ahigh-pressure gas seepage the carries with it water,sands,fragments of rock,and occassionally oil

    Many mud volcanoes and mud flows occur south of the central range on the island of trindad

    Subsurface occurrences

    Underground or subsurface occurances of petroleum may be 

    :divided according to their size into

    Minor oil and gas showing 

    Oil and gas accumulations pools,fields,and provinces

    Minor oil and gas showing

    Some gas and oil are found in most wells drilled in sedimentary rocks many oil showings are on the borderline between commerical and non commericial to differentiate between them is one of the problems confronting every petroleum geologist concerned withe drilling wells .the oil and gas showings may be observed directly or by means of tests and logging methods


    Oil and Gas accumulation

    Commericial petroleum deposits are classified into pools,field and provinces


    Oil and Gas pools

    Importantance of minor occurrence or showings

    Pool is the simplest unit of commerical occurances of oil and gas accumulation

    Its defined as the boody of oil and gas or both occurring in aseparate reservoir and under asingle pressure

    Oil and Gas field


    the group of pools related to one single geologic feature either structural,stratigraphie or lithofacial are called afield

    Oil and Gas provinces

    Apetroleum provinces is aregion in which anumber of oil and gas pools and fields occure in the similar or related geological 
    environment