Petrography, mineralogy and clay minerals, An attempt to reservoir characterization of Shurjeh reservoir, Gonbadli Gas Field
Subject Areas : Petroleum Reservoir GeologyAlireza Bashari 1 , Bijhan Mostaghel 2
1 - Research Institute of Petroleum Industry (RIPI)
2 - Head of Oil and Gas Exploration and Production department, Petro Kaveh Group, Tehran, Iran
Keywords: Gonbadli Gas field, shurjeh, Petrography clay mineralogy, Petrophysics,
Abstract :
Petrography and clay mineralogical study on DII, DI memebers of shurjeh gas reservoir ( sand stones) , and upper member of DII shows , presence of different type of minerals, as well as clay minerals , such as calcite, gluconate, Pyrite, Iron oxide, interbedd with silty & clay layers. Petrography studies along with XRD, XRF, EDX, SEM on the present samples, indicates presence of, kaolinite , illite chlorite and expandable clay minerals. Expandable clay comprise smectite and mixed layer or interstratified Illite / Smectite ( I/S) .Clay minerals have a tendency to change permeability of the rock, and hinder the passage of fluids. Kolinite may also cause varying degrees of impaired permability on contct with fresh water.The presence of interstitial clay drastically increase microprosity whilst at the same time reducing effective prosity. Petrography study shows , the mineralogical composition of reservoir rock comprised, Sublitharenites , using nomenclature of Folk, 1980., in general , 75% Quartz, 6% Feldspar and 15% Rock Fragments. Presence of different clay minerals in pore networks may have a significant impact on petrophysical properties of reservoir and hence affect reservoir productivity.