THE STUDY OF MINERALOGICAL AND MICROFACIES ANALYSIS SHIRANISH FORMATION WELL (KH-6) ANSAB AREA IN SOUTHERN IRAQ

Abstract

The study of Shiranish Formation rocks in southern part of Iraq at Ansab area well (KH-6)
were carried out. The formation is tongued with tayarat formation, which bounded from top
and bottom, the upper tongue at thickness 49m. and tongued at depth (476-525m.) the lower
tongue at thickness 4m. tongued at (541-537m.).
The rocks of this formation were divided into three sedimentary microfacies:
1- Dolomitized formininferal Wackestone facies.
2- Dolomitized formininferal Mudstone facies.
3- Dolostone facies.
34 slides were investigated depending on mineralogical, compositional and biological
processes and compared diagenesis which reflect open marine shelf at lower part of formation
(F.Z.2) (S.M.F.8), but at the top represent deep shelf margin environment.
The most important diagenesis is neomorphism and spary calcite cement deposits within
fossils (intragranular) with late dolomitie stage special in dolostone facies (third facies).