SEQUENCE STRATIGRAPHY, DEPOSITIONAL ENVIRONMENTS AND RESERVOIR CHARACTERIZATION OF SA'DI FORMATION IN EAST BAGHDAD AND HALFIYA OILFIELDS
Turonian-Early Campanian sediments (AP 9) are restricted to area of Mesopotamian and the Jezira Subzone. It was deposited in relatively narrow seaway that occupies the area of the salman, Mesopotamian, Foothill and high folded zones. The lower part of this megasequence is revealed by the Khasib, Tanuma, Sa'di and Kometan formations. This study is based on samples from two wells; the first is in East Baghdad field, Sa'di Formation about 146.7 m thick, and the second is in Halfiya field, Formation about 100 m thick. The Sa'di Formation consists of two members, they are Upper member, which is composed of bitty bioclastic, planktonic foraminiferal chalky limestone, with some calsicphers, and lower member of the formation, which consists of homogenous, rich planktonic foraminiferal chalky limestone,in additionto small amounts of benthonic foraminifera and bioclastic grains. The Sa'di Formation is overlain the Tanuma Formation, and underlain the Hartha Formation. The Sa’di Formations is composed of four main facies subscribe as S1, S2, S3 and S4. The facies S2 appeared in the upper member, whereas the others are spread in the lower member, which were deposited in deep shelf margin environment. The Gamma Ray log is used to calculate the volume of shale of Sa'di Formation after removing the shale effect due to the porosity equation correction. Depending on the result of porosity values for both wells, the Sa'di Formation successions have been divided into members, they are; the lower and upper members. The lower member separated into two zones, the first have poor to fair porosity, and the second have fair to very good porosity. Whereas the upper member divided into two zones and the porosity wobble between good to very good.