Fitian R. Al-Rawi, Thamer K. Al-Ameri & Salih M. Awadh
الملخص الانجليزي
Findings of the oil source affinity for oil sample
collected from shallow borehole already drilled for ground
water purposes at the Sakran area, NE Haditha city, western
Iraq, is performed in this study by biomarker studies with
addition to the analysis of gravity map. Petroleum geochemistry
study is carried out on oil sample. The terpane and
sterane biomarker distributions, as well as the stable isotope
values, are used for determining the validity of oil to correlate
its source. The results showed that the oil belongs to the
Jurassic age, with high sulfur content (2.75 %) and value of
C28/C29 up to 0.75. The tricyclic terpanes values as well as
hopanes indicated a source rock affinity of carbonates,
whereas the pristine/phytane ratio indicated marine algal
source of kerogen type II. All these information could
confirm that the source rock affinity was the Sargelu
Formation (Jurassic), in which their age’s equivalent to the
source in East Baghdad Oil Field and Tikrit Oil Field, with a
difference from the oil family near the Akkas field, located
to the west of the area. Chemical analyses of water sample
collected from the borehole showed the following results:
TDS=12,700 mg/l, EC=215,900 μs/cm, pH=6.8, DO=
28 mg/l, and temperature=24 °C. Hydrochemical functions
such as rNa/rCl (<1), (rNa–rCl)/rSO4 (<0) and rSO4/rCl (<1)
indicate that the water is of marine origin, partially mixed
with meteoric water. Analysis of the gravity map revealed
two anomalous areas; the western one represents large
anomaly with EW trend similar to the Anah graben to the
north. The second one consists of many anomalies trending
N–NW direction. The main local anomaly is identical with
the seeps from the drilled borehole covering large area. The
boundaries and trends of the main geological structures have
been defined by gradient analysis procedure to the gravitydata. The closed gravity anomalies with their large extensions
reflect the importance of the results for further studies
and promising area for oil reservoirs.
صالح محمد عوض | Salih Muhammad Awadh | 11332