Kurdistan
Location: Kurdistan (northern Iraq)
Area: 492 km2
Sterling Equity: 53.33% (Operator)
Partners: Addax 26.67%, KNOC 20%
During 2009 preparations were made to drill the first exploration well on the Sangaw North block. Detailed well planning
and design along with the procurement of well services and goods were progressed in parallel with construction of the
well site. Heavy rain in the area during November and December delayed the completion of the civil works. Drilling
commenced on 1 February 2010 and is expected to take 180 days.
The well is being drilled using the 2,000 horse-power Sakson PR-4 rig to a planned total depth of 3,660m targeting
several Cretaceous and Jurassic aged reservoirs. The well design gives the option to drill deeper to a total depth of
4,160m to test deeper Jurassic aged reservoirs. The decision to drill this additional section will be taken based upon the
preliminary drilling results.
Having completed the acquisition of 325km of 2D seismic data during 2008, a number of specialist processing
techniques were undertaken in order to achieve the best possible seismic image of the sub-surface structure. The
interpretation and mapping of this seismic data confirmed the presence of a very large subsurface structure, coincident
with the outcropping surface anticline. The integration of regional and locally acquired field geological data with the
results of the seismic interpretation have been combined to advance the Sangaw North lead to a drillable prospect.
The primary reservoir target is the Upper Cretaceous carbonates of the Shiranish, Kometan and Qamchuqa formations.
These intervals are proven, hydrocarbon bearing and productive in all directions including the Taq Taq and Chemchemal
fields. The presence of surface oil seeps on the Sangaw North structure, geochemically akin to the oil in adjacent fields
such as Kirkuk and Taq Taq, provides considerable encouragement for the presence of subsurface hydrocarbon
entrapment at Sangaw North. An independent report completed by RISC estimates best estimate gross prospective
resources for the Upper Cretaceous reservoir of 804 mmbbl with a 27% chance of success. RISC considers that
condensate and gas are at least as likely to be discovered as oil. Historical success rates for recent exploration wells drilled
in the Kurdistan region are around 50%.
Secondary reservoir potential is also being targeted in a number of Jurassic objectives. Underexplored due to the impact
of Tertiary overburden on drill depths, the Jurassic is the emerging play in the Zagros Fold Belt. The thin Tertiary cover
(i.e. thickness) on the Sangaw North structure and the drilling capacity of the rig being used make the Jurassic an
achievable deeper target.
Continued exploration success by other operators confirms the highly prospective nature of the Kurdistan region. In May
2009, Heritage reported an oil discovery at Miran West, 40km north of Sangaw North-1. Further north Gulf Keystone
reported an oil discovery at Shaikan in August 2009 in the same Cretaceous and Jurassic reservoirs being targeted by
the Sangaw North-1 well.
