Saudi Arabia, long known for its enormous structures, very high rate and relatively shallow wells is continuing its extensive conventional exploration activity. It is also looking at "unconventional?? resources, especially tight gas reservoirs.
The primary focus of the tight gas effort within Saudi Aramco has been in trying to understand the hydrocarbon resources, reservoired in the lower Paleozoic siliciclastic succession. This succession is dominantly a pile of sandstones, several thousand feet thick. In the middle is the Silurian aged Qusaiba Shale. The nature of the Lower Paleozoic succession varies considerably across Saudi Arabia, from outcrops to 20,000 ft+ depths, and with reservoir qualities that range from conventional to distinctly tight.
Exploration activity in Southern Saudi Arabia over the past four years has more than doubled the number of lower Paleozoic penetrations in the South Ghawar and Rub'al-Khali areas. This activity has resulted in a number of key developments including:
Confirmation that the pre-Qusaiba sandstones of the Sarah and Qasim (Late Ordovician) contain significant untapped tight gas resources.
Identification of entirely new play concepts in Saudi Arabia, some of which are discussed in this paper.
Increased understanding of the complexity and opportunities of the Lower Paleozoic succession in Southern Saudi Arabia.
Current conventional exploration activity in Northwest Saudi Arabia is acquiring additional data to allow the known tight gas resource in the region to be better quantified. Due to the shallower depths of the tight gas resource and local demand for gas, Northwest Saudi Arabia is seen as the one of the priority areas for Saudi Aramco's tight gas efforts.
Saudi Aramco sees the potential of using local tight gas resources in conjunction with conventional resources to underpin regional development. Saudi Aramco has thus initiated activities that will enable it to commercialize these resources for the benefit of the Kingdom.