Abstract:
The Potwar Plateau of Pakistan is bounded by the Kala Chitta and Margalla Hill ranges to the north and upthrusted Salt Range to the south. The Jhelum Fault and the Indus River confine the Potwar Plateau to the east and west respectively. The plateau is mostly covered by the molasse sediments of the Miocene to Pleistocene in age and is traversed by the Soan River from northeasterly to southwesterly direction. The Potwar Plateau has long been known as a major oil and gas producing region of Pakistan. The first discovery in Pakistan was made in the Potwar Plateau at Khaur in 1915. The Potwar Plateau has been one of the most difficult places in Pakistan to drill. The oil and gas play in the Potwar Plateau, at times, occurs even deeper than 15000 feet below the molasses. These sediments that were deposited as a very thick prograding clastic wedge over the oil and gas play are abnormally pressured with gradients close to lithostatic. Kadri (1991), considered under compaction to be the likely cause of over pressuring in molasse. These abnormal pressures, which besides other factors, are considered to be a consequence of rapid sedimentation leading to under compaction, result in enormous drilling costs and time. At times these abnormal pressures have also resulted in the abandonment of wells without reaching the target depth.
Page(s):
25-40
DOI:
DOI not available
Published:
Journal: Proceedings of 5th Pakistan Geological Congress , Volume: 0, Issue: 0, Year: 2007