China Petroleum Exploration ›› 2016, Vol. 21 ›› Issue (3): 74-82.

• PETROLEUM GEOLOGY • Previous Articles     Next Articles

Forming conditions of Pengzhou large gas field of Leikoupo Formation in Longmenshan piedmont tectonic belt, western Sichuan Basin

Li Shubing, Xu Guoming, Song Xiaobo   

  1. Sinopec Southwest Oil & Gas Company
  • Online:2016-05-15 Published:2016-05-15

Abstract: Through efforts in eight years since 2006, a great gas exploration discovery was made in the Pengzhou Leikoupo Formation of the Longmenshan piedmont tectonic belt, western Sichuan Basin, which contributed a new large marine gas field - Pengzhou gas field. Study indicates that the Pengzhou Leikoupo Formation reservoir presents as there is a dissolution-pore type dolomite reservoir under a structural setting of large positive uplift belt, with features of a big thickness, a wide distribution, better lateral continuities, good physical properties, high gas-bearing potentials, and high productivities. The reservoir is suggested as a sour gas field with normal temperature, normal pressure and high sulfur content. It is concluded that the Pengzhou large gas field of Leikoupo Formation was formed under three major conditions. First, multiple source rocks supplied abundant hydrocarbons, providing a good material basis. Second, large-scale dolomite pore type reservoir existed in the 4th member of the Leikoupo Formation, providing sufficient storage spaces. Third, large positive uplift belt provided enough spaces for hydrocarbon accumulation. Meanwhile, it is pointed out that the Leikoupo Formation gas reservoir in the Longmenshan piedmont tectonic belt features high filling degree and great exploration potential.

Key words: western Sichuan Basin, Longmenshan piedmont tectonic belt, Leikoupo Formation, large gas field, forming condition