Oil & Gas Geology ›› 2014, Vol. 35 ›› Issue (2): 238-243.

Previous Articles     Next Articles

Upper limit and distribution of physical property of tight gas sandstones

Wang Pengyan1, Liu Fengxuan1, Ma Feng2, Yang Mian1, Lin Yikang3, Lu Chong4   

  1. 1. School of Earth Sciences, Northeast Petroleum University, Daqing, Heilongjiang 163318, China;
    2. Exploration and Production Research Institute, PetroChina, Beijing 100083, China;
    3. Exploration and Production Research Institute, PetroChina Qinghai Oilfield Company, Dunhuang, Gansu 736202, China;
    4. No.1 Oil Production Plant, PetroChina Qinghai Oilfield Company, Mangya, Qinghai 816499, China
  • Received:2013-08-10 Revised:2014-01-10 Online:2014-04-08 Published:2014-05-21

Abstract: The formation of tight gas is controlled by the low porosity and permeability of sandstone reservoirs.It has been recognized that the accumulation of pervasive low abundance tight gas is possible only when the porosity and permeability of reservoir is above a certain limit value.However,there are no widely accepted criteria for defining this limit value.Based on collection of the measured reservoir property of both domestic and international typical tight gas sands,we stu-died the statistical distribution patterns of permeability and porosity of tight reservoirs,and analyzed the causes for reservoir tightening and the characteristics of tight gas accumulation.Data show that over 80% routine permeability data points have a permeability less than 0.1×10-3 μm2.The corrected in-situ permeability is about one order of magnitude lower than the routine permeability.Taking the routine permeability value of 0.1×10-3 μm2 as the upper limit of tight gas sands is reasonable and practical.Statistics of tight gas sands over the world shows that tight sandstone reservoirs have diversity of sedimentary environments,large depth span,and long time range in geological age.Tectonic activity,sedimentary environment and diagenesis are the main factors for the formation of tight reservoir,but they play a different role in different basins.The distribution of tight gas sands can be delineated by analyzing source rock,tectonic movements and rese-rvoir tightness.

Key words: routine permeability, in-situ permeability, reservoir physical property, tight gas

CLC Number: