Abstract:

The main controlling factors of coalbed gas reservoir formation include right pressure system, right transit system and corresponding energy mechanism, which is the spacetime configuring relation of effective pressure system and effective transit system of coalbed gas reservoir substantively. Flexibility energies of coalbed gas reservoir are just about ties between the two systems. Different flexibility energy models are put forward in the paper, threeunit differentiate symbols of coalbed gas reservoir formation function including crevice growth degree coefficient ζ1, crevice open and close degree coefficient Δ, and effective pressure system growth degree coefficient ζ2 are established, and their distributing laws in Qinshui Basin are discussed. ζ1 and Δ can show effective transit system quantificationally, while ζ2 can show effective pressure system quantificationally. According to threeunit differentiate symbols, the controlling function of coalbed gas reservoir formation of flexibility energies is analysed, threeunit model on differentiating coalbed gas reservoir formation style was advanced. The research results considered that there are 27 sorts of styles of coalbed gas reservoir formation function, but just 8 sorts are propitious for coalbed gas enrichment and high produce. Actually only 2 favorable styles in Qinshui Basin are effective pressure system and effective transit system distributing in DaningPanzhuangFanzhuang zone of southern basin, and rather effective pressure system and rather effective transit system distributing in QinshuiZhengzhuangFanzhuang zone of southern basin and QinyuanAnze zone of middle basin.

Key words: flexibility energies of coalbed gas reservoir, effective pressure system, effective transit system, styles of coalbed gas reservoir formation function, Qinshui Basin