川东地区石炭系天然气成藏动力学研究

川东地区是四川盆地稳定地块中的相对构造活动区,发育10排高陡构造带.应用油气成藏动力学的原理和方法,剖析了石炭系碳酸盐岩储层油气成藏的主控因素,恢复与再现了石炭系天然气成藏动力学过程.研究成果表明,可将二叠系阳新统的现今流体压力系数1.30作为对石炭系气藏压力封闭的临界值.石炭系为具正常地层压力的区域孔洞型储集体,致使大规模的褶皱型构造圈闭成为仓储空间,石炭系捕集成藏的天然气又是在高压驱使下上下邻层流体跨层充注的结果.川东地区石炭系天然气的成藏动力学特征可归纳为:"压力封闭,流体上下充注,天然气仓储式成藏".

Dynamics of natural gas pools of Carboniferous in the eastern Sichuan Basin

The eastern area of Sichuan Basin with ten complete tectonic belts is the relatively active tectonic belt. The main control factors for formation of the Carboniferous carbonate gas pools were analyzed with dynamics. The dynamic process of the Carboniferous gas pools in this area was recurred. The results show that the pressure coefficient of 1.30 for Yangxin Series of the Permian can be taken as the critical value for pressurizing the Carboniferous gas pools. The carboniferous gas pool has a regional cavity with normal pressure, which turn the large-scale folding deformational trap into stock bin. The Carboniferous gas pool is resulted from cross-formation pouring of natural gas driven by high pressure from adjacent stratum. Therefore, the dynamics of natural gas pools of the Carboniferous in the eastern Sichuan basin can be characterized by pressure seal, fluid pouring from adjacent stratum, and hydrocarbon accumulation by stock bin.