潘汉得——胡果顿与普光气田形成条件对比及启示

摘要

Panhandle-Hugoton gas field in North America and Puguang gas field in Sichuan basin of China are all giant marine carbonate gas fields in the world. It is suggested from comparison and analysis of the geological setting, pool-forming condition and process of these two gas fields that Panhandle-Hugoton and Puguang gas fields are all characterized by multiple source rocks, good reservoir rocks with mid- dle-high porosity and permeability, and the gas pools suffered multistage reformation and stabilization controlled by late tectonization, and gypsum and salt cap rocks. The most difference between them is the development degree of their cap rocks. The thickness and continuity of regional gypsum and salt cap rock in Panhandle-Hugoton gas field are clearly superior to those in Puguang gas field, showing that the seal- ing and preserving condition are the key factors for the formation of giant gas field under the geologic conditions of sufficient gas source and good reservoir. It is predicted that other giant gas fields the same as or even larger than Puguang could be found in the areas where both reef -flat reservoirs in Feixianguan formation and gypsum and salt cap rocks in Jialingjiang formation are developed, such as Wanzhou and Da- zhu areas, in South China.%分析了北美潘汉得—胡果顿气田和我国普光气田的地质背景、成藏条件与成藏过程指出,二者均发育多套烃源岩,储集层物性均较好,盖层岩类均为膏盐岩,经后期多期变动与调整而定型于晚期。但二者间最显著的差异在于盖层的发育程度：前者的膏盐岩直接盖层分布范围广、厚度巨大、断层不发育,明显优于普光气田。说明在气源充足、储集层发育良好的地质条件下,盖层及保存条件是形成大气田的最关键因素。据此预测,在中国南方飞仙关组礁滩优质储集层和嘉陵江组膏盐岩盖层发育重叠区,如万州和大竹地区,有望发现更大规模的天然气田。