浅议天然气、煤层气、页岩气成藏特征及勘探开发

Discussion on the accumulation characteristics and exploration of natural gas,coalbed methane and shale gas

煤层气和页岩气是非常重要的非常规天然气藏。天然气、煤层气、页岩气三者在成藏特征、成藏机理和勘探开发上既有相似性又有差异性。对比分析表明,常规天然气藏需要有生、储、盖的合理组合,勘探开发技术成熟,工艺较简单,生产周期一般较段;煤层气、页岩气气藏表现为自生、自储、自保的特征,煤层气藏为吸附成藏机理,页岩气藏自身构成了从吸附聚集、膨胀造隙富集到活塞式推进或置换式运移的机理。煤层气勘探开发较常规页岩气复杂,初期产量低,但生产周期长;页岩气主要采用水平井和压裂技术开采,开采周期最长。

Coalbed methane and shale gas are very important unconventional natural gas reservoirs.Natural gas,coalbed methane and shale gas have similarities and differences in the characteristics of accumulation,accumulation mechanism and exploration and development.The comparative analysis shows that the conventional natural gas reservoir needs a reasonable combination of production,storage and cover.The exploration and development technology are mature,the process is simple,and the production cycle is generally relatively segmented;the coalbed methane and shale gas reservoirs are self-generated,self-storage and self-protection.The characteristics of coalbed methane reservoirs are the mechanism of adsorption and accumulation.The shale gas reservoirs itself constitutes the mechanism from adsorption and accumulation,expansion and accumulation to piston propulsion or displacement.Coalbed methane exploration and development is more complex than conventional shale gas,with low initial production,but long production cycle;shale gas is mainly mined by horizontal wells and fracturing technology,and the mining cycle is the longest.