辽河盆地东部凹陷深部煤层气成藏条件评价

EVALUATION OF RESERVOIR FORMING CONDITIONS OF DEEP COALBED METHANE,EASTERN SAG,LIAOHE BASIN

辽河盆地是我国煤、油、气共生盆地之一,开展该盆地东部凹陷深部煤层气成藏条件评价,对于优选煤层气有利探区,实现该区煤层气与常规油气共采具有重要意义。从气源条件、储集条件和保存条件3个方面,分析了东部凹陷深部煤层气的成藏条件,并对其进行综合评价,结果表明东部凹陷具有煤层分布面积广、厚度大、变质程度低、含气量低、含气饱和度高、埋藏较深、煤层气地质储量丰富及保存条件良好等特点,认为该区煤层气成藏条件较好,能够实现与常规油气共采,具有很好的勘探开发前景。

Liaohe basin is a special type basin with coal, oil and gas resources. It is important to evaluate reservoir forming conditions of deep coalbed methane for selecting favorable exploratory areas and developing unconventional coalbed gas and conventional oil and gas resources together in the eastern sag of the Liaohe basin. The paper analyzes reservoir forming conditions from gas source, reservoir and preservation, and makes a comprehensive evaluation. The result indicates that coal beds in the sag are characterized by wide distribution, big thickness, low metamorphic grade, low coalbed methane contents, high coalbed methane saturation, deep buried depth, coalbed methane of abundant geological reserve and favorable preservation. It also shows that reservoir forming conditions of deep coalbed methane are favorable, deep coalbed methane resources are plenty, unconventional coalbed methane can be developed together with normal oil and gas resources and deep coalbed methane has a good prospect of exploratory development in the sag.