论川中石炭系油气勘探

川中石炭系油气源条件稍逊于川东,但储层、油气运聚和盖保条件等都不比川东差。川中北部局部构造小,断裂发育,古构造部位低,石炭系埋藏深;川中南部,石炭系在古构造发展中一直处于有利于油气聚集的高部位,埋藏较浅,局部构造平缓,断裂少,保存条件好,除有构造圈闭外,并可能有非构造圈闭,如罗渡地层超覆圈闭和代市岩性圈闭,应是勘探的重点区。

ON C ARBONIFEROUS HYDROCARBON EXPLORATION IN CENTRAL SICHUAN

The source rocks of discovered Carboniferous gas region both in central andeast Sichuan are underlying Silurian System.Though the thickness and organic abundance of the source rocks in central Sichuan are not as good as that inthe east part,the Ordovician System in central Sichuan is also fine source rock,which may make up a defect for Silurian.The porous bed of the Fucheng-zhai member in central Sichuan—the main reservoir—could be compared withthat of east Sichuan whether in the total thickness or the thickness percentage of the whole member and the weighted mean porosity.The southern part ofcentral Sichuan is in the upper part of a uplift,conditions for hydrocarbon migration and accumulation are no less favourable than that of east Sichuan.In especial,cap and trap conditions are evidently superior to that of the east.In consideration of the above conditions,the author proposed not to domore drilling in the north part,and that the south part should be an impor-tant target for hydrocarbon exploration in central Sichuan.