东海盆地丽水凹陷天然气成因类型

CLASSIFICATION OF GAS GENESIS IN LISHUI SAG OF EAST SEA BASIN

在东海盆地丽水凹陷的ZWS13- 1- 1、SLS36 - 1- 1和FLS - 1井发现了天然气 ,而ZWS13- 1- 1井的三个产气层段的二氧化碳含量均超过 94 % ,个别层段的二氧化碳含量高达 99.87% ,而FLS - 1井天然气中的二氧化碳含量却很低。研究表明 ,该区的二氧化碳既有有机成因的又有无机成因的 ,ZWS13- 1- 1井和SLS36 - 1- 1井天然气中的二氧化碳为无机幔源成因 ,而FLS - 1井天然气中的二氧化碳为有机成因。研究结果认为 :ZWS13- 1- 1井和SLS36 - 1- 1井天然气为油型气 ,而FLS - 1井天然气具有煤成气的特征 。

Natural gas has been found at wells ZWS13 - 1 - 1, SLS36 - 1 - 1 and FLS - 1 in Lishui sag of the East sea basin. The contents of carbon dioxide are above 94% in the 3 gas-producing formations of Well ZWX13 - 1 - 1: the content of carbon dioxide even up to 99.87% in some of them. But the content of carbon dioxide is quite low in Well FLS - 1. The study shows that the sources of carbon dioxide are from both organic and inorganic materials in this area. The carbon dioxide of the gas was generated from inorganic mantle origin in Wells ZWS13 - 1 - 1 and SLS36 - 1 - 1, while the carbon dioxide came from organic materials in Well FLS - 1. The study results indicate the gas from wells ZWS13 - 1 - 1 and SLS36 - 1 - 1 is oil-derived while the gas of Wells FLS - 1 - 1 is coal - derived.