莺歌海盆地泥底辟带中深层天然气勘探中的CO_2风险分析

在以往研究工作的基础上 ,结合近期所获地质资料的分析和天然气运聚成藏规律的研究 ,对莺歌海盆地泥底辟带中深层 (T30 以下 )天然气勘探中的 CO2 风险进行了分析 ,认为中深层 CO2 风险相对较小 ,中深层 CO2 分布与浅层 CO2 分布类似 ;CO2 等非烃气的局部富集主要与泥底辟及热流体上侵活动密切相关 ;在中深层寻找高产富烃天然气 ,必须选择构造规模大、储集条件好、相对低压低势且距泥底辟活动中心区较远的构造布井 ,以避免可能出现的 CO2 风险

A CO _2 RISK ANALYSIS FOR MID DEEP GAS EXPLORATION IN DIAPIR BELT,YINGGEHAI BASIN

Based on previous work and the latest geological data and study on gas migration and accumulation,this paper analyzes CO 2 risk for mid deep (below T 30 ) gas exploration in diapir belt,Yinggehai Basin,suggesting that the mid deep CO 2 risk is low relatively,and that the mid deep strata are similar in CO 2 distribution to the shallow ones. Localized accumulations of nonhydrocarbon gas,such as CO 2,are mainly related with mud diapir and upward movement of hot fluids. In order to find large hydrocarbon rich gas accumulations and to lower CO 2 risk,the targets to be drilled should be big structures with good reservoirs,relatively low pressure and fluid potential and far away from mud diapir centers.