典型气藏上方地表化探特征分析——以四川盆地孝泉—新场气田为例

ANALYSIS OF SURFACE GEOCHEMICAL CHARACTERISTICSOVER TYPICAL GAS POOL——TAKE XIAOQUAN-XINCHANG GAS FIELD IN THE SICHUAN BASIN AS AN EXAMPLE

任春 夏响华

Ren Chun Xia Xianghua

中国石油化工股份有限公司, 石油勘探开发研究院, 无锡石油地质研究所, 江苏, 无锡, 214151

Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214151, China

四川盆地孝泉—新场气田上方地表油气化探指标与气藏关系的分析非常明确地显示出,地下气藏在地表留下的各种地化痕迹与气藏的类型和规模有着密切的关系,利用地球化学检测手段,可以捕捉这些微量痕迹,从而为勘探地下气藏提供可靠依据。地表油气化探指标酸解烃、ΔC、热释烃、微磁的异常形态主要为环状(或环斑状);顶空气对天然气藏有很好的指示作用,在气藏上方的主要特征是浓度变化大,在气藏外浓度变化小;微生物指标与气藏有较好的对应关系,甲烷氧化菌具有明显的环状(环斑结合)特征,硫酸盐还原菌具有典型的顶端异常特征。多指标综合,结合地质进行分析,是减少天然气藏预测风险,提高勘探成功率的有效途径。

By analyzing relations between surface geochemical indicators and deep gas pool in Xiaoquan-Xinchang gas field of the Sichuan Basin,one can obviously obtain that large numbers of surface geochemical tracks from deep gas accumulations is closely response to the types and scales of deep gas accumulations.Using geochemical detecting methods,one can catch these micro-traces,thus providing deep gas accumulations exploration with reliable basis.The anomaly shape of acid hydrocarbon,ΔC,heat-released hydrocarbon and micro magnetism is mainly annular or spotted.Head-space gas is a good indicator to deep gas accumulations.It is characterized by concentration changing greatly over gas accumulation and changing little out of gas accumulation.Microbiological indicator is corresponding to deep gas accumulation.Methane oxidation bacteria have annular or spotted anomaly features.Sulfate-reducing bacteria show a character of top anomaly.For reducing risk of prediction and increasing rate of success in gas exploration,it is needed to combine surface geochemical indicators with geologic setting.

中国石化股份公司科研项目(P00012)

https://doi.org/10.11781/sysydz200602182