用壤中游离烃现场分析解释技术直接寻找浅层油气藏

壤中游离烃技术采用车载高精度气相色谱仪和车载专用钻机采样设备，进行壤中气态烃（C1—C5）直接进样分析。该技术较好地解决了壤中气采集与分析过程中的密封性和微量、超微量烃气的检测问题，实现了样品采集、分析与解释的现场化和一体化。相对于土壤吸附烃或酸解烃测量，游离烃异常能够更好地反映地下油气藏中烃气的现代活动状况，且较少受到地表景观和岩性条件的影响。内蒙古二连盆地吉尔噶郎图凹陷的稀油勘探和新疆塔里木盆地大宛齐地区浅层油气藏的滚动勘探应用实例表明，该技术在浅层油气田勘探领域具有较好的应用效果。同时指出，壤中游离烃技术，还不能很好地判断异常与油气的绝对对应关系，不能回答含油气多少等问题。在圈闭评价或钻探中，化探成果要与地震、地质等资料紧密结合，进行综合分析，特别强调不要跨跃勘探阶段使用化探资料。

Shallow oil and gas reservoir exploration in using on-site analysis and interpretation technology of free hydrocarbons in soil

Soil free hydrocarbon technology is based on high-precision gas chromatography and vehicle-mounted rig sampling equipment, directly using gaseous hydrocarbons (C1-C5) in the soil into the sample analysis. This technology can solve the detection of micro-, ultra-volume hydrocarbon gas during soil gas collection and sealing, which has achieved collection, analysis and interpretation all on site and integrated. Compared to absorbed or acidextraction hydrocarbon measurement, free hydrocarbon anomaly can better reflect the movement of hydrocarbon gas in underground reservoirs, and it is less vulnerable to surface landscape and lithologic conditions. Practices of thin oil exploration in Jiergalang Depression, Inner Mongolia and shallow propecting in Dawanqi area, Xinjiang's Tarim Basin have shown that the technology has a good effect in the field of shallow oil and gas exploration. At the same time this paper has pointed out that this technology can not be used to define the absolute anomaly correlation with the oil and gas, and it can not answer how much oil and gas is enriched. In the trap evaluation or drilling survey, it's better to combine closely geochemical results with the seismic, geological and other information together to carry out a comprehensive analysis, it has been specially emphasized that there should not be any big leap of exploration stages in using geochemical data.