渭河盆地固市凹陷含氦地层识别技术应用及勘探开发启示OA

Helium is a scarce strategic resource,and it is imperative to advance helium resource exploration and re-lated technological research.The Weihe Basin is well endowed with helium resources,but its overall exploration lev-el remains low.The lack of mature identification techniques and evaluation criteria for helium-bearing strata has constrained the large-scale exploration and development of helium resources.To slove this problem,and in combina-tion with the conditions for helium accumulation and helium-content detection methods,this study established a set of identification techniques and evaluation criteria for helium-bearing strata based on the latest exploration results from the southern slope of the Gushi Sag in the Weihe Basin.The results show that helium reservoirs strictly follow the three core elements of"generation-migration-accumulation",which control the entire process of helium genera-tion,migration,and accumulation.By integrating while-drilling helium detection,conventional mud logging proce-dures for oil and gas wells,and well-log interpretation and evaluation,a technical standard system for identifying he-lium-bearing strata was established.The key parameter indicators were defined as helium content of 0.050‰-0.100‰,total hydrocarbon content of 2%-3%,P-/S-wave velocity ratio of 1.6-1.8,gas saturation of 20%-30%,acoustic travel time of 330-380 μs/m,bulk density of 2.2-2.4 g/cm3,and lithologies including siltstone,sandstone,and mudstone.Through field application,multiple Class Ⅰ,Class Ⅱ,and Class Ⅲ helium-bearing res-ervoirs were delineated in several exploration wells on the southern slope of the Gushi Sag.The establishment and application of the helium-bearing strata identification technology further demonstrate the local occurrence of helium reservoirs on the southern slope of the Gushi Sag,and provide useful guidance for the future direction of helium re-source exploration and development in the Weihe Basin.