松辽盆地北部天然气地质条件、资源潜力与勘探方向OA

In recent years,with the continuous emergence of new theories,understandings,and achievements in exploration,the results of the"13th Five-Year Plan"resource evaluation have shown an unsuitability to the current needs of exploration work,and a new round of resource evaluation is urgently needed to provide a basis for accelerating natural gas exploration and development in the Songliao Basin.By analyzing the geological conditions of natural gas in the northern Songliao Basin,focusing on four main source rocks of the Nenjiang Formation,Qingshankou Formation,Yingcheng Formation,and Shahezi Formation,and targeting four sets of oil and gas combinations in the upper,middle,lower,and deep parts,four reservoir formation models are established,including bedrock weathering crust gas reservoir,volcanic rock gas reservoir,paleouplift cap rock gas reservoir,and intra-source tight gas.Two major categories and five types of analog calibration areas are selected,and natural gas resource evaluation is mainly carried out using the analogy method.The estimated in-situ natural gas resources in the Songliao Basin are 27 002×108 m3,including 17 100×108 m3 of conventional gas and 9 902×108 m3 of tight gas.Based on the distribution of remaining resources and combined with the analysis of geological conditions for natural gas accumulation and enrichment,the next exploration direction has been further clarified.It is believed that the tight gas of the Shahezi Formation in the Xujiaweizi Fault Depression,the volcanic gas of the Yingcheng Formation in the Yingshan-Gulong Fault Depression,and the buried-hill gas of the bedrock in the Central Paleo-uplift Belt are the realistic areas for increasing reserves in the near future.