莺歌海盆地天然气运聚成藏条件与分布富集规律

Natural gas distribution and reservoir-forming law of the Yinggehai Basin,China

油气勘探实践表明莺歌海盆地的天然气形成、分布及保存均与底辟区超压体系密切相关。文章根据地震、测井及地质资料与钻探成果,系统地分析总结了莺歌海盆地天然气生成、运聚及富集成藏特征。研究表明,莺歌海盆地天然气分布往往具有浅层气田沿中央泥底辟带分布、中深层岩性气藏分布于底辟构造翼部的特征,且具有"流体超压驱动、底辟裂缝输导、重力流扇体储集、高压泥岩封盖、天然气幕式脱溶成藏"的运聚成藏及富集规律。

Oil-gas exploration in the Yinggehai basin shows, the formation, distribution and preservation of oil and gas resources are closely related to the overpressure system in the diapir zone. We based our analysis of the characteristics of generation, migration and reservior-forming of oil and gas resources on a full integration of geological logging and seismic data as well as drilling outcomes in the Yinggehai basin. Our research results show that the distribution of natural gas, is generally characterized by shallow gas reservoir along the central mud diapir zone and middle deep lithologic gas reservoir along the limb of diaper zone. The reservior-forming and enrichment follows the law of “driven by overpressure, conduction via fracture of diapir, enrichment in fan deposit possessed by gravity flow, capping with high pressure mudstone, pool-forming of episodic water-soluble gas ”.