川东北YB地区长兴组生物礁储层特征精细研究及意义

Fine Study on Reef Reservoir Characteristics and Its Significance of Changxing Formation in Yuanba Area

川东北YB地区长兴组是一大型生物礁岩性气藏,储层精细研究是YB地区天然气分布、储量及产能的主控因素。长兴组生物礁储层以Ⅱ、Ⅲ类储层为主,纵向上主要分布于长二段第2个四级旋回的高位体系域中,平面上工区西部Ⅲ、Ⅳ号礁带Ⅰ、Ⅱ类储层较东部Ⅰ、Ⅱ号礁带更发育,测试证实为高产富集带。综合实际测试成果并利用氦气法、煤油法及测井法等3种方法对储层物性与储层产能进行定量回归分析,分析表明,YB地区主要为中高产气藏。

Changxing Formation of Yuanba Area in northeastern Sichuan is a large reef flat lithologic gas reservoir.The analysis on reef reservoir characteristics of Changxing Formation shows that the main reservoir is Type Ⅱ,Ⅲ reservoirs.In the longitudinal direction,reservoir distributes mainly in the second fourth order cycles of highstand system tract of Chang-2Member,in the plane,TypeⅠ,Ⅱreservoirs of No.Ⅲ,Ⅳreef belt in the northwest are better than No.Ⅰ,Ⅱ reef in the east and it is a high enrichment zone proved by testing result.Reservoir characteristics qualitative analysis shows that both the thick reservoir with good property and the thin reservoir with good reservoir space type are easier to capture high yield commercial gas.Meanwhile,through quantitative regression analysis on porosity parameters &testing deliverability using the helium method,kerosene method and logging method,it is pointed out that Yuanba Area is mainly a middle-high gas pool.