松辽盆地南部深层火山岩储层成岩作用类型及特征

Diagenesis types and characteristics for deep volcanic reservoir in southern Songliao Basin

松辽盆地南部深层上侏罗统火石岭组和下白垩统营城组广泛发育火山岩，是该区主要的储层。近年来，在松辽盆地南部火山岩油气勘探过程中，深层火山岩气藏呈现出良好的勘探前景，决定火山岩储集性能的主要因素之一就是其成岩作用方式。利用火山岩露头样品、岩心观察及薄片鉴定等资料，对松辽盆地南部深层火山岩储层的成岩作用进行详细研究。将研究区火山岩储层的成岩作用划分为早期成岩作用阶段和晚期成岩作用阶段，探讨了各种火山岩成岩作用的类型及特征。其中，早期成岩作用可分为挥发分逸出、熔蚀作用、等容降温冷凝结晶、准同生期热液沉淀结晶、熔结作用、冷凝收缩作用和压实固结作用：晚期成岩作用主要包括充填作用、脱玻化作用、交代作用、机械压实压溶作用和溶解作用。早期成岩作用阶段的溶蚀、等容降温冷凝结晶、冷凝收缩作用和晚期成岩作用阶段的脱玻化作用、交代作用、溶解作用有利于形成有效储层：而早期的压实固结作用、准同生期热液沉淀结晶和晚期的充填作用、机械压实压溶作用对储层储集空间发育不利。

Both the Huoshiling Formation of Upper Jurassic and the Yingcheng Formation of Lower Cretaceous have extensively developed volcanic rocks, which are the main reservoirs in the southern Songliao Basin. In recent years, the exploration of deep volcanic gas reservoir presents a promising prospect in this area. The diagenesis is one of the main factors affecting the accunmlation performance of volcanic reservoir. The diagenesis of deep volcanic reservoir in the southern Songliao Basin is thoroughly investigated through the integration of volcanic outcrop samples, well core observation and thin section identification data. The diagenesis of volcanic reservoir in this area is divided into two phases including early diagenesis and late diagenesis. Specifically, the early diagenesis can be further classified into vaporization of volatile matter, reabsorption, isovolumetric condensing crystallization, pene-contemporaneous hydrothermal precipitation and crystallization, alloying, condensing constriction and consolidation. The late diagenesis consists mainly of filling, devitrifieation, metasomatism, mechanical impaetion and pressure solution and dissolution. The corrosion, isovolumetric condensing crystallization, condensing constriction in the early diagenesis phase and the devitrification, nletasomatism and dissolution in the late diagenesis phase are favorable for the form of effective reservoir. The early impaetion, pene-contemporaneous hydrothermal precipitation and crystallization and the late filling, the mechanical impaction and pressure solution can harm the developmemt of volcanic reservoir space.