四川盆地安岳特大型气田不同产能状态下龙王庙组的储层特征

下寒武统龙王庙组是安岳特大型气田的主力产气层,认识和刻画其储层特征对勘探开发至关重要。基于对安岳气田不同产能状态下龙王庙组储层的岩性、类型以及不同类型储层的厚度占比和孔洞发育情况的分析,建立高产井、中产井、低产井和干井中储层特征与油气产能的联系,其结果表明：龙王庙组储层主要发育于颗粒白云岩和结晶白云岩层段,储集空间有溶蚀孔洞、粒间溶孔、晶间溶孔和裂缝等,其中,孔洞和孔隙是主要类型;孔洞型储层是安岳气田中龙王庙组高产井的主导储层,其占比、孔洞发育密度、孔洞大小、孔洞段的单层厚度和累计厚度等是影响油气产能的主要因素;孔洞型储层的非均质性强,孔径呈双峰分布,表现为大尺寸（毫米级和微米级）的孔洞和小尺寸（纳米级）的晶间孔、晶间溶孔;孔隙型储层的孔隙分布均匀,孔径呈单峰分布,主要发育微米级孔隙。

Reservoir characteristics of Longwangmiao Formation under different productivity conditions in the Anyue giant gas field,Sichuan Basin

The Lower Cambrian Longwangmiao Formation is the main gas production formation of the Anyue giant gas field and its reservoir characteristics are very important for hydrocarbon exploration and development. Based on analyzing the lithology and type of the Longwangmiao Formation reservoirs under different productivity conditions, as well as the thickness ratio and pore development of different types of reservoirs in the Anyue gas field, this paper establishes the relationships between reservoir characteristics and hydrocarbon productivity in high-productivity, medium-productivity and low-productivity wells as well as dry wells. The results show that the Longwangmiao Formation reservoirs are mainly developed in granular dolomite and crystalline dolomite intervals. The reservoir spaces contain solution vug, intergranular dissolved pore, intercrystalline dissolved pore, and fracture. Vug and pore are the main types. The vug-type reservoir is dominant for high productivity wells in Longwangmiao Formation of the Anyue gas field, and its proportion, vug density, vug size, single layer thickness and cumulative thickness of the vuggy section are the main factors affecting hydrocarbon productivity. The vug-type reservoir has strong heterogeneity, and the vug size shows a bimodal distribution, corresponding to large-size (millimeter and micron scale) vugs and small (nanoscale) intercrystalline pores and intercrystalline dissolved pores. The pore-type reservoir exhibits a uniform pore distribution and a unimodal pore size distribution dominated by micron-scale pores.