复杂底水型气藏储层发育控制因素及气水分布模式--以四川盆地龙岗礁滩型碳酸盐岩气藏为例

摘要

Controlled by the deposition and diagenesis, the reservoir heterogeneity of carbonate gas reservoir is serious and the gas water distribution is also complex. This ifeld shows scattered bottom water characteristics. The paper takes the Longgang gas reservoir as an example to analyses the controlling factors of reservoir development, gas water distribution and gas well development characteristics. Results showed the ifeld of Longgang is controlled by sedimentary facies, dolomitization, dissolution and fracture. The favorable sedimentary facies is the material basis in the development of reservoir. The dolomitization is a plus factor. The dissolution is a key factor and the fracture is an effective way to increase permeability. Gas water analysis indicated Longgang gas reservoir hadfour gas water distribution patterns which included thin formation edge water, thick massive bottom water and layered gas reservoir. Gas water distribution and enrichment regulation were controlled by structure, reservoir permeability body morphology, physical properties, fracture, the tight layer updip direction of reservoir permeability body, and the degree of gas supply in the process of gas accumulation. The wells which have different gas water distribution pattern have different development characteristics. According to these characteristics, we can make the development strategies so as to improve the effect of gas reservoir development.%受沉积和成岩作用控制，礁滩型碳酸盐岩气藏储层非均质性严重，流体分布极为复杂，这一类型气藏整体表现为分散底水型特征。以龙岗礁滩型碳酸盐岩气藏为例，研究储层发育控制因素、气水分布规律及生产特征。储层研究结果表明，礁滩型碳酸盐岩气藏储层受沉积、白云石化、岩溶和裂缝控制，有利沉积相带是储层发育的物质基础，白云石化作用是储层形成的有利因素，岩溶作用是优质储层形成的关键所在，裂缝能有效增加储层渗透性。动静态资料综合分析龙岗气田气水分布类型主要有薄层状边水型、厚层块状底水型和层状纯气型。不同类型气水分布特点和富集规律受构造、储渗体形态、储渗体物性、裂缝和储渗体上倾方向致密层遮挡以及气源充足程度控制。不同流体分布模式气井具有不同的生产特征，根据这些特征制定有针对性的开发技术政策，可有效提高气藏开发效果。