徐深气田A区块火山岩气藏开发动态特征

DYNAMIC CHARACTERISTICS OF THE VOLCANIC GAS RESERVOIR DEVELOPMENT IN BLOCK A OF XUSHEN GASFIELD

徐深气田中的A区块是中国较早系统开发的火山岩气藏,正确认识其动态特征是开发好气藏、保障平稳供气的关键。运用气藏工程、不稳定试井、生产统计等手段,从气井的井控区域流动特征、生产流动状态、生产动态特征、地层压力变化特点以及产水特征等方面总结了A区块火山岩气藏的开发动态特征。气井井控区域的物质基础以连续分布的低孔渗为主,流动几何形态主要为线性流动;气井定产量生产中不易进入拟稳态,生产流动状态主要为不稳定状态;气井井底流压与地层压力下降幅度不一致,一般流压的递减率高于地层压力的递减率,许多井呈现间歇生产特点;各个井区受到物性、连通性差异的影响,在控制储量、产量水平上差异大,采出程度各不相同,导致地层压力变化不均衡;气井生产中普遍产水,依据出水来源划分为边底水、凝析水以及可动水等3种出水类型。

A Block in Xushen Gasfield is earlier systematically developed volcanic gas reservoirs in China. Correct understanding the dynamic characteristics of the reservoirs is the key to well develop the reservoirs and guarantee the stable supply of the gas. With the help of gas reservoir engineering, non-stablized well test, production statistics and so on, the behavioral characteristics of the reservoir development are summarized from the aspects of flowing features ＆ states, production performances, the changed characteristics of the formation pressure, produced water features and so on in the region controlled by the gas wells. The material base is mainly the low porosity and low permeability continuously distributed in the above region, the flow geometric shape is generally linear flow; it is very difficult to access pseudosteady state in the process of stablizing the gas production, the main production flow condition is non-steady state; the bottomhole flowing pressure is disagree with the decline degree of the reservoirpressure： in general, the declining rate of the flowing pressure is higher than that of the reservoir pressure, many wells are characterized by batch production; influenced by the differences of physical properties and connectivity, there are great contrasts in the control levels of the reserves and production, and moreover so does the degree of produced recovery, thus the unbalanced change in the reservoir pressure happens at last ; in the course of gas pro- duction, water is generally produced, according to the water source, the water is divided into three kinds： edge- bottom water, condensated water and movable water.