致密火山岩凝析气藏生产动态特征与影响因素研究——以龙凤山气藏B213井区为例

Research on production dynamic characteristics and interfering factors of tight volcanic condensate gas reservoir——Taking B213 well area of Longfengshan gas reservoir as an example

为了明确不同期次气井的产能特征,摸清致密凝析气藏的生产规律和影响因素,从静态和动态两方面入手,结合龙凤山气藏B213井区生产实际,分析归纳出各个期次气井产气量、产油量、产水量的差异特征及影响因素;通过与不同气藏物性进行对比,结合气井相图特征,归纳出龙凤山凝析气藏的特点;结合产气量递减率、气油比、油压压降速率、静压压降速率等生产动态指标,分析工作制度对气藏开发过程的影响。结果表明:1)受火山机构含气性、有利相带占比、储层电性物性、气井所处构造部位等因素的影响,期次5产气量和产油量最高,期次3产水量最高,期次4几乎不产油;2)龙凤山凝析气藏储层致密,含油量高,地露压差小,生产规律更加复杂,反凝析控制更加困难;3)初期的高配产工作制度会导致气藏递减加快、气油比上升、压降速率过快,加剧反凝析的影响。以上成果认识,对同类气藏的开发具有一定的借鉴作用。

In order to clarify the productivity characteristics of gas wells in different periods and find out the production rules and influencing factors of tight condensate gas reservoirs, this paper starts from static and dynamic aspects, combined with the production practice of B213 well area in Longfengshan gas reservoir, the characteristics and influencing factors of gas production, oil production and water production of gas wells in each period are analyzed and summarized;By comparing with the physical properties of different gas reservoirs and combining with the phase diagram, the characteristics of Longfengshan condensate gas reservoir are summarized;Combined with the decline rate of gas production, gas oil ratio, oil pressure drop rate and static pressure drop rate, the influence of working system on gas reservoir development is analyzed. The results show that: 1)Affected by the gas bearing property of volcanic bodies, the proportion of favorable facies, the electrical and physical properties of reservoir, the structural position of gas wells and other factors, period 5 has the highest gas and oil production, period 3 has the highest water production, and period 4 has almost no oil production;2)The reservoir of Longfengshan condensate gas reservoir is compact, with high oil content and little difference between the formation pressure and dew point pressure, so the production law is more complex and it is more difficult to control retrograde condensate;3)The initial high production allocation system will accelerate the decline of tight condensate gas reservoir, increase the gas oil ratio, and increase the pressure drop rate. The above results can be used for reference in the development of similar gas reservoirs.