克拉美丽气田火山岩气藏产能评价及配产方法研究

Productivity Evaluation and Production Allocation Methods of Volcanic Reservoir in Kelameili Gas Field

克拉美丽气田属火山岩气藏,由于受火山喷发多期性影响,其岩性岩相变化较快,岩性致密,储层物性平面非均质性严重,渗透性很低、且渗透率差异很大,因而气井产能差异很大:不同岩性单井绝对无阻流量在(16.22～109.34)×104m3/d之间,同一岩性的正长斑岩单井绝对无阻流量在(21.83～56.71)×104m3/d之间,因此评价比较困难。如何科学、合理地评价其产能,在其开发过程中显得非常重要。首先利用动静结合的方法给出了气井的分类标准,接着利用产能方程法对其进行评价,最后综合利用产能方程和动态储量联合配产法、试采压降法、试井模型预测法、试气绝对无阻流量法、采气指数法、最小泄液法和管内冲蚀流量法等方法,对每类气井进行了配产研究,提出了每类井的合理配产范围。配产结果对今后该气田新井的单井配产具有一定的参考价值。

Kelameili Gas Field is a volcanic gas reservoir.Influenced by multistage volcanic eruption,its lithology and lithofacies change fast with dense lithology,and areal heterogeneity of physical property of reservoirs is severe and difference of permeability is large with low value.So there are large differences on productivity among gas wells.Evaluation on production capacity of the single well is difficult for(16.22-109.34)×104m3/d of absolute open flow in the single well with various lithology and(21.83-56.71)×104m3/d of that in single well with the same orthophyre.Therefore,how to scientifically and rationally evaluate its capacity in its development process is very important.Firstly,the method of combining static and dynamic classification of gas wells is given;Secondly,evaluation is made by deliverability equation method;finally,production allocation is researched and reasonable limit is known for each type of gas well through many methods applied comprehensively.These methods include the methods of production allocation of dynamic reserve,production test-pressure drop,test model prediction,absolute open flow by gas test,gas productivity index,the smallest gas leak fluid index and erosion flow rate and others.The result of production allocation has certain reference value for the future single well production allocation in this gas field.