高压气井产能评价方法研究

High-pressure gas well productivity evaluation.

确定气井产能有回压试井、等时试井与修正等时试井 ,这些方法所需的试井时间长 ,增加勘探成本且浪费资源。为此研究了利用不稳定试井资料确定气井绝对无阻流量的新方法 ,并以KL2 0 3井为例 ,比较了计算气井绝对无阻流量二项式压力法、二项式压力平方法、指数式压力法、指数式压力平方法、一点压力法、一点压力平方法、新一点压力法、新一点压力平方法等方法的有效性 ,得到如下认识 :在计算高压气井的产能时 ,用压力法比用压力平方法合适 ;如高压气井进行了产能试井 ,用二项式压力法来计算绝对无阻较合适 ;如只进行了不稳定试井或进行了产能试井 ,但单位产量的压差与产量不相关 (相关系数小 )或负相关时 ,应采用新一点压力法较合适 ;在其它方法均失败时 ,近似使用一点压力法。表 2参

There were three methods determining gas well productivity, whi ch are back pressure testing, isochronal testing and modified isochronal testing . These methods all need a long testing time, which can lead to the increase of exploring cost and the waste of resource. For these reasons, a new method determ ining gas well absolute open flow by using transient well testing data is studie d in this paper. Taking Well KL203 as an example, the efficiencies of using seve ral kinds of method to calculate gas well absolute open flow rate, such as binom ial pressure method, binomial pressure squared method, exponential pressure met hod, exponential pressure squared, one point pressure method, one point pressur e squared method and new one point pressure squared method have been compared. Se veral conclusions were given as below: pressure method is more suitable for calc ulating high pressure gas well productivity than pressure squared. Under the c on dition that productivity well test has been made, the binomial pressure method i s more suitable for calculating absolute open flow. Under the condition that onl y transient well test has been made or productivity testing has been made but th e pressure difference per unit production are not correlated or negatively corre lated with production, the new one point pressure is suitable. If all other meth ods are all unsuccessful, the one point pressure method can be used approximatel y.