临界携液流量与流速沿井筒分布规律研究

Research on distribution of critical carrying fluid flow rate and velocity along shaft

随着大牛地气田的不断开发,气井压力逐渐降低,气井积液越来越严重,准确预测气井的临界携液流量与流速对气井的配产以及积液判断有着重要的意义。除了寻找适合本气田的临界携液流量模型外,还要考虑最大携液流量在井筒中出现的位置。为此,文中通过建立气井临界携液流量模型与井筒压力、温度分布模型,以流压测试数据为基础,对临界携液流量与流速沿井筒的分布规律展开研究。结果表明:当压力梯度小于临界压力梯度时,临界携液流量随井深增加而减小,当压力梯度大于临界压力梯度时,临界携液流量随井深增加而增加;温度梯度为分别为1.5,2.0,2.5,3.0℃/100 m,临界压力梯度分别为0.04,0.05,0.06,0.07 MPa/100 m。

With the development of Daniudi Gas Field, the pressure of gas well reduces gradually and the wellbore accumulation in gas wells becomes more and more serious. Accurate prediction of critical carrying fluid flow rate and velocity has important implication for the production allocation of gas well and the effusion judgment. Apart from seeking the model suitable for critical carrying fluid flow rate, the location of maximum carrying fluid flow rate should be also considered. For this purpose, by establishing critical carrying fluid flow rate model, wellbore pressure distribution model and temperature distribution model, this article studies the distribution of critical carrying fluid flow rate and velocity along the shaft based on the test data of flow pressure. The results show that when the pressure gradient is less than the critical pressure gradient, the critical carrying fluid flow rate decreases with the increase of well depth,conversely, it increases with the increase of well depth. Temperature gradients are 1.5 ℃/100 m, 2.0 ℃/100 m, 2.5 ℃/100 m, 3.0 ℃/100 m and the corresponding critical pressure gradients are 0.04 MPa/100 m, 0.05 MPa/100 m, 0.06 MPa/100 m, 0.07 MPa/100 m.