气井产能分析方法研究

Analysis method for gas well deliverability

用常规方法处理产能测试数据时,发现许多气井的井底压力测试数据很难达到常规气井产能分析方法的基本要求:每改变一个工作制度(每改变一次产量),气井的井底压力应达到稳定后才能测试压力,可是,达到"拟稳定流状态"比较难。这就使得测试压力与达到稳定时的压力有一定的误差,针对这种情况,提出一种新的分析方法,该方法引入测试点的误差值,建立带约束条件的优化模型,从而获得可靠的结果。该方法克服了测试中需要长时间达到稳定状态这一限制,同时可以缩短测试时间,对低渗透储层特别适用。通过实际资料处理与对比分析,验证了该方法的实用可靠性。

When deliverability test data is analyzed with normal methods, much data of pressure get to basic require of normal deliverability test very hard.That is to say,once the working system is changed and the pressure in the hole of the gas well must get to stabilization to be tested,even the test pressure is hard to reach to the pseudo-stable flow state.So the testing pressure has some error with the stable pressure. Aiming at this instance,a new analysis method is presented.It quotes errors to dispose the test data, sets up optimization model the most which restrains the condition,so preferable effect can be gained. This method is developed to overcome the limitation of long testing times required to reach stabilization in the flow test, and the test time can be shorten. It is especially applicable to low permeability layer. Through the analysis of example, it further demonstrates that this method is useful and reliable.