"三高"气井现场测试作业过程中压力计无法接近产层中部,关井后井筒温度变化引起测点压力变化,对试井解释带来了较大的干扰.将地层渗流模型与井筒动力模型有机耦合,建立了井筒-气藏耦合的动力学模型.利用该模型研究不稳定试井压力计下入深度对试井解释结果的影响,绘制"三高"气井试井测试压力计最小下入深度图版,提出井口试井测试适应条件.研究表明,压力恢复试井最小测压深度(能反映地层真实渗流特征)主要受气井生产压差控制,其次受关井前生产产量控制;当生产压差大于10 MPa时,井口压力恢复试井即可满足试井解释条件;当生产压差小于10 MPa时,不同气井存在不同的最小测压深度,压力计只有下入最小测压深度以下,才能准确认识地层渗流特征.该方法为"三高"气井不稳定试井测试方案设计提供了参考依据.%The temperature change of the wellbore after shut-in could influence the measured pressure due to the inaccessibility of pressure gauge to the middle to payzone during the well test of"three high"gas well, which causes great interference to the well test interpretation. A dynamic model coupling wellbore-gas reservoir was established by combining the formation seepage model and the wellbore dynamic model. The model is used to study the required depth of the pressure gauge for transient well test, and draw plate of minimum depth of pressure gauge for the"three high"gas well test, and propose the adaptation conditions of the well test at wellhead. The research results showed that the minimum pressure measurement depth for the buildup test ( which can represent the true seepage characteristics of the formation) is mainly determined by the production pressure difference of the gas well and secondly by the production output before shut-in well. When the production pressure difference is greater than 10 MPa, the wellhead buildup test can meet the interpretation requirement of pressure measurement. However, when the production pressure difference is less than 10 MPa, there is a minimum pressure measurement depth, below which the pressure gauge can only accurately represent the seepage characteristics of the formation. This method provides a reference for the design of the transient test of the " three high" gas well.
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