测试流量不合理对修正等时试井产能曲线的影响

修正等时试井是目前气藏常用的产能试井方法,试井过程中测试流量的选择对试井的结果有着重要的影响。从气体不稳定渗流理论出发,得出每个测试流量存在极限泄流半径的新认识。据此对修正等时试井的理论基础进行了分析研究,得出在试井过程中测试流量的选择对试井的结果有着重要影响的结论,并分析了测试流量过大或过小时修正等时试井产能曲线的形态及误差。进而指出修正等时试井的适用范围,提出了修正等时试井应该根据储层物性确定测试流量的原则。研究成果对完善修正等时试井测试气井产能方法具有指导意义。

Impact of irrational tested flow rate on the deliverability curve of the modified isochronal test

The modified isochronal test is a universal method for deliverability test for a gas reservoir, during which the selection of flow rate test has significant effect on the result of a well test. In this paper, from the theory of the unsteady gas seepage flow, a new recognition that there is a limit on the radius for each test flow rate has been achieved. Based on the new recognition, the theory basis of the modified isochronal test is analyzed, and a conclusion that the selection of flow rate test plays an important role in the test results has been drawn. Furthermore, the shape and error curves for deliverability has been analyzed under the conditions with excessively large or small flow rates to the modified isochronal test, based on which the application scope of the modified isochronal test is shown. Moreover, the modified isochronal test should be based on the principle that the flow rate is determined by the physical properties of reservoirs. This shows an important guiding significance to a well's deliverability test when using the modified isochronal test.