深层多压力层系气层判断新方法

随钻地质录井只能对单一压力层系作出准确的判断,对于钻遇多压力层系的气层探井,由于下层岩屑经过上部气层时受到上层气体污染,影响气层位置的准确判断。针对流钻欠平衡钻井的特点,建立了气体侵入模型,并进行理论推导,该模型通过测量井底随钻压力、温度数据的变化进行气层位置判断,由于实测的井底压力、温度数据是在打开气层的第一时间检测到的变化,因此该方法能够比较准确地确定不同压力层系气层的位置,能够排除地质录井和测井解释带来的误差,完井测试表明,该方法测试的气层位置较为准确,为深层多压力层系的勘探提供了一种新方法。

New Method for Gas Reservoir Identification in Deep Multiple Pressure Layer Series

Geological logging-while-drilling makes an accurate judgment only for the single pressure layer, but while meeting multiple pressure layer series during the exploration well drilling that will affect the accurate judgment of the position of the gas reservoir due to lower layer cuttings will be polluted by the gas of the upper layer. In accordance with the characteristics of Flow-Drilling under balance pressure drilling, we establish the gas invaded model and conduct theory derivation. It determines the position of the gas reservoir by measuring the changes of the bottom pressure and temperature while drilling operation. Because the bottom pressure and the temperature data are measured at the first time of drilling in the gas reservoir so that the method can determine the position of gas reservoir in different pressure layer series quite accurately. This can remove the error of the geological logging and log interpretation. Well completing test shows that this method is very accurate and provides a new means for the exploration of multiple pressure layer series in deep zone.