Method for Determining Static Pressure for Horizontal Well Short-time Shut In

In consideration of the situation of no buildup test for horizontal wells because of condition restriction, it is proposed that the method of using unbalanced pressure to correct calculated formation pressure (static) during short-time shutin of maintenance. The method is theoretically reliable of easy operation, by which the bigger error induced when measured bottomhole pressure used instead of static formation pressure is avoided. It is used for data correction of horizontal wells of 2 unsaturated sandstone reservoirs in Tarim Oilfield, the accuracy of static pressure valve is obviously improved after the correction, by which reliable formation pressure data are provided for dynamic analysis of reservoirs and practical for horizontal well testing.