Method of Rapid Stabilizing Shut-In Drillipipe Pressures for Blowout Wells

Abstract A new well control method is proposed to shorten the drillpipe pressure stabilized time after shut-in. Long stabilized period is extremely harmful to well control, especially for unstable well-hore, pipe will probably be stuck due to the long shut-in time. Our new method is proved simple, practical and robust from the test results of computer simulation, physical model in full scale and application on site. It provides a new way of well control. The process of pressure buildup after shut-in is now under control. The stabilized time is shortened and the influx of invaded reservoir fluid is decreased greatly. Thus the well control becomes easy. In our new method, using a mud or cementing pump, intermittently a certain amount of drilling mud is pumped into wellhore at a small flowing rate, resulting in the desired initial shut-in drillpipe pressure. Wild cat well, exploration well and development well are required a different initial shut-in drillpipe pressure. In terms of the pressure buildup after the first batch of drilling mud, The next pumping time and mud volume to be pumped are determined by the computer model. Our study set up the mathematical model to determine the desired initial shut-in drillpipe pressure through pumping and the computer program is coded for application on site.