This topic will cover about pressure profile both drill pipe and casing pressure while kill a well with wait and weight method.
Drill Pipe Pressure
Firstly, we will take a look at the drillpipe pressure. When kill weight mud is displaced in the well, drill pipe pressure drops as per the drill pipe schedule. Once kill weight mud is to the bit, drill pipe pressure is maintained until the well is killed. A pressure profile will look like the following chart.
Casing Pressure
Secondly, we will take a look at the casing pressure. The casing pressure will increase because gas expansion while it is being circulated. The maximum casing pressure occurs when gas reaches at surface. Then casing pressure will drop rapidly because gas is coming out on surface. Once gas is totally removed from the surface, there is still some casing pressure due to original mud weight. The casing pressure will gradually decrease and drop to 0 psi which means the well is killed with the kill weight mud. A pressure profile demonstrates how casing pressure acts while circulating.
I wish these two charts would help you understand about wait and weight method.
Reference books: Well Control Books
