I have an interesting question to share with you about how to estimate minimum mud weight required to safely TD the well.
The question is shown below.
7” casing shoe was set at 6,500’MD/5,000’ TVD. The geologist team in town expects 2 hydrocarbon reservoirs and information is listed below;
Formation sand A: Expected depth 5,500’ TVD, pressure gradient is 0.48 psi/ft.
Formation sand B: Expected depth 8,800’ TVD, pressure gradient is 0.49 psi/ft.
The planned TD is 9200’MD/9000’TVD and the drilling team requires 250 psi overbalance while drilling.
What is the mud weight required to drill the well with 250 psi overbalance?
First of all, let’s draw a simple diagram like this.