Patent attributes
A method of drilling and fracturing a well includes installing a drilling/frac adapter on a lower wellhead housing. The drilling/frac adapter has a higher internal pressure rating than the lower wellhead housing. The operator drills through the drilling/frac adapter to a desired depth, then runs and cements a casing string in the well. A lower packoff is installed in an annulus between the casing hanger and the lower wellhead housing and an upper packoff is set in an annulus between the drilling/frac adapter and the casing hanger. Frac fluid is pumped through the frac tree into the casing string at a higher pressure than the pressure rating of the lower housing but less than the pressure rating of the drilling/frac adapter. Then, the upper packoff and the drilling/frac adapter are removed from the lower housing and installing an upper wellhead housing on the lower wellhead housing.