After one month of
drilling, the Woodford Shale Formation was encountered, indicating that the
Devonian formation was just below. Extra care was taken in drilling thru this
shale as it had caused problems on the #1 L.L. Butler some years earlier.
Although very hard,the shale is very brittle and tends to "slough"
off into the well bore. The drilling of this shale was critical to the success
of #1 Maria and so the drilling rate was greatly reduced. Discovery Mud Logging
had been tracking the progress of the drilling since 10, 000 ft. and were of
great assistance in identifying formation types and their composition.
By using logs from the #1 L.L.
Butler, as a comparison, geologist Del Sloan was able to predict with great
accuracy the top of the Devonian formation. Using computerized logging
equipment, the rate of drilling can be observed and thus the type of rock
identified. Cuttings from 'downhole' affirm this identification. This rate
helped the team determine when the Devonian had been encountered, as seen in
the MudLog below.
The well officially achieved
"TD" on 27 August at a depth of 12,576 ft. At that time the well bore
was 'shut in' and a Drill Stem Test (DST) was performed to test for hydrocarbon
flow and pressure. The results were impressive and the decision was made to
complete the #1 Maria. In subsequent days, pumping equipment was installed.
Again the well was 'shut in' and tested for potential. The well achieved 543
barrels of oil and no water was produced. The #1 Maria was a success.
-------TD Mud Log