Way back in the day with deep sea drilling they used to just let it all flow out if you know what I mean. Now in the PC world and all, we have to watch what we spill, give rattail’s fin about other critters, yadda yadda yadda. The japanese, being the ever inventful gadgeteers they are, have outfitted their newest and top of the line drill ship CHIKYU (japanese for “earth”) with a Blow-Out Preventer (BOP) for just those uncomfortable circumstances when the pressure is a little higher than you expected that day.
“Further Blow Out Preventer (BOP) makes safe drilling even where there is unexpected high pressure flow of gas, oil or other formation fluids from the well.”
The before picture (left) shows traditional “riserless” drilling and the after picture (right) shows the riser drilling system equipped with Blow-Out Preventer.
The traditional, riserless method has the advantage that many holes can be drilled, but
“The disadvantages are corruption of the borehole wall due to seawater penetration[...]. Difficult to drill deeper than 2,000m below ocean floor, because of the hole cleaning and stability problems.”
So basically, while you can drill more holes and get around more, your limited in penetration and your hole gets mucked up more easily. You’ll get that extra inch (500m) with riser drilling system that
chics geologists love, while staying cleaner and not spreading your muck to others around you. Not only that, but the CHIKYU scientists and crew offer a long-term downhole monitoring system:
“The long term borehole monitoring system observing crustal change is developed. In the future, earth observation network will be prepared by linking several observation boreholes by cables on the sea floor. It will contribute to our society such as disaster prevention.”
Now you can plug up your hole, keep track of its contents and avert a disaster to society all in one package. Gotta love those japanese!