Extended Reach Drilling is getting more and more popular all over the world even though there are a lot of difficulties compared with conventional drilling. The main reasons are it reduces exploration costs significantly, because there is no need for additional platform construction or subsea completion and it has great advantages when considering environmental concerns. Recent progress in the development of drilling instruments and drilling simulation techniques have also made possible and enhanced the attractiveness of Extended Reach Drilling.
For the same reasons as above, the Johbanoki-2 well was planned in order to explore the C-satellite structure that is about 4, 000m away from the Iwaki-oki platform toward the south-south-east. The platform itself is located about 40km off the east coast of Fukushima Prefecture.
The total measured depth of the planned well is 4, 960m, the true vertical depth is 2, 275m and its maximum inclination is expected to be around 76 degrees. Therefore, the well will be the first Extended Reach Well in Japan.
This paper reports how the first extended reach well was planned including the following; trajectory plan, casing plan, torque and drag prediction, mud plan, hydraulics plan, bit plan, cementing plan, logging plan and completion plan.
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